Strange Idle Activity - HELP!

[vengeful]

I've been trying to avoid this issue for a while now (since before I went to the beach), because I thought it was just a freak occurance. Well, after getting my truck out of the body shop and no change, I figured I'd try to reset the idle using the idle screw.

 

Well, that worked, for about 2 hours.

 

Here's what's going on. When I initially start the truck, it revs up to about 1400RPM, and then dips down to about 200RPM, and it will stabilize somewhere between 450-500RPM, and hold that consistently as the idle point until I shut it off. And it will repeat this start when the truck has sat for a few hours.

 

Also, when I let off the gas going down a hill or coming to a stop, it seems that the truck goes out of gear (at least one would think so by the engine speed, but it doesn't.)

 

Also, when I'm at a stop, the Air-conditioning gets down right hot, but when I'm moving it's ice cold. I was told that the fan clutch may be worn out. I would tend to believe this because when I'm sitting still with the engine running, the AC gets hot (no air moving across the condensor to cool the refrigerant), and the water temp gage starts to climb (again, no air flow across the radiator to cool the coolant).

 

There is also a gnarly belt squeal which as just shown it's ugly face today. Could this be causing the symptoms of the hot A/C/coolant?

 

I tried to set the idle back to 750RPM using the idle adjustment screw, and it did hold 750 for a while, but it's back at 450-500 RPM. There also seems to be a loss of power. :furious:

 

This is on my 99 Pathy with just over 95k miles.

[kmgar99]

Definitely check the fan, and if you replace it, you might consider an electric instead of the HP robbing clutch style. Also check the idler/tensioners for a bad bearing...a bad bearing could cause excessive drag on all the items connected with that belt....You can check the bearing by removing the belt and trying to spin the item by hand. Also check them by trying to move the item up, down, side to side for excessive wear.

[Runnerman]

The squeel might be your alt as per the water crossing I know the wifes pathy is still making sounds and it's worse when it's wet.

[Runnerman]

I should add here if you alt is going on the blink and it's on it's last legs that could screw with your idle.

[02silverpathy]

Hmm, didn't think about a bad alt but...all the normal stuff like a clean TB, clean MAF, checking all vacuum hoses (i know there is a $hit load!),...this one is tougher check the EGR valve that butterfly may still work correctly but have too much tension moving up and down causing idle to be less liquid and more of a straight line.

 

I pulled mine off before Summer and cleaned the little port using a small (tiny) flat head. There was not much crud, but and crud removed is better flow for the EGR, i got a couple of chunks out of my pathy, i have gotten GOBS out of other cars with our mileage!! (i just hit 90k myself) If you give a squeeze on the EGR and she doesn't move very easy start looking for that replacement, luckily mine is still somewhat smooth!!! If you are unsure about how much resistence it should have to go Autozone and get them to show you one..from any car...unfort. i can't describe how tight it should feel its just a feeling.

 

As far as that AC, I noticed that she does lose coolness sitting still too...there is an awesome discussion in the "garage" about a Ford Taurus electric fan......I know you probably already saw it but it was worth mentioning. I spent over an 1.5 hrs studying this idea.

[vengeful]

MIL codes are as follows:

 

P0505

P0325

P0505-PD

P0325-PD

 

505 is idle control system malfunction.

 

325 is knock sensor 1 circuit malfunction.

 

[XPLORx4]

You didn't figure it out yet from the replies on AC?

Edited August 1, 2005 by XPLORx4

[vengeful]

Well, Dean...yes and no.

 

I've tried to locate the IACV-AAC Valve, but I can't tell which one it is. If you could show me an actual picture of it (not like the diagrams that lewinsc posted, I couldn't find anything in there.)

 

If you could show me specifically where to look, that would be GRRRRReat.

[XPLORx4]

Sorry, I don't have any pics, but based on the diagrams it looks to me like the IACV is located at the rear of the intake manifold, close to the firewall. It may be possible to reach around the EGR-BPT valve (a "flying saucer"-shaped valve mounted to the rear driver's-side corner of the intake.) to find it. It may be as hard to reach as that blasted 6th spark plug.