Weird Idle.....

[WyoXplorer]

Drove my wife to work yesterday morning, waiting at a red light and my idleing starts acting erratic, jumps in 500Rpm inciments (between 900-450 Rpms stalls around 400ish).

at the gas station the same afternoon, reversing out of the parking spot, died.
started up with no problems.

turned my vent fan off to open the windows, it stops.....but starts up again randomly.

It seems to happen when I'm using an accessory.....but not always.

any thoughts?
It's driving me crazy.

 

[corkey]

could be a bad alternator,, that would account for the accessories thing,, but does the voltage drop on the guage too,, ??

 

[Dan Whitaker]

Sounds like a dirty MAF sensor or IAC to me.

My alternator died on me yesterday on the way to work and it didn't do what Wyo explained.

When I had it checked it was putting out zero at idle.

 

[corkey]

yes, they would cause that weird idle issue as well, a good cleaning of both sounds like a good idea , would account for the idle dropping,, as the accessories are used, the engine has to idle up a bit, and if they are sending bad signals, it won;'t speed up the idle, ,
Dan could be right,,
but be on the safe sid, check all 3 , idle air control, and mass airflow , and alternator,,

 

[alohamonte]

This doesn't sounds like what happened when my ALT died either.

Check the usual suspects such as vacuum leak and tuneup parts.

 

[WyoXplorer]

well after I installed my cold air system........and started the truck after putting the positive back on....letting the ECU re-coup I noticed my A/C Compressor clutch was engaged....and after dis-engaging immediatly re-engaged.

I know one thatng and while being 53deg outside, that shouldnt happen after I had the heater on the last time I drove it.....i have noticed it before and did nothing not knowing what I could do.......so I located the controller plug and unplugged it......clutch dis-engage no attempt to re-engage.....and my truck stabalized it's idle.......

Bad A/C Compressor?
Bad Sensor?
or is it just a bad clutch?
Either way I am alsmot certain it has screwed my A/C Compressor to where I need a new one.....I HAVE ONE!!!!!

 

[polarbear199]

If you are still having these problems, try cleaning the throttle body with a $3.00 bottle of throttle body cleaner. I was having similar issues and it cleared up instantly.

 

[pkeats]

I found that the A/C cycles on when in either of the windshield defrost modes, and the
inside temp guage is not in the full hot position. A ford mechanic said it was something
to do with drying the air properly for defrosting.

 

[robertoa1a]

As per the A/C cycling mine was doing that when I was running my heat as well. That's with a brand new compressor. The A/C works fine. I don't need heat now but I don't want to wear out my compressor when winter comes again. Is there a thermistor in the dash or something?

I'm going to agree with the others on the idle problem. Maybe unplug the IAC for a minute to see a change.

 

[WyoXplorer]

As per the A/C cycling mine was doing that when I was running my heat as well. That's with a brand new compressor. The A/C works fine. I don't need heat now but I don't want to wear out my compressor when winter comes again. Is there a thermistor in the dash or something?

I'm going to agree with the others on the idle problem. Maybe unplug the IAC for a minute to see a change.

Where is the IAC on these?
I havent really dealt too much with these trucks to know off hand.

thanks again guys.

 

[robertoa1a]

Mounted on the throttle body, A sort of sideways cylindrical gadget. Its an idle air control. I don't know If it is bad but or not but you can check.

 

[WyoXplorer]

Well I'll deffinetly be checking into that.

although for such a small piece with a simple purpose the prices are kinda scary.

AutoZone: $103.99
Advanced: $86.99
Napa: $144.00

I usually shop at AutoZone cause I've had better chances with thier parts.

Napa has always been more expensive for whatever vehicleI have ever owned.
while being cheaper for my friends, until Rob bought the VW lol.

 

[robertoa1a]

Then I would start with the cheep stuff first. ie Cleaning the MAF and IAT with MAF safe cleaner (not carb cleaner), Checking plugs etc... Thees things are almost free to do. Worst case; you may have bad upper intake gaskets. I kind of doubt it though because because you didn't mention the issue as being temperature sensitive.

My thread was next to yours and I started it about the same time, titled: Idle problem or something. You might want to read it and see if any of this is familiar.

I still think you got a good deal. O'riley has good deals on parts too.