[88stdsdn]

My mechanic did a major tune up using OEM parts. But the problem is the idle stays around 1000rpm, and not at the normal 680-750rpm. Sometimes it stays at the normal range and sometimes it doesn't. Engine temperature and outside temperature doesn't seem to affect idle. The engine at idle is rougher and vibrates more than it did before the tune up. There are no ECU error codes, red or yellow. My mechanic tried to solve the problem by lowering the idle screw, but that didn't do anything. The idle would just vary from 500rpm to 1000rpm, as opposed to normal to 1000rpm. And the yellow light on the ECU would light up, telling me that the idle is too low. I turned the screw so that the yellow light would go away, but either way the problem is still there. Any ideas? Thanks.

Major Tune Up Work Included-All parts purchased at dealer
NGK Spark Plugs
Spark Plug Wires (Sumitomo)
Fuel Filter
Air Filter
Distributor Cap
Distributor Rotor
Coolant Flush

 

[paulo57509]

Occasionally, the idle in my car will mysteriously become slow to return to its "normal" set speed. It would hover around 1000 rpm, then slowly return to normal. No codes, nothing obviuosly wrong anywhere.

Looking trough the reams of service invoices that came with the car, revealed that this has been complaint on a few occasions. The fix?

Remove the ALT SENSE fuse (reset the ECU) and the problem goes away.

Try resetting the ECU, and then readjust the idle speed. Your mechanic didn't mess with the throttle blade stop screw, did he/she?

 

[saimerej]

When you had the tune up the mech's probably adjusted your throttle control assembly to a higher tuning. I did this a couple of weeks ago, when I noticed that my car would try to die if I was sitting still and turned my steering wheel. It's a fairly simple thing to fix. I personally wouldn't worry about it. I tend to think that the mech's know best. If you want to adjust it though it's just a matter of adjusting a couple of lock nuts.