garrett1021

Hey guys, I have been in an unfortunate situation where I can only get my car out once a month or so. The last time I went to start the car, it turned over and immediately backfired loudly before dying. I tried a handful of times and almost every time this exact situation played out. However, one time I got it to idle for ~5min. I thought I was successful in starting her up... until I pressed the gas. As soon as I gave it some gas it backfired and died.

I will say I have not done any work on the distributor in the past few years of ownership. Is this just indication I need new caps/rotors? I looked around and couldn't find someone who had this exact situation.

Any advice will help. Thanks guys!!!

fasterlaster

Pull the distributor caps and see if the one off center from the drive turns freely. It could be as simple as a broken internal distributor belt.

garrett1021

I pulled the caps and they do NOT freely rotate. Broken belt is out of the question

renn-boxer

I had a similar problem with my 91c4, same thing after sitting for about 45 days. It was a failed coil that caused the problem, My understanding is you can not just disconnect one coil to find the faulty one thou, as this can cause damage. Do some research before proceeding and best of luck.

garrett1021

Ah this is a great lead. Thanks!!!!

JasonAndreas

How?

wallra

you can just swap coils to find the bad one. what I mean is see If the car will run with one ignition module unplugged the try the other. It will run on 6 plugs.

jwbavalon

After checking the distributor belt, wiggle the intake manifold on both sides. If it freely moves, check the clamps on the rubber sleeves. If the sleeve is loose or off, it will cause an air leak and possible backfire.

wallra

yes

garrett1021

Thanks guys

Tonight I will unplug an ignition module and test the car starting on one coil, and then swap and see if it starts on the other coil. I will also try the permutations of the ignition modules with coils to see if it might be the wires.

I have also seen (after some research) that it could also be something with the spark plugs. If I don't identify a problem with the coils, or if both coils give faulty signals, I will most likely attempt a spark plug replacement and then do the coils afterward if the problem persists.

dlpalumbo

I recall reading about someone on this forum with same issue. Turned out to be fuel pressure regulator IIRC.

Good Luck

garrett1021

Okay guys I have a big update. I tried all of the different versions of coil and wire and found something interesting.

The rear ignition module wire, when plugged into either coil, allows the car to start and idle beautifully.
The front ignition module wire, when plugged into either coil, has the car backfiring and unable to start.

Here is my hypothesis: perhaps one or more of the spark plugs that are connected to the front ignition module are faulty. At first I thought that it may be the ignition module / wire itself, but I have yet to replace the spark plugs in the few years that I have owned the car.

What do you all think about this?

Thanks for the great leads everyone

964George

Could be a faultly cable, as in distributor to coil?
Try swapping the distributor to coil cables over (i.e. at both ends) and see if your issue jumps from the front to the rear module?
If so, it's that cable at fault.
If not then its either a spark plug or lead connected to that module as you're suspecting...

Good luck.

garrett1021

Do you have any idea how to do the distributor to coil test? You say swapping the cable over at both ends but I am not quite sure what you mean. I do not have quick access to the car or I would check for myself. Are you saying that there is just one wire that I need to swap at the distributor?

wallra

yes the wire that go's from the coil to the center on the distributor cap. try switching this wire