Misfire off idle when warm, PCM 454 ... ideas?

[cadunkle]

'89 Saltare PCM 454, rebuilt 2007. I've noticed a misfire off idle at light throttle and 1000-1400 RPM. Only happens when warm and has been running a while. Feels almost like the ignition just cuts out for a split second. When it happens my voltage gauge drops from 14-ish to 12.5 or so and climbs back up. I don't see my tach dropping at all though. It's brief, but very noticeable. Does not happen at idle, does not happen when moving on plane at 2000+ RPM (either that or I can't feel it).

Not sure if this is a new thing or if it has been there forever. I don't remember ever noticing this though. I actually don't drive it very often, since I spend most of my time behind it. But I think my usual driver would have mentioned it

Plugs and wires recently replaced. Carb is brand new and runs well aside from needing larger accelerator pump discharge nozzles. Did not do the cap and rotor (stupid), though cleaned some light carbon tracking off them the other day and it made no difference. Though I'm on vacation I might run to town tomorrow and try to get a cap and rotor just to rule that out.

Possibly related, the boat is hard to start when hot. I never noticed this as I usually have the engine running the whole time I'm out. First start of the day it fires right away, if you let it sit for just a couple minutes it'll fire right up, 10-20 minutes and it's hard to start.

At first I thought I was just flooding it, but what was interesting is it was like there was no spark while cranking. Crank and no attempt to fire until I let go of the key, then as soon as the starter would stop turning it would briefly fire but not start. On a hunch I pulled the little plastic PCM cover off the back of the engine and cleaned the connections on the ballast resistor and on the main breaker. This seemed to help as it now starts easier when hot.

So I'm thinking maybe there are some more dirty connection, or possibly a bad ballast resistor or coil. What should the resistance of the ballast resistor be? What should voltage at the coil be? Any particular wires or connections to check? Anything else I should be looking at?

[bdumas35]

I think you may be on the right track with ballast resistor. Been down this road. Good Luck.

[csuggs]

Ballast resistor or coil. I have been fighting almost identical symptoms all season. Everything would run great when cold, but when it gets too hot it would not start, usually resulting in a flooded engine. Also, it would "miss" after I had flooded the motor (like the plugs were wet or something). I had the carburetor rebuilt and changed the squirter on the accelerator pump because of a "stumble" on my hole shot. Long story short I was chasing a problem in the carburetor that didn't exist and it turned out to be the coil. I had replaced the coil over the winter because it was the only thing left of my ignition that was original. Yesterday I switched to my old coil, installed the original #25 squirter, and was out all day with NO problems. It was a hot day, we stopped and floated twice for about an hour each time, and it started right up each time. Never missed a beat!

[cadunkle]

So in your case it was which? The ballast resistor or the coil? What resistance ballast resistor should I get? or should I replace the coil with one that does not require a ballast resistor?

[csuggs]

So in your case it was which? The ballast resistor or the coil? What resistance ballast resistor should I get? or should I replace the coil with one that does not require a ballast resistor?

I replaced the coil last winter with a new coil I bought from skidim. Turns out that one was bad and I put my old coil back on yesterday - problem solved. My ballast resistor is original.

I don't even know what the ballast resistor does and some folks say you don't need one with electronic ignition. But for whatever reason when I installed electronic ignition 3 years ago I kept the ballast resistor in the circuit and it has always worked fine - that is, until I replaced the coil last winter needlessly. Maybe the new coil doesn't work with the ballast resistor, but my old coil does so I'm staying with that!

[cadunkle]

ballast resistor drops voltage to the coil and more importantly to the points so they don't get burned up so quickly. I think running a coil made for a ballast resistor without one will make the coil run hotter and not last as long. Running one made for no resistor with a resistor will give it lower output and maybe cause misfires.

I was just looking over the ingition, it's triggered by a Pertronix Ignitor II (I dislike Pertronix, but that's a different issue). It's wired with power from the coil... Which IIRC it needs full voltage. I tried calling Pertronix to confirm but they don't open until 10:30 (West coast). So came back inside to look up install instructions and only found them for the original Ignitor (not II) but it says needs full voltage, not through a resistor. I'm going to go change that wiring around and see if it runs any better.

Also, my resistor is 1.3 ohms... Which I think is in the ballpark of what they should be?

[cadunkle]

I changed the Pertronix unit to be get full voltage from before the resistor. No change in the misfire. I then pulled the distributor plate out and lubricated the mechanical advance assembly which was not working smoothly, but was advancing. Put it back together and checked timing which was good at 10*.

By that time Pertronix was open so I called them. Waited a long time on hold, I'd place it around 12-14 minutes. I did speak with a friendly and helpful tech who recommended I give my coil full voltage and bypass or remove the ballast resistor completely. Mentioning something about how it's their recommended way to install since the Pertronix can pull a higher load from the coil. I asked if this would harm the coil or shorten its life since it's labeled "requires external resistor", and the tech said it would not harm the coil. So I gave the coil full 12+ volts and it seems to have fixed it. There was no misfiring on my test drive. Through trying all this the boat seems to start easy when warm, but I'll find out for sure later.

Oddly though I now seem to have a charging problem. At idle and lower RPM sometimes my alternator will stop charging until I bump the RPM above 1500 or so. It's one of those stupid self exciting ones. I'll try checking and cleaning connections and hope for the best.

[csuggs]

Excellent! Let us know after you've had the chance to run it through its paces!

[cadunkle]

Alright, turns out the misfiring isn't fixed. The problem seems to be a reuslt of the alternator not charging. It runs better and starts easier now that the Pertronix and coil are getting full voltage. It will still misfire when the alternator stops charging. Seems to happen now and again at lower RPM (1500 RPM or less), and then will misfire in that 1000-1200 RPM range. If I go back to neutral, blip it to 1500 so the alternator starts charging again, then go back to cruise at 1100 RPM no more misfire. Not sure what's causing the alt to stop every now and again, though the Pertronix clearly wants 14v to run best.

[rludtke]

Alright, turns out the misfiring isn't fixed. The problem seems to be a reuslt of the alternator not charging. It runs better and starts easier now that the Pertronix and coil are getting full voltage. It will still misfire when the alternator stops charging. Seems to happen now and again at lower RPM (1500 RPM or less), and then will misfire in that 1000-1200 RPM range. If I go back to neutral, blip it to 1500 so the alternator starts charging again, then go back to cruise at 1100 RPM no more misfire. Not sure what's causing the alt to stop every now and again, though the Pertronix clearly wants 14v to run best.

The Alternator's nominal output is 14 volts, while the battery is 12 volts. This is why the altrernator can charge the battery- because it is capable of a hight voltage potential, and therefore able to "force" current to run into the battery instead of out. So, whith this in mind, if your alternator stops providing 14 volts of current, the ignition will see battery voltage (12 volts or possible less). I don't know for sure, but my guess is that your ignition system may be operating only marginally, and does not like the 2 or more volts drop in power when the alternator is off.

So, obviously fix the alternator, but perhaps your ignintion system requires some attention too?

[cadunkle]

Well clearly that is the case. I think the ignition sytem is fine aside from the Pertronix not liking the low voltage. There doesn't seem to be a voltage drop from the battery to where I tap power for the Pertronix and coil, so I'm not too worried about that.

My main concern now is why the alternator charges fine at higher RPM but occasionally drops off at lower RPM. It's one of those goofy GM jobbies that needs to be revved to 1500 or so before it'll start charging, then it'll charge at all RPM... Aside from occasionally cutting out at lower RPM. What could cause this? I'm not familiar with GM charging systems so not sure what to check or test, or if it's just a matter or replacing the alternator. Not sure that it's a completely bad alternator though since about 95% of the time it stays charging like normal. If I do replace the alternator is there a drop in replacement (this is a '89 PCM 454) that does not need to be revved to start charging? Preferably a higher amperage output too? Thanks!

[rludtke]

I think it is a failure of the voltage regulator that is causing the voltage interuption, which I am pretty confident is built into your alternator. I think an alternator replacement is probably needed.

[premierproperties]

I'm going thru the identical problem as we speak....When out on the 4th weekend my boat all of a sudden would start to miss in the upper RPM range while pulling my son wakeboarding...it progressed to a very aggravating stall when idling through a looooong no wake channel.Every few minutes it was stall... turn the key and would fire right back up.
I noticed that my voltage was low on the gauge, so I pulled the alternator the next day and had it tested(not sure if they checked it properly tho). The Napa I took it to said it seemed to be fine, but they didnt seem to know how to test a non-modern alternator.... as it turned out the belt was loose and it was slipping.
Voltage now reads about 12.5v off idle. I replaced the coil this weekend and still the problem exists
I'm not sure if this is coincidence, but this all started after I installed the new stereo/amp.
I'm gonna order new wires/cap/rotor from skidim today, as the existing ones look like they haven't been replaced in a while. Let me know what you find to be the culprit.

[cadunkle]

Just looking though some video from vacation and found one of this issue I had meant to post. I never put a final resolution so I'll update. To anyone who is having a similar problem this amounted to low voltage to the Pertronix unit. Resolution was two step, bypass ballast resistor entirely to get full voltage to the Pertronix and coil, and cleaning all power and ground wiring and connections fixed the alternator not charging at lower RPM issue.

Video I found of me demonstrating the problem... You can clearly see the relation between the misfire as you hear it/see it on the tach, and the volt gauge reading.


http://youtu.be/zYPbRKTYd8E

[cadunkle]

Problem came back today, even when volt gauge showing 14+ volts. Don't have my multimeter with me so can't check on voltage to the coil and Pertronix. Was misfiring bad at idle and off idle, even up to 1800 RPM surfing. Wakeboard speed 22.2 MPH 2300-2500 RPM (tidal, changes each turnaround) no misfire and was smooth with a steady pull. ADjusted carb idle speed and mixture since I hadn't changed that since running MTBE (non-ethanol) gas a couple weeks ago on vacation. Idle improved slightly but still misfired just the same. Strange thing is after 20-30 minutes misfiring at idle it went away and ran great for a while, then as I pulled up at the marina it started misfiring again as I loaded on the trailer. Definitely a flaky electrical thing going on.

I think I may replace the coil since it may well be original, cheap and can't hurt. Any recommendations for a marine coil that doesn't need a resistor? Or just use automotive stuff for this part (epoxy potted necessary with vibration?). Probably change plugs too since it's been two seasons on these and plugs are cheap.

[cadunkle]

Wow, disregard my shenanigannery until I get a chance to test this pig on the water again. Apparently I had the cap on backwards, so it was cocked on the locating pin. Rotor may have hit and eroded 3 temrinals. So I had too tight gap there and too large on other side. Also my rotor set screw/plate was loose, allowing rotor to vary position a bit. Advance was not working, slight rust on the slots of the plate the rotor rides on was creating a lot of friction. Quick clean and lube and seems to be advancing and returning to correct initial every time. Need to stay on top of these marine distributor advance assemblies.

Anyhow, boat felt very sluggish today, lack of timing advance is why. Seems to rev a lot quicker in neutral now, and start easier. Will be ordering new cap and rotor tonight along with throttle/shift cables and ends. Don't recall it feeling like that or misfiring at all last Sunday, but whatever. Hopefully it's fixed. I'll go crawl back in my hole now.

[wotan2525]

I was going to say after reading the first post that this sounded like a timing issue for sure. Glad you're on the right path!

[TitanTn]

I'm just catching up on this thread and it reads like a soap opera! I can't wait for the next episode. So many twists and turns...

[cadunkle]

lol Yeah intermittent problems are the worst, just when you think you've got it sorted, it comes back.

[cadunkle]

I'm pulling my hair out on this one. Replaced damaged cap and rotor and put a new coil on it. Dropped in tonight and got in a set, boat ran fine. Pulled my buddy and halfway through his set it started misfiring at idle, only when in gear. Just missing badly and running rough, wanting to stall. Back to neutral and smooths out to a nice idle. Tried adjusting carb idle mixture and it was dead on in neutral. I put the new coil on the factory resistor since it said to use a resistor. I stopped and changed that to get full 12v. It then seemed to run fine.

After changing to full 12v no resistor I revved it, smooth. Put it in gear, smooth. Then my buddy yells "Stop!" ... Nobody pulled the rope in and I ran over it. :mad: There's a first time for everything. Jumped in and worked out a couple loops, then getting close to shore so had to drop the anchor. River current is swift, 8 MPH at full swing. Being anchored it was hard to hold myself under the boat and work the tangled mess. Finally got it. Gave up on riding since it was getting late and tide was getting low so needed to pull out.

So before heading back I ran the boat for 10-15 minutes trying to get it to misfire. Ran great idle to 4500 RPM. Head back to ramp and right as I'm maneuvering into the marina against the swift current, it start misfiring and wants to stall. If I continue to give throttle, pumping a bit, it'll accelerate and smooth out at higher RPM. So I hauled ass into the marina and bumped quickly in/out of gear to get to dock and on trailer.

From my testing, it seems like when it starts misfiring if you let it sit 5-10 minutes it'll run fine... for 5-10 minutes, then misfirire badly at idle but if you get it into higher RPM it'll misfire there. At idle in gear when misfiring I read 14v on gauge.

I'm thinking it's ignition. I'm tempted to try my old coil, but I would think new Mallory coil should be fine. It did same thing with old coil a couple weeks ago, just not as bad. Distributor is factory Mallory with a Pertronix (original version). I'm also thinking the Pertronix might be bad. I'm tempted to just buy a new Mallory Marine distributor with electronic pickup built it.

This problem is so difficult to diagnose since it's so intermittent. It may work fine for weeks or months, then show up again. What do you guys think?

[wotan2525]

Sounds like a real head scratcher! I've been chasing an intermittent miss for the last few weeks and I think I finally worked it out yesterday. The "tell-tale" was that it missed while at speed yesterday afternoon and when I went to start it again my ignition breaker had popped out (the one right next to the key.)

I did some looking around and found that the old wires from the original alternator (I converted over to a 1-wire setup) were zip-tied together in a bundle and resting on between my intake manifold and one of the heads. One of these wires had melted through (no doubt while I was having cooling problems earlier this year) and was shorting out on the block! The way the cables were bundled was to prevent this from happening, but obviously over time they had wiggled loose and it was occasionally making contact with the head. It was really just dumb luck that I found it!

Not to say that this would be your problem... but..... have you checked all of your wires to make sure they are far enough away from hot parts?

[cadunkle]

I will check my wires for abrasion and any possible intermittent shorts. I think I'm good on that but I haven't looked closely the whole length around the engine. I need to keep a multimeter on hte boat to test when it acts up. Really I wish I had a set of points handy for this distributor to rule out or confirm the Pertronix module. I suppose I could order a set and see what it does.

Right now I'm thinking it's heat related. Maybe Pertronix getting hot and cutting out, since it ran fine for a bit after sitting while I untangled the prop. I'm about ready to bite the bullet and get a new distributor., since mine is old and could use a proper rebuild (nothing that should cause this though, from the light mechanical wear).

I'm considering...
Mallory Unilite: http://www.summitracing.com/parts/MAA-YLU624AV/
Power filter for Unilite: http://www.summitracing.com/parts/MAA-29351/
New ballast resistor: http://www.summitracing.com/parts/MAA-700/

I already have this coil (http://www.summitracing.com/parts/MAA-9-29716/), which is identical specs to the one recommended in the Unilite manual (http://mallory-marine.com/Portals/0/downloads/marine/pdf/Unilite.PDF), but with a marine rating.

Any comments or thought son these parts or the problem in general? Does anyone know the differences between Unilite (YLU) and magnetic (YLM) distributors? The YLM is more expensive but I've also heard the YLU maintains more accurate timing, which makes sense given the small size of the magenetic wheel on the YLM. Of course at 5000 RPM or less it probably doesn't make much difference. Any reason why the YLM might be preferable? Any thoughts on MSD? They offer a magnetic pickup distributor. Anyone else to consider? Mallory and MSD seem to be the only players in the marine game. Pertronix makes one but I won't spend a penny on anything Pertronix, they've burned me several times and won't stand behind their products. Really a terrible company with a shoddy product and of course they won't stand behind it.

[wotan2525]

My friend builds dirt-track engines and after I had a number of problems with my pertronix, he recommended this chinese-built unit. http://www.kmjent.com/cart/product.php?productid=2264&cat=20164763&page=1

I was skeptical, but it has worked flawlessly for 3-years now. It's not marine, and I don't know how you feel about that, but if anything it might be a cheap way to test your existing setup. Just throwing it out there. I wouldn't blame you if you thought it was junk or wanted to spend the money on a marine distributor. For me -- the price was right enough to compromise and I've been very pleased with the performance.

[SquamInboards]

The pertronix is a likely culprit here, in my opinion, and I bet if you put in the new mallory dist. you'll be wondering why you waited so long. I've had mixed results with pertronix.

[cadunkle]

Glad I'm not the only one with Pertronix issues. Thanks for the China link. $40 would be a cheap test, but I don't trust China parts and I buy American wherever possible to keep jobs here. One option I saw, someone locally selling refurb YLM distributors for $150. I'm tempted to save a few bucks and go that route compared to YLM new cost of $482. http://www.ebay.com/itm/Mallory-YLM624BV-9-26307-Marine-Distributor-Big-Small-Block-Chevy-262-454-V8-/251119746594 After this fiasco I may just go all new parts though so I'm not doubting anything or worrying about having loose bushings, corroded advance mechanism, etc. Where I boat is really inconvenient to break down, due to large shipping traffic and fast currents, so I want it to be spot on.

I'll mull it over a bit more and see if anyone else comments before ordering. Would be nice to get the stuff this week and test so I can ride this weekend.

[cadunkle]

I never replaced the intake gasket, and this seems kind of like a vacuum leak. Only other thing it could be. What intake gaskets do I use on an '89 PCM 454? Square port? Oval port? I'm a Ford guy, so I don't know Chevy parts? I may just order distributor setup along with intake gaskets and do it all. I need to change my oil anyway.

[cadunkle]

Well I'm pretty sure it's oval port, so that's what I ordered. Also got all the Mallory parts. Everything arrived today but unfortunately I'm sick and really not feeling like pulling an intake. Hopefully I'll have it done at some point this weekend and tested. One more day of taking it easy and hopefully I'll be back to normal. I'm fairly confident this will resolve my problem.

[cadunkle]

My cold was kicking my arse last weekend so didn't get to work on the boat. I was busy working on other projects, and have been all week so no rest for the weary. Almost have it shook.

Anyhow, I got to working on the boat tonight and just called it quits since it's dark (gotta work on enlarging garage to get it inside). Intake is off and head surfaces cleaned. Good news, the old gasket was squeezed out on several ports and actually quite torn on one port. I highly suspect it was leaking and causing the intermittent idle, stumble, and general slightly lean feeling. Doubt it was causing the misfire as that seemed to be ignition related and just a few cylinders.

Without further ado...

http://i121.photobucket.com/albums/o234/cadunkle/Supra%20Saltare/IMG-20120830-00149.jpg

http://i121.photobucket.com/albums/o234/cadunkle/Supra%20Saltare/IMG-20120830-00144.jpg

http://i121.photobucket.com/albums/o234/cadunkle/Supra%20Saltare/IMG-20120830-00143.jpg

http://i121.photobucket.com/albums/o234/cadunkle/Supra%20Saltare/IMG-20120830-00138.jpg

Port side took forever to remove, came off in tiny pieces. Starboard was fairly quick and easy, gasket wasn't so hardened. Also learned the intake is a cheap China knockoff. I could run to the local speed shop and pick up something not foreign but not sure it's worth it for a low RPM engine. I'll probably leave it be. I might take this opportunity to replace the shoddy rubber fuel line with a proper metal line, we'll see how motivated I am tomorrow when I get it back together. If not it'll get done this winter when I pull the engine to repair some oil leaks and do a thorough inspection. I suspect the rear main is leaking, or possibly the oil drain hose/fittings. Either way the engine will have to come out this winter so I'll take care of all the of all the odds and ends then.

[cadunkle]

Putting this back together now. Any preference on a BBC to leave exhaust crossover open of blocked? I was going to block it in hopes I wouldn't need to run the phenolic spacer anymore, but the intake gasket kit came with restrictors that look like they cut the crossover flow in half or third. I'm gonna try running these and see how it goes. I do run in cold weather, down to mid 40s water temp and pretty cold air, so I was thinking it may be overkill to block it off completely.

[wotan2525]

I can't remember if it was my head gaskets or intake gaskets (or both) that were blocked off.... but I know something I installed was blocked off. I didn't really understand the difference, but I know I had to swap out some OEM ones for some FelPros to make sure they matched the configuration that I took off. Does that help at all?

Also, I've never run a phenolic spacer and I've never had a problem.

[cadunkle]

Sounds like intake gaskets. There are no blockoffs on head gaskets. Just coolant passages are blocked at front (if you reverse, it will overheat from coolant bypassing the whole engine) but all engines are like that. Exhaust crossover is an open exhaust port in middle of each head that crosses over through the intake to the other head. Heats up the carb on cold days to prevent icing and improve driveability before the engine is warmed up. Also old style heat stove chokes work via the exhaust gas in the crossover passage. On hot summer days the exhaust crossover can contribute to vapor lock and carb boil over.

Anyhow, my intake is installed. Not sure of any areas of concern on a Chevy (except maybe those that had failed on the old one). I used RTV on both sides of the gasket around each coolant passage, and brushed on gasket sealer on both sides of the rest of it to keep it in place and help seal around the ports. I used a bead of RTV on the china walls. Hopefully it seals up with no leaks. At some point this weekend I hope to install the carb, distributor, and wire up the new distributor and ignition components.

If this doesn't fix my misfire, I'm either giving the boat away or putting a 460 Ford in it and using the BBC as an anchor.

[cadunkle]

Been busy as heck, and a lot of rain lately. Even a tornado in the next town over! It stopped raining after I got home today so I put the carb and distributor in, wired it up, put all my plumbing back together, etc. Was ready to fire and realized I forgot to get oil and a filter! Oh well, I'll pick that up tomorrow, and change oil and test fire either tomorrow or Friday, pending weather. Rain forecast all weekend so no rush I guess. Meanwhile summer is slipping away... Only two months of boating season left.

[cadunkle]

Got it back together and running. Something isn't right though, It wants one idle mixture screw all the way in and the other 1/4 to half turn out. Float levels golden. Primary accelerator pump discharge nozzle was slightly loose. No dripping from boosters. Thinking blown power valve. Gotta pull the carb and check power valve and go over all that. Carb is less than a year old, mildly irritated. Thoguh it did get a little wet under the cover during a heavy sideways rain... Oops. Wondering if I'm ever gonna get on the water before the season is over!!

[Jetlink]

Didn't you run well into November last year? How are those heated seats working by the way?

[cadunkle]

Yes Jet, I think it was the first or second weekend in November. I'm planning on doing the same this year. Definitely gets cold, but it's worth it. Personally I push myself harder in October and November because I know the end is near, and the cold water is incentive not to fall! Gonna be wet suit weather if I get out this weekend, last weekend on a friend's boat was brisk with 66* water. The heated drivers seat is working great. Definitely comfortable to sit down in that, eventually I'd like to heat the spotter seat as well. The heater is nice too, though I'd like to plumb the vents in nicely instead of just having blower hose draped everywhere.

So I finally got to work on the boat tonight. Pulled the bowls and blocks, cleaned everything well, and put together with a new power valve. It now idles a lot nicer with more reasonable idle mixture screw adjustments at about 3/4 turn out on each. Still a bit far in for what I'd consider normal, but they're even and it seems to run nice so it's time to water test it. The old power valve did not leak vacuum, it seemed to work normally, but the needle was corroded or crusty... from water getting in it. My own fault, but a cheap and easy fix. While I had the bowls off I wanted to try leaning out the primary side a bit. Currently running 72/87 jets but I have a feeling with the stock cam I might be able to drop a size or two on the primaries and save some gas. Didn't change them though as I don't want to change too many things at once.

High tide is about 7:00 PM tomorrow, so I'm gonna try to cut out of work early and test it on the water before I try to get a crew together this weekend.

[cadunkle]

Well the boat ran great with the new ignition system... Until it started misfiring then died and wouldn't restart. Starts easier, idles smoother, idle RPM only varies a small amount when coming back to idle, which I think may be linkage related since I've had it off and on a few times. Runs smoother and I think it may be a little quieter.

Ran great for maybe 20-30 mins. Ran back and forth at 22.2 MPH on the PP like when I'm riding and it was fine for a while. Then made a few WOT and higher speed passes. Ran great. Came off plane and go to accelerate again and I get a bit of misfire in the 1500-2000 RPM range while accelerating lightly. Felt like a lean misfire when jetted slightly lean. Then rapidly got worse over a minute or two and was misfiring at idle, then stalled and would not restart. Give max throttle it allows in neutral lockout and nothing, pump throttle while cranking and nothing. A couple random firings but no real attempt to start. Checked all my wiring and such, seemed fine. Coil was hot (as they usually are), wondering if it was too hot.. But it is wired through the ballast resistor like Mallory recommends.

So... I start paddling. It was slack tide and I had about 20 minutes to cover 3/4 mile or so before the tide started pushing me away from the ramp. See a friend in a MC and flag him down. As he comes up I try starting and it fires and idles butter smooth. Run back to marina with him following and dock the boat. Get the truck, go to start boat to put on trailer and won't fire. Walk it on the trailer and on my way... cursing myself for not bringing a multimeter.

So it hit me like a sack of bricks, going over everything I've done. It felt like a lean misfire this time, different than previously. I've never changed the fuel filter on this boat. *headdesk* I've meant to for the 2 years I've had it but kept forgetting to check what part number the filter was. So get the boat put away and go to pull the filter... It's not a normal oil filter style screw on filter. It's that type of housing but it's an old rusty thick metal filter. Couldn't get it off, it was dark, screw it I'm getting a new one. No idea how old the filter is but doesn't look like it has been changed or cleaned (if serviceable) in forever. Metal canister style filter mounted on starboard stringer below the raw water pump. At this point I'm thinking it has to be a plugged filter. Whole ignition system is new, carb is new. Problem manifests itself after 20-30 minutes of running, and this time right after running hard WOT. I'm thinking it has to be sucking up crud in the filter and plugging it up. Wait a bit and it settles, runs for a bit, and plugs up again. So I'll be putting a new modern style fuel filter on it. Will also be relocating it somewhere not directly under the raw water pump to make servicing that and winterizing easier. Will fill holes in stringers with epoxy and will use 4200 on new holes in stringers to seat out water.. If this does it... I'm an idiot.

[TitanTn]

I think we may have a winner.

[Jetlink]

Geez man, that is a very detailed write up. I think I have to agree though in your suspecting the fuel filter. Sounds like a fuel delivery problem. Either a clogged filter, bad pump or both. Best of luck and hopefully you can still make a weekend out of it.

[cadunkle]

Yeah I try to be detailed when I post this stuff, in case someone else has a similar problem. I hate it when I look up something online, find something maybe useful, and don't see a final success/fail post with results. Along the line with this problem I definitely had a problem with not enough voltage to the Pertronix. Definitely intake leak casuing erratic idle. I threw a carb at it that I didn't really need to buy, but I can use the old 800 DP and new billet base plate on my car when I get that done this winter. The old distributor and Pertronix unit I think are fine. That was a waste, though it does run a lot nicer with the new Mallory YLU setup. Since the bushings and everything else is tight I will probably clean up and lube the advance mechanism on that and sell it since I'm a Ford guy, other than the boat I have no use for 454 parts. Anyone need a Chevy distributor with Pertronix?

Well as usual nobody local stocks quality parts, and you pay a heck of a premium for mediocre stuff. Can get a generic brand aluminum fuel filter and housing for about $50 locally and have it today... Or get a Mallory aluminum setup for $36 online, or a Mallory stainless setup for $89 online. Yeah, shipping and such too, but still cheaper to buy online and at that point I may as well get the better stainless hardware. So I'm about to order one of these (http://www.summitracing.com/parts/MAA-9-37856). Looks like I'll be shooting for a test ride next Sat/Sun and who knows when I'll get a crew together after that. Low tide after work all week so can't get out during the week.

I have a nagging feeling I've been needing something else form Summit for a while and know I've forgot it on the past few orders. Don't know if it's for the boat, truck, car or bike... But I know there's something. I probably won't think of it and will remember right after placing the order. Oh, I also lost a bearing buddy last night so ordered a pair of them from Summit since it'll ride for free with my filter.

I may also pull the pickup from the tank and check/clean the sock since that could potentially be part of the problem as well. Should have the boat done just in time to start breaking ice at the ramp! In all honesty though October is my favorite month to ride. Nobody else on the water and the stars seem to align for low winds in the morning.

[cadunkle]

Nothing is easy. Got the filter today. Pulled the old filter, there was a fair amount of sandy/rusty junk in it and some crud but not as bad as I expected. Likely it needed to be changed.

Went to put new filter on and couldn't get 3/8" NPT to 3/8" hose barb fittings anywhere local. I hate auto parts and hardware stores, nobody stocks normal stuff anymore. So gotta order fittings from Summit that I probably should have ordered originally with the filter. Oh well. Not sure where to mount the filter. Not enough room mounting on stringer in the engine area as bracket places it too low to change filter. Thinking I gotta go forward or back. If I go forward I gotta run a new line from tank as I don't want to splice. Maybe I can put is just past the trans mount area closer to the tank where stringer is full height? I think the blower vent tube will be in my way there though. I could make a bracket out of stainless to raise it up maybe. Alternatively I could run fuel down starboard stringer and mount where I need there, but don't really want to do that. I gotta think about it. Gonna order fittings and should have by the weekend. I'll probably end up making my own bracket to raise it a bit. If I do that it'll probably be under the side of the engine and may be hard to drill holes in the stringer given oil pan in the way. Of course I need to be well below exhaust, which I think I should be fine. Like I said, nothing is easy.

Alternatively I could just get a new filter for the crusty old FRAM setup, clean and paint it, and remount it. I'd prefer to use the nicer oil filter style setup though. The old one is all corroded and rusty.

[cadunkle]

I'm also not convinced it's fuel as last time out when it died and I got it to start and idle to dock and shut it off... then wouldn't restart. I pumped accelerator pump on primary bowl and got fuel spraying good out of the discharge nozzles for several pumps without running dry so there was fuel in the bowls. Correct level? Not sure, didn't pull the sight plug to check (should have!). But there was some amount of fuel and even if it wasn't high enough to feed normally through the metering block it should have attempted to fire with that fuel pumping in. Wish I had checked for spark. Next time I'll check for spark and bring a multimeter to check wiring thoroughly. Thinking of swapping the coil from the boat into my truck to see how it does there, and using trucks coil (known good) in the boat for a test run if this persists. Anyone wanna buy a Saltare, real cheap? Test drive limited to 15 minutes. :p

[wotan2525]

I'm sure you're pulling your hair out but really... what is even left!? Any chance that the carb is flooding out? Could you bring some starting fluid with you and try that to see if it will kick it over?

Are you using a mechanical fuel pump or an electric one?

[Jetlink]

Anyone wanna buy a Saltare, real cheap? Test drive limited to 15 minutes. :p

Haha, I need another boat right now like I need a hole in the head...but you got me thinking...:p

[cadunkle]

Mechanical pump. No fuel dripping from boosters while this happens and don't smell gas unless I keep cranking and pumping throttle.

Break in the rain tonight so tried to get the filter sorted. Was gonna use the bracket from the old filter to raise the new filter a bit. It will fit like that but just barely, and won't give me any room to remove the filter without first removing the new housing from the bracket. They do make a shorter filter which is maybe 1/2" shorter, I think ... Mallory doesn't give height but one replacement for it from another manufacturer does. Verified no room to mount it out back on starboard side unless I remove/relocate the blower PVC line. Then I figured screw it I'll just mount it through top of stringer as is and when I replace filter I'll try shorter filter and see if that comes off in place. Found out I can't really drill holes where I need to unless I remove the fuel pump. No room to get the drill in there. I think I'll go for a solid straight plate and cut to size to mount through side of stringer and mount filter housing higher. I should be able to drill holes that way. Maybe I can get that this weekend.

It was dark by then so I didn't bother trying to move the coil away from heat or try to check anything else out. Forecast is threatening rain through Monday so not likely to make any progress until next week. If it's dry after Monday I can probably get my bracket sorted and coil moved one night then another make the mad dash for the water after work before it gets dark for another test, since it should be high tide in the evenings next week.

[TitanTn]

Whew! I'm tired after reading this! This is complicated!

[cadunkle]

Yeah, try working through it! Driving me nuts. Sent Mallory tech guys an email with a description of everything since it started misfiring and wanting to stall initially. He seems to think my new coil may be bad and suggested getting it exchanged with Summit. I will either do this or try running the coil from my car or truck on it if I get out before I have time to deal with that. Think the Galaxie has a MSD Blaster and the truck has an Accel epoxy potted coil, both high output coils similar to the Mallory and both are known good as I've put thousands of miles on the trucks coil since I got it and tens of thousands on the cars coil. I may try this early this week to test coil, or if I can't get on the water maybe put the Mallory on my truck to test, and keep the Accel handy just in case! Also gotta dig out my IR temp gun I want to check coil temp on my truck and compare to coil temp on the boat. Should be apparent if it's overheating. Sick of wasting time and throwing parts at it.

[Jetlink]

Nothing frustrates me more than to feel like you are just throwing parts at a problem after trying to diagnose it and getting nowhere. Really makes my head hurt sometime because I usually bang my head against the wall or maybe it just feels like that.

[cadunkle]

Finally had some time to mess with the boat. Went out today to test with new fuel filter installed. It ran great for about 20-25 minutes. Apparently made some hunters quite angry so headed to another area to test, seemed fine. Figured maybe it was in fact the fuel filter. Pulled back to dock and decided to stop adn start the engine a few times since it wouldn't restart last time out. Same problem. It started once but after letting it sit a minute wouldn't restart, or would briefly fire but not start. Pulled coil wire and held about 1/2" to 1/2" from intake. Got good hot white spark when cranking. Both bowls on the carb were full and accelerator pumps pumped fine on both sides. Coil was getting 12.4v key on engine off and ~10v with engine running... Seems the variable resistance resistor is doing it's thing. Coil was warm, not hot as it was one time previously.

I did bring a spare coil, the old coil that was on the boat and I suspected was weak. Swapped it on and it fired up instantly no hesitation. Stopped and started severalt iems, instant tap of key start every time. So I'm figuring it's a defective coil. For now I'll leave the old coil on there. I set up a return/exchange with Summit and will send the new Mallory coil back for replacement this week. I'm optimistic that this is my problem at this point.

Big storm coming this week so won't be able to get out this weekend or next weekend with the debris that will surely be in the river. Hopefully in two weeks the river will be clear and I can get a crew together and do some riding. River was 53* today so I hope it stays warm a few more weeks!

[86 century]

Some reports say this could be the perfect storm type of thing headed your way.

The last one sank the andria gail so be careful. Lol