Is there a way to determine this for sure? I've been having a problem recently where the car will idle very very high (at about 2000RPM) and doesn't want to kickdown. It will eventually, but it's not consistent.

I hooked up the scanner to it and the IAC steps last night were at about 100 with the target steps supposed to be at 0. I have already removed the IAC and it was completely clean, so it's not a matter of it being gummed up. And the sensor is only about 10,000kms or less old. (replaced last year).

I unplugged the IAC while the engine is running and the idle speed did not change. So I hooked it up and again, it did not change. Does this mean the little motor is toast? I don't want to replace it if I'm not sure.

What else would cause a high idle?

 

Check out the TPS sensor on the thottle body. Could be one or the other.

 

Yeh, I thought of that too...but after some careful though, I decided there's not way it could be the TPS. If the TPS was faulty, it would either cause my car to run rich or lean and run like crap because of it, but the TPS does not govern the idle speed though. And the car runs fine too.

 

i know nothing about TPI systems like this, but i just thought i would add this: just because something is new or relatively new in this case, doesnt mean it cant go bad. granted the chances that it is the new part that has gone bad should be less than the chances the other older parts on the IAC have gone bad, but still it is possible.

 

IAC and TPS goes hand in hand..The only way the TPS would be accurate is if minimum idle is set correctly.Check the voltage of the TPS t idle and WOT..Also check if the voltage gradually increases with the throttle.This is of course assuming that the pintle setting of the IAC is up to specs...

Daz

 

Brad: You are correct...just because it's newer definately doesn't it works. I just like to leave that as a last resort.

Daz: The voltage on the TPS was at .71 when I first hooked up the laptop while the high idle problem was occuring. When the idle eventually started to drop, the TPS went back to .57 and I could see the IAC steps start to drop. At WOT, the TPS voltage reads 4.43 +/- .02. The voltage appears to be fairly linear, with no real spikes at all. The TPS is fastened on securely...wiggle it and the voltage reading doesn't change. And also, while the fast idle is occuring, the throttle blades are in the fully closed position. Does that give you any clues/thoughts/comments at all?

 

Coolant temperature sensor maybe? I'm not sure if that plays a role in warmup or not. I'm also not sure if the guage and actual sensor(s)/probe are one or diff. Just a thought...

Also really sounds like it could be a vacuum leak still.

 

.71 is at the very edge of it throwing a code. I think the pinle needs adjusting as the ECM is compensating for the too high RPM at idle..Just curios where is the timing set at(brown wire off)..?Sometimes the blade has to be open a tad for it to run better in the cold.First thing I would do is set back the TPS and redo the minimum air setting..assuming the timing is at a perfect stock setting

Daz

 

I don't have a timing gun so I'll have to get someone to help with that, but what would the proper reading be?

 

it should be what it says on the sticker..6 degrees?Unless you have an aftermarket chip,in which you have go by the chip manufacturers specification.

Daz