omatter67

title Hey everyone,

I have a 1993 lt1 formula with 130,000 MIL and I ran into a problem with Hesitation along with jumpy rpms followed by some bucking. I replaced the F/P regulator the cap and rotor and still have the problem. I read some MSGS about the opti but I'm not too educated on it, can someone give me there diagnosis, I'm being told to replace the distributor. Any insite will be Appreciated.

Mat

slopokrodrigez

At this point in the life of the engine, it would also be advisable to check either compression or leak down before you go through all the other stuff since a valve problem can give you drivability issues.

It's also a good idea to check the cat to see if it's clogged which occurs easily and often. The pro way is to put a back pressure gage in the O2 bung. The cheap way is disconnect the cat and test drive it.

Provided the above is good, then the only thing you haven't accounted for with the distributor is the optical sensors and their feed back signals to the PCM (both high and low resolution). It's doubtful these signals are corrupt. My suggestion would be to do a complete tuneup from Ato Z on anything you haven't done yet. Plugs, wires, map sensor, O2s, clean the IAC, EGR, TB and last, have the injectors cleaned professionally. You may also want a new coil and ICM.

Injuneer

Have you checked for any codes? Easy to do on a 93, using a paper clip. If you had optical sensor problems, you would have DTC 16 and/or 36.