Hi there! I bought this van back in November and so far it's been great for the age, only 78k original miles. There has been an issue with it idling a bit high at times so that it's hard to get into reverse without making a big clunk though other times it's just fine. It's actually gotten better since I've had it, there were times after starting when it would idle high at first and try to correct to a lower idle that was like too low maybe and then kick up again and back and forth like that for a few minutes. It hasn't done that much recently but still seems a little uneven and too high some times. I don't suppose the PCM is bad, maybe a sensor that feeds it info? I took it to a garage and they couldn't get any codes that were relevant and they couldn't reproduce the issue because it happened to be working perfectly on the day I had an appointment for. Has anyone else had issues like this that were able to be resolved with this model or similar ones?

 

Welcome to the site..

Might check the IAC solenoid, more so for intermittent, or for any unmetered vacuum bleeds.
The throttle body as well,for any hanging..

 

Something that can get overlooked,
The engine is supposed to idle a little higher until the engine coolant comes up to temp.
A coolant temp sensor may not be totally defective, but deliver incorrect info to the computer. It can work right sometimes and if it says the engine is not up to temp, will cause slightly higher engine idle speeds.

 

You might try and unplug the IAC when the idle is high,, does the engine then reduce RPM’s?
ECT, may increase RPM but may run more rich if so..

 

Thanks for the responses! Unfortunately it's not easy to reach the IAC in the van without removing air filter housing. I would like to just replace the IAC and cross my fingers that's it's going to fix it but there are too many other things that it could be. I've heard that unplugging the IAC may stop the high idle but doesn't necessarily indicate that the IAC is bad. I may just unplug it and drive it like that until I can get a good diagnosis in order to keep the high idle from putting more extra stress on the transmission when shifting into reverse. I ordered a Delphi IAC already in case that's the problem, I can return it if I don't end up installing it.

 

You have two choices to make the job a little easier
One is to remove the Doghouse inside the van which can be a little hassle if the 2 bolts that hold the doghouse to the floor are badly corroded.

The other is to remove the air filter assy. All you need to do there is to remove the two 8mm head screws that hold the bracket to the sheet metal of the firewall.
Unplug the PCV filter hose from the air filter housing and last loosen the 2 hose clamps that hold the hoses to the throttle body. The entire filter housing now can be removed easily and goes back on the same way..
Now you have easier access to the area you might need to work on. Once you see how easy it is, it will make some jobs a lot easier to do.

 

I found the IAC and was able to unplug it but the idle was so low that it wasn't practical to try to drive. It seemed to be surging also. I took it to another shop yesterday but it hasn't been idling so high last couple days as it was earlier this week so they weren't able to try diagnose anything without being able to observe the problem. They didn't charge much for it at least. This makes me think my best option is to just change the IAC and see if it acts up again and then try something else until it doesn't come back. They said some Seafoam in the tank might clean things up that could cause the problem.