SURGING OR ROUGH IDLE INTERMITTENT

[Jerry]

Howdy, I have a 95 Explorer 4w Eddie Bauer...lately the idle surges, seems to surge more with the heater activated. Does not do it all the time. Another thing that may be related is the idle gets so rough when pulling up to a stop that the streering wheel shakes, again not all the time.
Otherwise truck is running fantastic, getting about 15 here near Chicago in the winter.

Any help would be greatly appreciated, Jerry.

 

[DOGMAN]

Jerry,

First thing I would check would be the fuel system. Start with the fuel filter. This can cause rough performance if clogged. If that's not it, it's possible you have a problem with one or more injectors. You can have them cleaned, which involves running the motor on cleaner/solvent for a period of time. Your mechanic or dealer could perform this for you. Another possible cause would be the fuel pump, but this is not as likely, although possible.

If it's not the fuel system, it could be one of the many engine sensors malfunctioning. This is a distinct possibility.

As far as it gets worse when the heater is on, do you mean when just the heater is selected or when you run the fan? The fan would be loading the engine more, especially at idle.

If it was me, I'd take it to a good mechanic or the dealer. Most of the fixes I mentioned need not be attempted by the inexperienced. The fuel filter, at least on my 91, needs a special tool to be able to remove the old filter. Plus, it can be dangerous to remove the old fuel filter, since gasoline will likely spill, then there's the fire hazard. Unless you're an experienced driveway mechanic, I'd leave it up to the pros.

Good luck!

DOGMAN

 

[Jerry]

Thanks for the response. I've dropped it off at the dealer this morning. It should be covered under warranty. I think it might be related to something that should activate a fast idle. I can hear a vacuum noise under the intake plenum just as the engine rev's.

Jerry

 

[Jim F]

Sound to me like the idle up for the AC is not working. When the heater is on, the AC compressor kicks in and out depending on the temperature outside. This is normal on Ford's and Chevy's.
I bought a used car with a third party type AC system in it. They did not hookup the idle up wire, so I did it myself. Whenever I turned on the AC, the car idle would drop from the load and the car would shake badly. After I hooked up the wire, it worked like normal and is still working. It's an 87.
Hope this helps if Ford can't find the problem.

------------------
Exploring CA
98 XLT 4X4 4.0L SOHC

 

[Jerry]

Turned out to be the aircondioner compressor was locked up. Good thing I bought a warranty with this vehicle when I purchased it at 90K. The warranty company/dealer has coughed up near $3K so far.

Jerry.

 

[DOGMAN]

Good call, Jim F.

DOGMAN