Im trying to diagnose an engine problem in a 1996 SS, and so far ive been unsucessfull. Basically the car starts after a few attempts, will idle fine, and then has a very noticable lack of torque while driving. I had it diagnosed by Goodyear but they wanted about 400 more dollars to check the cylinder compression to isolate a dead cylinder. The computer reads random misfires, and when the car is revved to about 4500 it backfires. The distributor and spark plugs are like new, but most people seem to think that the distrubutor is causing my problems. The fuel pump also needs to be replaced (Goodyear wanted 900 dollars to do that). I also put in a new fuel pressure regulator with my friend after following his advice, but unfortunately it didn't have an impact on the bad starting issue or engine problems. Could this be a tuning issue, or do you think I will need to start to look for a new engine?

 

probly fuel pump, same symptoms mine had about a year ago. they want to charge so much because of the way its in there, when i was going to get mine replaced they said they had to drop the whole rear end wich is B.S. they wanted about 600, even that is high. i ended up cutting a hole above the fuel tank in the trunk and that allowed me to change the pump from the top, saves about 2 hours as well, just make sure you dont try to weld or make any sparks by the fuel pump for obvious reasons, i ended up fabing up a little door with hinges that i can just open and close so if i ever need to replace it again its accessable.

 

Get a fuel injection pressure gauge and check the fuel pressure and the fuel pressure regulator. Check to see that the pump is holding pressure under hard acceleration. However, multiple misfires is usually an indication that the Optispark is sick. Do not bother just changing cap and rotor as the problem is usually in the electronics inside the case, especially if the Opti got wet. If you change the Opti, change the whole thing. You may also want to try a known good ignition coil, and ignition module. There is also a possibility that the timing chain jumped, but the only way to tell is to pull the timing cover.

Doing a compression test on this car is a real bear, and besides poor compression will not give a misfire indication on a scan tool. If you can find a good shop with an engine scope, they can look at the spark intensity and see if a cylinder is bad.

 

trap door dor the fuel pump? sounds like an interesting idea. where do you go to for parts? I was thinking of buying an msd distributor cap and rotor plus a fuel pump from summit.