Hi, all. Here's my issue.
I have a 2000 Dak (3.9, 4x4 auto), which is giving me grief lately. I posted recently about an A/C problem I was having, which has not since cropped up again. Basically, the "coolness" would stop cooling, I would turn the AC off for a few minutes, and all would be fine again. NOW, I don't know what goes on.
As we all know, most Daks, barring mods, will idle around 600-750 RPM. So does mine. Usually.
NOW, it's like it just dropped out of overdrive all the time. It'll idle around 1000, and it absolutely screams going down the road, as if I had a stick, but was waiting too long to shift. The shift interval seems to be the same, but it acts as if I was overdriving it, so to speak. The only changes lately: the aforementioned AC issue, and I recently replaced my rear speed sensor. I also, for some reason, am getting a P0442, small evap leak. This, as we all again know, is usually the gas cap. I tightened her up, reset the computer (which, BTW, I also did after the sensor replacement), and went. It went fine for a couple days, and then came back. This cap is pretty new, bought in the last few years, when my OEM cap bit the dust.
I just reset the PC again, but haven't yet driven anyplace.
So, question: could any of these things be affecting, or causing, my current problem? I appreciate any help, cuz I'm a bit leery of driving anyplace I don't have to.[sm=smiley35.gif]
Thanks!

 

Helloo? Help!!

 

1. just get a new gas cap. the problem will go away. maybe you just droppedit and didnt realize it.
2. did you do anything to your engine like put a different viscosity oil in or something?

 

Nope. Don't do my own oil changes *hangs head in shame*
So the gas capcan be responsible for the crazy RPMs?

UPDATE: performed another PCM reset (pop neg cable, turn key 15 secs)-no code (yet), but still running high revs.

 

no the gas cap could be responsible for the vapor leak. i had the same problem. i was reading a q&a site and they said that the high idle might be because the MAF(mass airflow sensor) is dirty and it causes the sensor to be slightly off. so maybe you should try to replace it. it might work.

here is the site: http://www.2carpros.com/topics/idle4.htm

 

Thanks, I'll look at that. Might these symptoms be caused by a bad TPS? Sems like it might be, based on what I've seen in my research.

 

ya possibly you might also want to check it out

 

idle issues are usually related to the IAC either being dirty or being on it's way out. it could be sticky as well. pull off the thottle body and IAC off the TB and clean it real good. usually the idle problem is a stalling problem. yours may have dirt built up to the point where the valve cannot close all the way causing the high idle.

while the TB is off, look down onto the plenum for any oil pooling on the bottom (sign of a leaky plenum gasket). you'll need a mirror& flashlight...