dsky

replaced optispark,wires,plugs,water pump, watertemp sensor, both o2 sensors. check for fuel pressure,42 before enginne on 39 after.
egr valve is free and when i apply vacume ,it acuates.

problem , i get pinging under accell and the idle gets rougher as the engine temp rises.
at this point the engine will stall at a stop light, but starts imediatly.

i brought it to the chev dealer, i ask em to tell me whats wrong. they have it a day and a half and tell me its foulded plugs.

get the car home and remove plugs, they are clean as can be. (new bosche platinum)

what gives here guys, i need your help.

LouisBarton

The dealer told me that the ECM needs to relearn sensor values after some, but not all parts changes. It sounds like the ECM thinks its getting a too rich signal and trying to lean things out. Or more probably, it is not sending correct distributor timing signals. There is a section on this in the 92 chevy service manual that is complete but very dense reading.