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??!! Oh i tested the fuel pressure..it's at 9psi with the key to prime the pump and about 37psi while it runs..
Thanks, GoldenDrako

 

vacuum leak, fuel injectors, EGR.. etc etc

I heard vacuum leak can lead to whole sort of problems..

 

Hmmm,

What about water in the gas???? or plugged injectors???

(I run 39psi @ idle),

Denis V.

 

I've had two cases like this...

My '86 5.0 TPI had 2 nearly dead injectors.

My '90 3.1 had a bad ECM, it tested ok and all sensor inputs
looked great - but it never would go into closed loop.

sixgun (jjr)