850 GLT Idle RPM

oughorian · Post by **oughorian** » 13 Feb 2011, 22:44

Hi everyone. since I bought my 1996 850 GLT I had and have Idle problem with my car. I know the idle rpm should be around 850 rpm but it's stays at 1000. The car runs good, no air leak, replaced idle control valve, clean throttle body and MAF but so far no changes on idle condition. Turning the AC on have no effect at idle speed . Idle rpm is steady no up and down, recent cold temp. in LA had very little effect on cold morning first start, about 1050 or 1100 rpm. Let me know please if anybody has suggestion or idea about this? Thank you all.
Art.

Post by **jblackburn** » 13 Feb 2011, 23:00

Keep in mind the tachometer isn't 100% accurate. My S70 shows around 875 on an OBDII scan tool, but the dash needle looks like it's just between the 900 and 1000 marks. I would confirm that before anything - ask an auto parts store if they can connect to your OBDII port (under your coin tray) and read off the idle speed to you.

If it still shows high there, does your temperature gauge ever fall as you are driving around at different speeds? A bad ECT sensor could cause something like that, as could a slightly out of adjustment throttle cable or gummed up idle control valve/throttle body. Lots of possibilities, so start with the simplest first and confirm that it is actually idling high!