The car idles at 800 in neutral, 700 in drive and reverse - but when I put the trans back in park the engine revs to 1500. ECU shows no trouble code (55). Any one have an idea of whats happening?.

 

Bad tranny computer? Does it start in park idling at 1500rpm?

 

1200 when cold - 1000 when hot. Any tests , that I can run on the tranny computer ?

 

Sticky throttle body? Try running some seafoam through it...I will be doing that myself once spring arrives...

 

Would have to consult FSM about tranny test. You can go to PhatG20.com and download a FSM for your car. Only owned 1 auto max so no personal experience. More I think about it, could be Idle Air control valve on intake (thing with screw on top to adjust idle).

 

I've got idle issues too and am planning on cleaning my TB asap.

Found this in the 4th gen forum but figure a lot of it can be applied to ours http://www.motorvate.ca/mvp.php/517

 

not to be rude or anything about jacking your post...but my car does the samething...when i start the car up the idle would stay above 1500..it would never do down...i knoe this is bad because my bro has a 92 se..and it only idles at 1000..(thats when the car is on park)..how do i make my idle stay below 1500..(sometimes it also stays higher then 1500..more like 2000-2500 rpm)..does anyone knoe how to fix this..i try tightening the throttle cable..and cleaning the throttle body..but still does the same thing...help...this is very annoying sometimes..any help would be appreciated..

 

Man!! I've own my max since 2004 and I thought this was normal (1200-1300 RPM at cold start), so what's the ideal idle RPM when in Park?? I hope someone have a good write up on this since I see that we are more than one person with this kind of issue

 

It is indeed normal ................ about 1 minute's worth of idling in summer will progressively bring idle speed down as the motor warms up to around 800-900 rpmAssuming the motor is at normal operating temperature - yes? ................ and the revs stay at that level? - yes? ................. and also assuming you are not touching the throttle during this time - yes?

If so, then the IACV-AAC valve ( and/or its controls) is to blame - it may be sticking/slow to respond to the ECU's electrical inputsCannot see how that will cause the symptoms given the above situation if its confirmed - other than sitting quite still during the whole process described it cannot have any influence on idling - and if it does it would have to have stuck slightly open and may actually fall back to its normal resting position (because of return spring action) actually causing the revs to drop if its position suddenly changed due to engine vibrationSorry - but if the TB is "dirty" I don't see how its going to cause a wonky idle as per the experience detailed here - the IACV valve (and its associated controls) is in control of the idling when you take your foot off the accelerator (and therefore have the throttle sitting static on its closed stop)

 

Yes, Yes and Yes. So will a cleaning of the IACV help or do I need to change the stepper motor. Can I just take out the motor and clean the valve ( will it slide out easily) or do I have to disconnect the cooling tubes and take apart the whole IACV.

 

If the IACV is the culprit ( as it would indeed seem because of its ability to regulate idle speed lower down) and dirt is the reason, then yes it will help.

I have never had to strip and clean the beast myself, so I will let others who have done so, detail the recipe and pitfalls.

Question begs why is it dirty/sticking given it sits after an air filter that you are supposed to keep clean and serviceable.?

 

For the same reason the throttle body/intake plenum gets dirty - oil from the pcv valve

 

sheesh, both my VE A/Ts idled at 500 rpm when warmed up.

 

God I love this place. An answer all the way from South Africa that should save the noob in Texas a buttload of time. Thanks.

I actually just changed a pretty dirty air filter and PCV valve

Now off to find something on IACV cleaning.

 

Decided to stop sitting around and just do it. Removed the 3 screws that held the stepper motor in and it slid right out - less than 1 min. There was a whole lot of carbon baked on the valve. Went to work on it with a toothbrush and throttle cleaner and replaced it. Seems to work just fine now. Beats taking off the coolant hoses.