ROUGH IDLE

[joseandmarilyn]

When I first start my car it has a rough idle, but after a bit it stops, but sometimes when im driving and shifting from 1st gear to 2nd it feels its going to shut off and even though I hit the gas it wont go nowhere, it all quits right away. I thought it was my MAP sensor I changed it but it still does it. CAN SOMEBODY PLEASE HELP ME AND AT LEAST GUIDE ME ON WHAT TO DO NEXT.

[silverstangboy]

do the KOEO test and the KOER test...

I wouldn't consider replacing any other sensors until that is done.
DIY KOEO/KOER/Cylinder Balance Self-Test Procedure

sorry for linking to another site brent, but joel is the man.

[bullitt482]

Check the MAF also... Could be REALLY dirty.

[joseandmarilyn]

I already replaced the MAF,Fuel Filter,MAP, and the car still does it I think it might just be my fuel pump or injectors, because when its on idle and i verly tap the gas it backfires so it might be my fuel pump or injectors.
IF ANYBODY OF YOU GUYS THINK ITS SOMETHING ELSE CAN YOU HELP ME...
THANKS

[MonteCitan]

if it backfires, it could be either timing or fuel...

Might need the ignition module, or could have an injector stuck open.. could even be a bad vacuum leak or bad evap issue.. check the codes asap... not that they're very accurate in EEC IV

[silverstangboy]

codes first, check MAF second... BTW a bad maf will usually show up in the memory.

[svtlx]

i'm lean'n towards fuel pump. put a gauge on the schrader valve. if u have to, keep it in the car and check it when the car starts act'n up. some pumps don't start act'n up till their warmed up. just a thought.

[BADLX5.0]

i would check the adjustment of the tps sensor, or the iac valve, mine had the same problem, got the specs from alldata on the tps sensor, and cleaned out the iac and it idles smooth

[squirt]

If its the same car as the wont start post---the 4 Cyl. that has the timing belt broken then I woulod recheck to make sure your timing-belt marks are right.....just my two cents.