What I was afraid of happened. I pulled and cleaned the throttle body today plus I cleaned the idler air control valve. Put it all back on and my idle which is normally 800 rpm is now 1700 rpm. I suspect it is my IAC valve. I did not have an idle problem before this. I have a 1993 Dakota, 5.2L engine.

Thoughts?

 

If you disconnect the battery and then turn the key all the way on like you are trying to start it for 30 seconds then leave the battery disconnected for at least 5 minutes it should force the PCM to relearn things and cause the IAC to readjust. There is a reset IAC option on the SnapOn MT2500 scan tool. Maybe some of the blue tooth scanners that use your smart phone can do this?

 

Sounds like you damaged the plunger when you cleaned it by pushing in on it. Might have to go to the dealer and buy a new one. Don't buy parts store junk for your dakota.

 

That sounds nuts but I believe you. Trying it now. What does turning the key do without battery power?

 

I tried not pushing in on the plunger and don't think I did but who knows? Agree about the part. I'm wary of a parts store brand. Dealer wont be open till Tuesday probably.

 

Would a busted up gasket between the filter housing and throttle body wig it out?

 

I doubt it. I'm 99% sure my truck doesn't even have one.

 

I didn't think it mattered either but thought I'd ask. I have another gasket on order anyway.

 

It drains residual energy in the system. I am not sure it will work to reset the IAC. On my new one it instructed me to spin the center piece in or out until it was extended to the same length as the old one. You may have spun it while brushing it clean. My theory on cutting the power is that while the PCM relearns the systems it might reset the IAC

 

Well, I did the battery-key-battery thing and it did not make a difference. I just pulled the IAC again and re-cleaned it. Put it back in, no difference. Looks like I'm headed to Mopar on Tuesday to get a new IAC.