I found out via replacing everything that if the Opti signal is inconcise you'll get VERY odd behavior. I see we're up to about post 151 on this topic. If you haven't already, clean and examine every Opti/spark related connector to make sure they get good consistent connection. One time, I introduced an issue by looking for another by sticking a probe into the ICM (Ignition Control Module) connector and inadvertantly pried the female opening too wide. Not realizing this, I just plugged it back in. After I discovered and repaired the original problem, it still wouldn't start. I started my diagnostics again and when I started looking at the ICM connector, I decided to test the volts when it was connected. I stuck a straight pin(like comes on new dress shirts) into the backside of the connectors wire openings. Backprobing. I hooked up my volt meter to the pin and a chassis ground and had my assistant crank the car. What I found was that when I pushed the pin firmly into the connector, the car started but as soon as I stopped pushing the pin into the connector(thus breaking contact with the internal pin) the car died. I pulled the connector off and looked at it and I could just barely discern that one opening was bigger than the other 3. I took my pin pointed continuity probe and gently pried the opening back like the others, reconnected it and it started perfectly after that. Later on, another guy from this forum posted he had a similar problem. I gave him this account of what I'd ran into and my fix. He looked at his and that was his problem as well. I hope yours is something similarly simple.

 

Well he is mostly convinced that its not the opti. 1 because the car ran perfect for a week before it started in again with the starting prob, the only thing we did is put fuel in and it took a turn for the worse. 2. because it will run on starting fluid and 3 because it was running with 2 of the injectors unplugged.

I am not trying to side step around the opti because we have had an opti prob in the past and it was replaced. Thanks for everyones help it is much appreciated.

We are trying to figure out if its ECM or something else much easier like a sensor.

 

ok. Be sure to post what you found that resolves this. If you do a search on posts started by me, you'll see the enormous trouble I went to trying to resolve a very similar problem. In a nutshell, I spent around $1,000.00 in parts, disassembled tons of things, only to find in the end it was wiring in the ignition circuit. The condition caused it to spark very erratically, and by extension, the fuel injectors. The PCM would say it was extremely lean but the plugs were soaking wet with gas. I posted what I found eventually. So many guys start a thread and after much back and forth, they either die or just don't feel like posting anymore.

 

I will let you know I think we are down to taking it over to another guy who did a better diag on it then the last guy. My thoughts are spend 60 bucks for him to tell us what is wrong vs. spending 60 bucks here and there for new sensors or bunches more for the computer only to find out thats not it. I have over 500 in it now.

 

I know what you mean. After buying 2 new O2 Sensors, 1 new opti, 1 new opti pigtail, 1 new wiring harness, 3 sets of plugs, 2 sets of plug wires, borrowing a friends set of injectors, borrowing a friends coils(I had the LTCC setup), pulling off the timing cover and verifying the cam was installed correctly, NOID light, various tools, Fuel Pressure regulator, new ICM, new LT1 coil, I found it was just some kind of wiring issue with the LTCC. It was sparking all over the place and running the Fuel Injectors too much because the Opti was 'confused' by the signals it was reading.

 

Still nothing yet. New MAP, New plugs still turns over...give it a shot of starting fluid and it will fire but then its impossible to keep running. TPS and O2 sensor next on list. Will keep you updated.

 

Grrrr... man. Your luck sounds too much like mine.
I have all kinds of extra/spare parts now. Lol...

 

Just wanted to check in and say we have not done anything else since replacing the spark plugs. We did some work to our Jimmy (ball joints upper and lower) because we are stumped on the car. LOL This week is rent week and we are going camping over the weekend so it might be another week before we get back to it. I just didn't want you all think I didn't come back with a solution because we have not found one yet.

 

Cool. Thanks for the update. I know it's frustrating. Glad to see you're not giving up

 

so have you cked fuel pressure? (sorry if i missed it in reading all the post)

 

yep it sucked and we put a new fuel pump in and it has good pressure.

 

ok we got a OBD 1 & 2 XRay 2000 and they are telling me they don't support my engine. After the dude told us it would work. Grrr anyone know anything about them not supporting the engine?? So i guess we wasted our time and money with that. Thats ok he was going to use it for his truck also and it doesn't work on it. both are 94 and he said whats up with that? Just thought I would pop in for a quick update. He put the ECM back in the car and it started. Lots of white blueish smoke. Then died and went back to just turning over and not starting. UGH...just my luck.

 

Yeah for OBDI, there's hardly anything that works as far as a scanner. If you had a cable, you could use it with LT1 edit to scan the car and see what it's doing.

 

What is LT1? different then OBD2? I guess I don't understand what you meant. Sorry...

 

LT1 is the motor in your car. GenII Small Block Chevy. LT1 edit is software to reprogram your cars computer and has a scanner included in the software.