My 92 3.1rs runs rough and Sluggish. have replaced all the sensors as well as the ECM. Have replaced IAC,TPS,MAP,O2,ECM,Dist cap and button as well as est,coil pack,Spark plugs,Spark plug wires,fuel filter,temp sensor for ECM and K&N air filter. all was done at the same time. not even a week ago..still runs rough and sluggish as if the motor is tired...when i first start the car for the day it starts perfect and then begins to run rough..every second or two it tries to clear up to a smooth and perfect idle as it should be but then drops again to rough. The engine never tries to stall. also the fuel pump is less than a year old, muffler is new and has no cat on it. I have no SES light..and i have had a diagnostic test done and all says aok even my smog test passed....but something make the car run rough and slow.i have cleared all possible passed ses codes in the ecm by disconnection the battery. All is the same. HELPPPP lossin my da** mind!!! Any one have the same prob before??!!
Thanks, GoldenDrako

 

Check the ground for engine block to the chasis. You need the least amount of resistance possible.

How about your timing. What is it set at? I am sure you replaced the TPS but did you check it with a multimeter and adjust it if it needs it?

 

Yes I set the timing it's at stock timing i believe 10degrees. and to the TPS i have not checked with a multimeter..so how to check that?I have checked the ground from block to chasis and seems fine but will check again..the rough idle was present even before i changed any parts...that is the reason for all of this fun and headaches

 

This may help.

https://www.thirdgen.org/tpimod2