I have been working on my brothers 1987 Chevy Cavalier 2.0 RS for over 3 months, not constant, though. Ran fine one day, went to go to work the next and it wouldn't start. It was suggested by others to replace the coil packs, so we did. That did not solve the problem. I have checked all spark plugs with a testing light, they seem to be fine. I pulled a TBI unit from a junkyard in hopes of swapping out all the parts and pieces and trying to get it to work. I went through all of the testing procedures i could find around the internet. At some point i tried to pull trouble codes with a jumper from 6 to 12, and 5 to 6, 5 to 6 seemed to run the Blower motor, and there doesn't seem to be a check engine light anywhere on/in the dash anyway.... It's getting Spark, it's turning over, and the injector is spraying fuel... It seemed to me that it was the Engine Control Computer, So i replaced it as well, Cranked strong but no start. Re-used the PROM - dont know if that could be an issue. I have been reading from all the sources i can find and spending what time i can messing with it, could really use some assistance with this. I have Access to voltage meters and others things, i just need a next step, or even a past step repeated. Maybe ideas from the top so i can eliminate them one at a time. I only recently started messing cars/trucks so, im kind of a newbie. Any other info anyone might need, let me know. Thanks in advance for any assistance.

 

Pshhh, X body. What color is the spark? Probably fuel, give a little more history, when what? You need to also look for vacuum leaks with a vehicle of that age, again, more history will help to diagnose.

 

Well, i've been messing with it on and off over a kinda long period of time, as best i can recall the history of this vehicle. My brother got it from a guy, it had been sitting for greater than 5 years i think. Put a battery in it and drove it home, it needed work. It would idle really, really high, brought it to someone that "knew what they were doing" got it back running decent, perhaps good. (unsure what was done) Shortly after that, maybe 4 months in, it began running choppy/stalling, something i had read made me replace the fuel filter. was choppy at first but evened out and ran good. He then drove it daily for several years, right at 3-4. There probably wasnt much maintenance outside of oil changes. Then it just didn't start at all. Replaced coil packs first. Then swapped out the whole throttle body for a used one. That's pretty much it, it's been sitting now with me messing with it when i can for over 3 months, not sure exactly maybe upwards of 4-5. He had lost interest in it, bought a new one, it was just sitting and im trying to get it running for as cheaply as possible at this point. As for the color spark, it's been right at a month since i messed with it the last time, and i don't know the color of spark, a friend was outside the car checking for spark as i turned it over, tell me what to look for and ill gladly do/re-do the tests/diagnostics. Guess im going to go from the top and check for Coil pack orientation, wires, firing order, plug gaps/condition, color of spark, and will probably go through all the fuses again...if all that is good, could it be the fuel filter, even though the TBI is getting fuel? perhaps that would be next...let me know, Thanks.

 

Add some heet to the gas tank, and make sure you have fuel pressure. Spark should be white or bright blue, not orange.