McAllenSuperSport

My cousin our friend and I replaced my cousin's Opti-Spark and water pump yesterday and it started fine last night.. Today car started fine when he left to work... While he was driving to work his car all of a sudden turned off.. he pushed it to the side of the road and tried starting it a few times.. It started after about five minutes of waiting to keep the starting from overheating and it started. The tach was going crazy, rpms where jumping from 0 to 1000 etc.. We cant figure out how to fix this problem. We plan on hooking up a scanner too see why the SES light is on... I know there are a lot of vaccum lines that are disconnected but I don't know if that will affect the starting/no spark problem... Your solutions and ideas would be most appreciated.. Thanks. Chris.

SpeedDensityZ

iTrader: (5)

Maybe the ICM, do you have strong spark while cranking?? Get a repair manual it has a step by step troubleshooting guide.

ss.slp.ls1

iTrader: (36)

Get rid of the vacuum leaks, get the car scanned and then get back to us.

McAllenSuperSport

Still No spark while cranking... That was the reason we swapped out the old Opti-Spark.. It needed it anyways, the terminals on the cap where caked and was rusted to hell.. We have the repair manual.. We went over everything still cant figure it out.. Once we get the scanner on, I'll definietly let you all know what it reads.. Thanks for the fast reply!!

ss.slp.ls1

iTrader: (36)

Undo the coil wire from the opti and test for spark at the coil.

SpeedDensityZ

iTrader: (5)

Yep, if you don't have spark there I'm willing to bet it's the ICM.

McAllenSuperSport

Well some SOB broke in to my cousin's Trans Am so, We'll have to wait until we fix the window in order to diagnose the no start problem... He was to pist to work on it.. I would have been too. They stole his CD Deck... I notice when he started it, it turned on but about 2 seconds later, it shut off. The RPM gauge would move up and down from 0rpms to 7000rpms while the car was off. You could also hear the fuel pump humming from a high pitch sound to a low pitch sound... My cousin thinks the computer is fried..

litch2004

iTrader: (1)

mine has done this 2 different times. The first time it did it it was my opti. The second time it did it it was the computer. So good luck to him. Hope he figured it out.

McAllenSuperSport

We changed the ICM and still, it doesn't turn on.. We checked the pcm harness for tears and cuts and everything looked good. I believe my cousin is going to inspect and test the computer to see if it has a certain amount of ohms or some ****..

McAllenSuperSport

well we tested the harness from the opti to the pcm and the numbers didn't match... We where checking the spark plug wires to make sure they where tight. The ignition wires where in the way and when we went to move them, the fans started to turn on and the injectors where clicking.. I believe there is a short in the engine harness. Would it be a pain to replace the harness?? And where could I find one? The Car will start but it tends to die, It also missfire and backfires and will shut off..

ss.slp.ls1

iTrader: (36)

Check the grounds to the coil (there are three of them). Also check the ground from the coil to the chassis.

Swapping the wire harness isn't too bad of a job. You can get it done in under an hour if you know where everything goes. Look in the Classifieds section for a new harness. Try to match your year.