Hello all, My baby is idling rough, acceleration is gone, and has a funny smell to it (gas smell)....Ive replaced fuel filter,plugs and wires, both caps and rotors,all three exhaust gaskets, I even unplugged the maf sensor to see if it would change the way it ran!(ran the same) I have no check engine light on! Im stuck can someone help me out ,please...Thanks in advance Chris

 

gonna have to be a bit more specific for anyone to help you....


sorry to hear, i feel your pain. my sc400 was so problematic until i got the ECU rebuilt

 

Hey Chris,

I was having some hesitation problems on my 93 and today it started to affect the idle. I pulled the Idle Air Control Valve and cleaned it out real good. Undo the 3 phillips head screws and pull it out to inspect. There are 3 more screws on the underside and that will actually separate the stepper motor from the valve. Clean it up. Lube it up and roll the motor by hand a few times to make sure you have smooth operation. If your feeling real adventurous you can hook up battery power to the 2 center terminals on the connector and drag your ground wire across the other 4 connectors sequentially to make sure it is working. Good luck. Mine is working great now.

 

Here is a screenshot from the FSM on checking the IAC valve

 

you could also run a cleaner through like seafoam or sumtin along those lines that might help

 

I would try cleaning the idle speed valve first. If it is stuck wide open than you will have acceleration and idle issues. If that does not work than your next target is to check the throttle position sensor. You can run a cleaner through it, but I would check that valve first.

 

Well i took the idle control apart ,cleaned it, still running the same! I guess im gona replace the ignition coils next! (also ran some Seafoam throught the gas)

 

I hate to mention it, but one thing to consider is the caps in the ecu are possibly going bad. Hopefully not, but I thought it worth mentioning just in case.

 

i was wondering if u guys had a solution to this i havent cleaned anything yet i just purchased the car but my idle is around 300 -400 idk if this is normal and my car coming to a stop jolts back and forth like its gonna shut off let me know thanks guys