84 Supra Rider 351w No Spark from Coil

[chautauquasun]

Was out for a morning ski and wakeboard yesterday on Fathers Day. Boat ran well in the morning but as usual as it gets hot the holley carb (which needs rebuilt) started stalling. Nothing unusual...been here many times before. However as we started to cruise back to the dock the boat seemed to start to misfire and was running very rough at low speeds but would seem to be better at higher rpm. Got the boat back to the dock and let it cool but then couldn't get it started again. I have never had this issue before. Boat was getting gas but discovered I wasn't getting any spark from the coil wire that feeds the distributor. I have had issues with coils in the past. I went and bought a new coil. No luck still no spark. So I went and replaced the starting solenoid which also goes bad from time to time. Still no spark from the coil. I borrowed a coil from my neighbor who is running the same 351w set up thinking that maybe I got a bad coil and still no luck. No spark when trying to arc the coil wire to the block. The points seem to be getting power and can see a spark when they are opened but no spark at the top of the distributor. I don't believe the stalling problem has anything to do with the no start/coil issue. I am wondering if I have a loose ground wire or something wrong with the key/ignition. I had new upholstery put in and the binnacle was reupholstered and found that there was a ground wire loose when I got it and the instruments wouldn't work. I was able to ground them and now the all work except for the engine hours meter.

Can anyone shed some light on why I am getting no spark at the coil. Pretty sure I have it all wired up correctly. Anyone run into this before? Boat has always run well other than going through coils and starting solenoid from time to time. I have never had this problem before. Any help would be greatly appreciated.



thanks
Dan

[Moor]

In my experiences with points ignition systems, 99% of the time when there is a problem, its the points. If they fall out of adjustment even a few thousands of an inch, they don't work. You can try removing them and cleaning them up with some fine sand paper, then reinstall and gap properly. The pads should be clean and free of any pitting and wear marks. Make sure both pads are still on the points, i've had them fall off before. Or just buy a new set of point since they only cost a few pennies. Check / replace the condenser while your at it. Its also only a few dollars.

[Moor]

I just reread your post, if your burning up coils at an abnormal rate, be sure that your ballast resistor is installed and working properly. Running a points ignition without a ballast resistor will fry your coil relatively quickly.

[chautauquasun]

Would faulty points cause no spark from the coil wire? I have only had to replace the coil twice in the last 7 years so not sure if that is abnormal. I am a novice with engines...know my way around somewhat but where is the ballast resistor? Is that the starting solenoid or is it the porcelain block on the back of the engine? Thanks for the help!!

[Moor]

The ballast resistor is the small porcelain block at the back of the engine. Since you visually identified it, i'll assume that its hooked up. I've never tried to test for spark straight out of the coil. I think you need it hooked up to the distributor and test for spark at the end of one of the spark plug wires coming off the distributor. Are you sure the coil is wired correctly? You also said that you can see a spark at the points? If the spark is making to the points, but not any further, i'd investigate the points. Take 10 mins and clean/reset the points.

[mlaosa]

Agree with Moor. Points on boats can act up due to moisture and build up on them. I used very fine Emory cloth and be gentle with them. Also FYI, make sure your points hold down screws are tight as it can change your dwell- (amount of time they open and close) and gap as well. Recently changed to electronic ignition and haven't had any issues since.

[Moor]

Agree with Moor. Points on boats can act up due to moisture and build up on them. I used very fine Emory cloth and be gentle with them. Also FYI, make sure your points hold down screws are tight as it can change your dwell- (amount of time they open and close) and gap as well. Recently changed to electronic ignition and haven't had any issues since.

+1 on checking the set screw, i've had them loosen up in old cars and kill the spark. Electronic ignition upgrades are very common in boats. My sunsport already had it done when i bought it. Probably one of the best upgrades for an old boat running points ignition. Just for reference, on automobiles back in the day, a points adjustment / inspection was part of routine maintenance that should have been done with every oil change. Its the exact same set up in your boat.

[Blackntan90]

X2 on the pertronix electronic upgrade. No more points to fool with, no issues at all after very simple install. I Love my boat now!

[chautauquasun]

pdate...thanks guys. So I spent last night working on the boat. I had an old Pertronix Ignitor that I was never able to get working. I tried to install it and still no luck with it. So I put in all new points and condenser then put in new plugs. Got the engine started but it ran very rough. It was backing and vibrating and I think missing. I set the gap on the points to .018 but didn't have a dwell meter nor timing light...and I have never used either. I called a guy this morning to take a look at it. I wasn't there, I was at work so he was communicating with me via text and phone. He had an HEI distributor for a 351 ford or so he said. He installed it and it seemed to run okay until he took it out and it was under load. It was bucking and missing so he brought it back and took it out and replaced my points and condenser. He then tried to set the timing and said he gapped the points at .16 but I believe they need to be gapped at .18. Also he said he had to run the timing light on cylinder 3 but everything I have read says it should be cylinder 1. He then told me that he set the time to TDC at 6 but I think it should be 10. Again, I am a novice on this aspect so all I can do Is read. At this point he said that he cant get the boat started. He said the carb is flooded. I told him to squirt starting fluid into it to see if it would fire and it wouldn't fire so at this point I believe the timing is so far out that I wont be able to get it started. He suggested I install a electronic distributor and is willing to help me with the install. At this point I feel I should try to do it myself because I am not so certain he really knows what he is doing. He said the clips on the prestolite distributor are shot and to just replace the whole thing. He also said that there were no timing marks on the balancer. how can that be...has to be at least one right? I think I made a mistake having this guy look at it.

If I am going to go with an electronic distributor what type do you recommend? Is it easy to install? Do I have to reset timing once it is installed? Is it pretty much plug and play or is there a lot of adjusting to make it run right. Any ideas and help is greatly appreciated.

thanks
Dan

[Moor]

I would consider replacing the distributor your self if you feel somewhat comfortable doing it. From what you've posted, I'd be hesitant to let this guy do further work on your boat. I'm not sure why he timed it using the #3 spark plug wire. I ALWAYS use #1 wire. They SHOULD be at least one timing mark on the balancer. if there is not you can buy timing "tape" which is taped onto the balancer once the engine is set to TDC, but that is a last resort. if your guy is having problems timing the engine, i would suspect a worn timing chain, but from the sounds of it he isn't doing it properly if he is using plug wire #3. What was his reasoning for using this wire?
If you have a timing light, or buy a cheap one, you can check this yourself. If the mark is bouncing or moving around when you have the timing light on, they you probably have a worn timing chain. First you need to find / verify the timing mark(s). I'm more familiar with chevy engines, buy IIRC the ford timing marks are very similar and there should be a groove machined into the balancer. IDK the timing spec for your engine, but some google searching should tell you what its supposed to be set at. Maybe someone here know and can post it for you. Points should work ok if they are set between .016-.018", as that is the recommended spec for almost every set of point i've ever touched.

Is the engine hard to start because the carb is flooded, or because the timing is not set properly. Too far advanced and the engine will turn over slow and kind of sound like a weak battery. Too far retarded and it will backfire through the intake / carb and not start. Also double check the firing order and make sure he has the spark plug wires in the correct positions on the cap and the spark plugs.

upgrading to an electronic distributor

is pretty straight forward. I have a Mallory unit on my boat, but have a pertronix on my old muscle car. Both work very well. The Mallory is better imo. The timing will need to be set anytime you remove or replace a distributor. It would be wise to verify your timing chain is good or bad before you look into distributor upgrades. Theres nothing wrong with a properly functioning points igniton, they just require a little maintenance from time to time.

[chautauquasun]

I agree about having him do any more work. Said he worked for a Supra dealership in GA so I trusted him. He said the timing light wouldn't work on cylinder 1 so he used 3. Again everything I read says to use 1. He left it in worse shape than what I had it in. He said that because my carb is bad and the distributor clips aren't tight he couldn't tune it. That maybe the case but at least I had it running before he touched it. OneAnyways, I think I am going to upgrade to an electronic distributor. Does anyone have any recommendations on the brand and model. I have looked at Mallorys in the past. Is this something I could order on Summit or Jegs? Any help would be appreciated. I believe the engine is a left hand rotation does that sound right. Also, when I started to check the spark plug wires the other night prior the guy coming over, they didn't seem to match any of the diagrams I pulled up for this engine. Does anyone have the right wiring diagram for the plug wires for an 84 PCM 351w?

[mlaosa]

Again--x2 for what Moor said. I'm a senior master ford tech and have never heard of hooking timing light up to anything but #1 plug wire. Run far and fast from that guy! I run my conbrio right at 10 degrees BTDC. As far as the clips on the distributor cap not holding cap down tight, I had the same problem with my first comp ts6m. Replaced cap/clips/rotor and fixed. Not saying that is only problem with yours but if it's loose then it's hard to get good spark from the rotor to cap. I would certainly pull the cap and look at the contact point at top of rotor and beneath cap and look for any signs of arcing or "burn" marks. Mallory makes great electronic distributor.

[chautauquasun]

Hey guys thank you for entertaining this thread as long as you have. You have given a novice a lot of good information. Question for mlaosa... I have read just as you have said the 10 is TDC but I found an old PCM manual on line that is saying the bolt down distributor is 10 but the clip down is 6. I believe I have the clip down prestolite. So do you know if it should be 6 or 10. I have a copy of the manual if you want me to email it to you. I am going to get the carb rebuilt so that I know it is correct then really dig into this further using the manual. Another issue is that my tach has worked in a long time. I think I need a function tack to set the idle timing don't I?thanksDan

[chautauquasun]

see the attached page from the manual

[mlaosa]

Good catch. Yeah my boat has the screw down and run it @ 10 degrees. Former comp had clip down and I believe it was set a little lower. I would start at 6 and slightly advance it till you find the smoothest engine operation. All being said-- if that guy installed a "HEI" distributor in your boat not knowing what he is doing, chances are your timing is way off. Regardless of weather you fix your distributor or get a new one, you have to get base timing right and make sure your firing order is correct. Also agree a good working tach always helps when tuning. Hope this helps.

[Moor]

i believe this is correct for your engine. You should have a standard, or left hand rotation engine.

http://i1165.photobucket.com/albums/q591/booredmcb/Ford351.jpg (http://s1165.photobucket.com/user/booredmcb/media/Ford351.jpg.html)

[chautauquasun]

Just a quick update. I ended up getting the carb rebuilt then replaced points and condenser and set the dwell and timing correctly for the engine. It is running beautifully....or it was. See my new thread. I need some more help.