Help with electronic ignition conversion 88 comp asap!!

[Cassiedee]

I have a 1988 Supra Comp. Called Skidim and received the conversion kit. Installed today. Engine has a miss at idle. Any ideas? My boyfriend is a mechanic and has checked everything. I was told the standard coil would work. Is this the problem? Two weeks no boat please help!!

[michael hunter]

Try putting the points back in and see if it cures the miss.

[Loadup]

Michael is the man with stuff like this. He helped me resolve problems with mine. curious, when you say conversion kit, is it the tune up stuff or the new distributer ?

[lively]

I have a 1988 Supra Comp. Called Skidim and received the conversion kit. Installed today. Engine has a miss at idle. Any ideas? My boyfriend is a mechanic and has checked everything. I was told the standard coil would work. Is this the problem? Two weeks no boat please help!!coil is not going to cause this missfire ... All the coil needs is 8v when starting and running through the stock ballast resistor .. did you purchase the mallory conversion ? im guessing this is a 351 w ?
*misfire could be wire arching against plugs (check all wires and make sure they are seating firmly into plug) "quick way to tell if it is a actual MISFIRE from the spark plug , start pulling one wire off the dizzy cap and see if the motor changes. do this until you get to the one that does not change that is where the misfire will be. simple and you need no tools :) hope you get it . and if you dont , report back

[CornRickey]

please post the brand. with Petronix you need to eliminate the ballast resistor and get a coil with the proper resistance. they are touchy with volts but usually the issue with wrong volts it's difficult starting. Regardless call the manufacture tech support. Petronix is great.

[92SupraComp]

did you have the coil packs then converted? or the points replacement?

[cadunkle]

Is this a Pertronix points replacement? If so ensure it is getting full +12v key on. You will use power at the battery/ignition switch side of the ballast resistor to power the Pertronix (or any other points replacement unit that I know of).

The coil may or may not require a ballast resistor. If it's the original coil and was wired through the ballast resistor leave it that way. Typically a coil will be labeled "ballast resistor required" or similar if it requires less than 12 volts. If not labeled as such give it full key on +12v. If in doubt you can try it with full +12v and will get a hotter spark but the coil will overheat and fail if it does require a ballast resistor. Fine to test like that though.

If Pertronix, verify the air gap between the piece that slips over the points cam with the magnets, and the pickup module. I believe it was .030". Should be stated in the instructions though.

Ensure you set the initial timing after installing the Pertronix. Anywhere in the 6* to 10* range is good and should be safe, though if you hear detonation you may need to back off a couple degrees or use higher octane fuel.

[CornRickey]

my Petronix gap wasn't adjustable

[cadunkle]

What is the gap set to? What about the rest of what I mentioned? If you want help please specify details of how everything is currently set up, voltages, wiring, timing, etc. If you don't specify all this and continue with one liners nobody here can help you. So details, or I'm through with this thread. If you can't or won't provide the details we ask for then go find a mechanic and pay him to fix it for you.

[Salty87]

somebody has a case of the wednesdays...CornRickey isn't the OP.

and, since the OP seems to have left the Pertronix thread I'll veer it off course a little bit.

i took my points out to install a pertronix but the post that the points sit on is in the way. summit racing says i have the correct pertronix for my distributor. did you guys have to remove that post or was there a cutout in the mounting plate of the pertronix?

[Blackntan90]

Salty, when I installed my Pertronix it was on a Prestolite distributor and I do not recall a post being in the way. You may want to give skidim a call.

[michael hunter]

I won a electronic conversion from PCM it came as a complete unit base plate and all . When it failed after 5 minutes of run time I put the points still on the plate back on . PCM replaced the faulty unit but I never installed the electronic again.

[Cassiedee]

I used the wrong word previously-the engine was loping at idle-it was not a miss. Item #13212 "breakerless ignition kit" from Skidim. They told me the stock coil would be okay. After a couple hours of trial and error, we discovered the connector's on the supplied wire harness were not making a good connection-we had to squeeze the connector's hard for them to snap together and work correctly. Started the boat right up and it ran great!! Now, after a thorough warm up, it has a hard start and will not idle at all but will run if you can get it going. But, it seems to load up or run rich. Any idea's? We are thinking the coil needs replaced or the choke is closing.

[michael hunter]

Sounds like a blown power valve or floats adjusted too high. When was the carb overhauled last?

[chris young]

So I just spent the weekend adjusting the floats and idle mixture and timing etc and discovered many things that I think may be related to the EFI conversion done before I bought the boat,(Crane XR700)

Firstly, I've been chasing what I thought was a slipping transmission which is very likely a tach reading high. I haven't confirmed it yet but a quick look at the installation instructions for the unit references this issue, so that may be saving me a transmission OH.

Next, very hard start.. I've ordered a new key switch because I've noticed that it would crank without a hint of firing and then fire when you let go of the start. It seemed to start much better when I shorted the solenoid contacts with the ignition on. Unfortunately I couldn't see the EFI troubleshooting LED and turn the key at the same time, but it seems pretty sure that the key switch may be faulty.

And finally, the timing was adjusted to around 30 deg BTC and when I tried to adjust it to the proper 6 deg, it would barely run, so I'm at a loss as to what's up there. I'll have to pull the #1 plug and find TDC on my own unless someone knows what's going on here.

[chris young]

So I've done a bunch of research, and my issues may be more than one. I've got a new key switch, I'll put that in, but I will also measure the voltage at the coil during start. I need to re assess how the optical pickup was installed, as well as the fly weights and springs.

I'm going to find TDC using the piston stop method (most accurate) and mark the harmonic balancer. It is possible that the elastomer has let go and it's moving. If so, then I'll need a new one in the spring. If it's right where it is supposed to be (TDC) then the only thing left is ignition wiring in the wrong spot. Lucky for us the firing order is stamped right on the engine ID tag. I'm also going to use my DMM with frequency counter to check the rpm of the engine, (don't know if it'll work or not) I'm pretty sure the Tach is way out.

I'll keep everyone posted as to my results. These older motors are so easy to work on, and sitting in the boat at the dock is the right way to do maintenance;)

[CornRickey]

my SN did what you subscribed ( won't fire until you let off the key then it would). Thishappened after my elect. ignition conversion. Turns out with mine that the unit wasn't getting enough volts while cranking due to a weak starter pulling to many amps stealing from the ignition. When the starter would disengage the ignition would trigger and made the engine pop. sometimes it would stay running, sometimes it wouldn't. I troubleshooted the issue by running a hot wire from the solenoid ( hot when the solenoid it triggered) to my coil and the hard start issue disappeared.

[chris young]

Interesting, it seems that that is the way most ignitions are supposed to be wired but I've found PCM351 wiring diagrams that show your hot wire and some that don't. In my case I don't know if it's there or not but it will be for sure. With the Crane XR700 you need to leave the ballast resistor in, so the hot wire is even more important for good spark on the start.

Mine has a newly rebuilt starter, but a mediocre battery, but for sure it'll get some voltage tests and a new ignition switch. I'm keen to get back to the boat to do this work, plus I'm going to look into my tach issue as well. Apparently the electronic ignition can cause tach issues as well.