jbuck_atlanta

I have an '89 Camaro RS 305 TBI with 700r4. My car has about a 50/50 chance of shutting off when I shift it into reverse or drive unless I give it some gas and it also shuts off when I'm in gear at a stop after the car warms up. I thought it was an electrical problem because it would misfire, pulse and vibrate sometimes so I replaced my Ignition control module (put the grease underneath), distributor cap, throttle position sensor, idle air control valve, spark plug wires, spark plugs, ignition coil and cleaned out the carb but it has not changed the way the car acts at all. I was very surprised by this because many of the parts I replaced looked to be in horrible condition especially the spark plugs but I was wrong. It still has random pulses, vibrations, and misfires at a stop and still shuts off. At this point, I'm thinking that the fuel pump is going out but won't all out quit yet but I'm not sure. It may be original and the car has about 170k miles on it. Does anyone have an opinion on this or ways to figure out what's wrong?

jbuck_atlanta

also on another note are there any other grounds for the ICM besides the distributor plate itself?

ASE doc

Wow. That'll a pretty good list of parts to throw at a problem. Some of those parts aren't even among what I would consider likely causes for the symptoms you describe. I don't mean to beat up on you but with any runnability fault, you have to start by at least trying to pinpoint the cause. Otherwise, you can replace every part on the car and not solve a problem caused by old faulty wiring.
You replaced the ignition module. I assume the dist is OE. So you put a new module in a 30 year old distributor that could easily have a failing pick up coil. I would have recommended replacing the complete unit with a brand new one from Delphi. The ICM grounds to the dist through the screws.

The random misfire you describe sounds like an ignition fault but could also be a lean or rich condition. Does the car climb hills okay? No lack of power? If so, the fuel pump isn't your problem. In any case of stalling or misfire at idle, the pump is probably not the cause as there is very little fuel demand. Take the air cleaner off and with the engine idling look at the injector spray in the throttle body. It should be a decent cone shape that just about covers the throttle blades. Now, snap the throttle. The fuel spray should surge so that the spray fills the bores.
If this all looks like I describe , the pump, regulator and injectors are okay.

Get a scan tool that works on GM OBD I. Use it to look at INT and BLM. They should both be around 128. Make sure the O2 sensor voltage toggles once the engine is warmed up. Check for codes.

Report back.

ASE doc

Take a closer look at the dist. Look at the pole piece and timing core. If they are very rusty, replace the distributor. If the was at my shop, i would put it on the scope and look for ignition faults or uneven combustion. Check the pick up coil with an ohm meter. It should read between 800 to 1100 ohms.

jbuck_atlanta

Yeah the distributor looks very rusty and is OE. Are there any temporary fixes like adding a couple grounds until I get a new one? Is this a job I can do myself?