87 350 TBI guys help!!!

[jared87350]

my ignition control mod keeps going out.
its becoming a pain.
what could be the prob???

thanks

[D13]

1. Check your ground cables and the wires going to the module. It is not uncommon for thse wires to crack / break /short which can shorten the life of a module.
2.Replace your plug wires. If one is bad it will pulse back and eventually short out your module.
3. If you have a repeat problem use ONLY GM / Delco modules. Aftermarket ones are cheaper primarily because they delete the over voltage protection circuits.

My 1990, I put a set of Accel wires on it, it then ate a module and a coil every 20k miles until I put a set of Delco factory wires on, and a Delco module. 50k miles with no more issues.

[jared87350]

thanks for the advice.

[jared87350]

could it passibly be the ignition coil?
could a bad coil stop the whole ignition curcuit?
including the injectors?

[wyattglock]

It could be an ignition coil. I have a similar problem with my 454 tbi. I have replaced the plugs, wires, and ignition module. That seemed to help a lot. I tried swapping my friends coil from his 87 Jimmy onto my truck and that smoothed it out all together. So this week I am going to replace the coil and go from there.

[hugger6933]

GM had a recall on the 87's becasue of a dist oil problem. the oil wick in the shaft had some design flaws [best I can remember]. Not to overlook anything simple you are putting the grease under the module? I have always been told that will lend to overheating problems. Jim

[jared87350]

i replaced the ignition mod today and put the white grease under it.
having the same problem. no start. the injectors are not pulsating eather.
i replaced the igniton mod yesterday as well and seamed to fix the problem; then on the freeway it dies with no symptom leading up to it.
it has to be something that is tying the injectors with the ignition.
all powers and ground have been look over. unless somehow i missed one or two.

if its not the ignition mod being bad; what could it be?
any advice would be great.

i am out of ideas .all sensors have been replaced as with the ECM.
this problem seeme to be off and on recently; now it just dosnt start.

[D13]

Injection is based on seeing ignition pulse. No pulse, no signal to ECM, no injection.

Pick up coil in the distributor? If you have a AC voltmeter, unplug the pickup coil from the module and watch for AC voltage on the coil as you crank. If the coil isn't producing voltage the module doesn't produce a signal.

[Big Port Jimmy 6]

I had a TB 350 in my 72 for a while, It started to eat the modules and I replaced the distributor and it stopped for at least 25k more miles until I traded the truck off. Jay

[jared87350]

bump for help

[jared87350]

can a bad spark control mod cause a no start??

[rfmaster]

Originally Posted by jared87350

can a bad spark control mod cause a no start??

Yes, it can - especially with after market coils. In your case I would strongly recommend replacing reluctor coil (or getting rebuilt distributor all together). Reluctor coil picks-up magnetic flux variation induced by rotor cage. I have seen magnets go bad with age (loosing magnetism due to repeated heat cycling). Since relucotor coil supplies pulses to ignition control module (ICM) your troubles may appear as ICM failure when the real problem is with reluctor coil or rotor wheel. It is worth a check - check coil resistance - it should be between 500 and 1200 Ohms.

//RF