Ignition coils going out?

[TajMan]

My '93 Stealth TT, I can't hardly get it to idle anymore.. I mean I can't get it to idle and I can hardly get the engine to rev up with throttle! seems like cylinders aren't getting spark.. has seemed an intermittent problem possibly ignition coils dying/bad connection.

Earlier, sometimes when started it was just missing a little bit like that, but after 30 seconds it would go back to normal and engine running smooth.
Now, problem has gotten worse and seems to be stuck that way.

I bought this modded car from 3si member and have never had it 100% good on the road yet.
I just installed AEM afpr but I'm not seeing pressure as high as it should be able to go, I'll look at the fuel pump next maybe its stock and not a upgrade already like I was told.

Supposedly car is on 550 injectors, but I do have 6 stock DSM bluetop 450's I was going to get cleaned/flow tested and I could possibly use those.
Has innovative wideband, SAFC II.

The car is a '93 with no CAS, how do you adjust ignition timing on a 2G motor? I have a lightweight underdrive crank pulley to install, but they have no timing mark to set base timing on a 1G right?

How much are new ignition coil packs again (there are 3 right)? Or should I swap them with a buddy's VR-4 to see if it fixes my 1 issue? difference between years?

[Greg E]

Lots of guessing and costly checking. Seems like you're heading in the direction of a spark issue, but the root cause is right in front of you.

Even a stock fuel pump should get you adequate fuel pressure at idle. If your fuel filter, injectors or pump are gummed up, that will definitely cause the issues you're seeing. Typically from particles of rusty gas tanks.

I'd start by reinstalling the stock FPR and injectors then replace the fuel filter while keeping your pressure gauge installed (if you can).

[75blackray]

Coil packs are $130 for the set from IPS
Mitsubishi 3000GT / Stealth Ignition Coils - Coils - Ignition - Turbo - 3000GT / Stealth

I was having a similar issue of the car missing occasionally at idle and then breaking up badly at around 5k at WOT. I just replaced the coils, haven't been on the road yet, but no more missing at idle so far. Either way replacing the coils on a 20 year old car is never a bad idea for under $150.

[mike3000gtx2]

I had a similar issue turned out to be my ignition control module, i had 2 cylinders getting weak spark and 2 getting none at all. the module can be tested using a D-Battery and ohmeter.

[TajMan]

Thanks, awesome.
Going back to stock stuff isn't going to be a real option, definitely not back to stock fpr..

I will test the ignition control module, and check what fuel pump is in there, and most likely just replace the coil packs.

I haven't even begun to fix the real problem yet, when the engine seemed to be running better before, in which the tune was not right and acting crazy on the wideband - alternating from running closer to running way further off in a way that seemed totally random not relating to how I was driving.. and adjustments on the SAFCII didn't seem to have the desired/predictable effects on the tune..

[vroom4]

I think your best bet is to go back to stock fuel system and zero out the safc first...cheap parts usually.

[Greg E]

No need to blow $$ on coils if yours are already good. Testing them is very easy. Just grab a volt meter, stick both prongs into the coil leads and measure the resistance.