Desperately Need Help! 1998 QX4 idle problem

[AlabamaDan]

I'm out of ideas and need help. Here's the problem: My 1998 QX4 idles at 1500 rpms in drive. When you put it into park it raises the idle to 3500 rpms or revs from 1500 to 2500. Makes it difficult to drive as well as being aggrevated. It's not throwing a code.

Here's what I've done so far: I cleaned the MAF and throttle body. I've unplugged the battery for 24 hours thining it might reset the computer. I read something about teaching the computer what a closed throttle was by inserting the key and turning it on, not cranking it and then back off 20 times or something. In desperation I did that too. Finally I just parked it for a couple weeks and cussed it. Upon cranking it was fixed for about a week and now it's starting up again.

Please help. If I can just find the problem I can probably fix it I just don't know what to do.

[maxnix]

Is your throttle cable adjusted properly (enough slack)?

Check the MAF connedtion very carefully.

Check for vacuum leaks.

[AlabamaDan]

Is your throttle cable adjusted properly (enough slack)?

Well, when I'm out of the car and checking it appears to have enough slack in that it isn't pulling on the throttle. Is that enough?

Check the MAF connedtion very carefully.

Think it still could be the MAF? The connections all look good. I forgot to mention that I cleaned a bunch of connectors around the MAF and TPS with electrical cleaner too. Everything seems to be clean and tight to me.

Check for vacuum leaks.

I don't see any unplugged lines and don't hear an obvious leak.

[AlabamaDan]

Awe come on guys?

[SteveTheTech]

I read this a few times over to make sure I got this straight but I'm still not sure.

When you say your Qby4 is idling at over 3,000 RPMs? At 1500 in gear driving that is like power braking the entire time your stopped with your foot on the brake. Very detrimental to your automatic transmission.

The only thing I can think of that would cause this would be something holding the throttle open. A MAF will cause all kinds of problems and a vacuum leak would cause an increased idle but 3k is extreme. The throttle cable must be sticking on something or the spring is binding and not allowing the throttle plate to close. I have seen something similar to this exact symptom happen on the same year Qx4 had started to fray and stick.

Check the ENTIRE length of the throttle cable.

[AlabamaDan]

We've had snow and extremely crappy (for the South Anyway) cold weather. Didn't get to work on it, but should be sunny this weekend. I'll check the entire length and maybe swap out the MAF with a buddy of mine for testing.