I've just started having problems with my 1997 Ford Explorer Sport. When I turn on the A/C or the defroster the engine revs up (tach goes to 2000rpm), then the engine spudders for a moment, then the truck shuts off and the check engine light and battery lights come on. The past 3 days I've tested this and consistently get the same results (revs up, spudders, turns off). Believe it or not, I've never replaced the battery, not bad for a factory original. So I'm very tempted to replace the battery anyways, and then see where I'm at.

Anyone seen this before? Any ideas?

Thanks,

- pezcrew

 

My guess is the Idle Air Control (IAC) valve. It controls the idle and will compensate for the added load of the A/C. There seems to be an above average number of failures, not for your symptoms though. It is possible that yours has failed though where it can't regulate the idle with the added load. When most fail, the engine just refuses to idle at all.

 

The check engine and battery lights will always come on if the engine stalls and the ignition is still on.

So the only problem you have (I think) is in the idle system, as mentioned above.

Winford

 

Thanks guys, I looked up IAC in my Haynes Explorer manual, and couldn't find any info on how to adjust this. So I've made an appointment with the dealership. I'll let you know the outcome.

peace,

- pezcrew

 

Guys,

I stand corrected. There "is" info about the IAC in the Haynes book afterall. It involves removing the connector and checking the voltage and resistance (ohms). Standby, I'll let you know the results.

- pezcrew

 

ok, I checked out the IAC and mine appears to be slightly different than the one in the book, mine actually as a black rotating **** on the outside. I marked its original position and rotated it left 90 degrees and tested it - engine still dies when I turn on the A/C or heat. I rotated it right 90 degrees, still same problem. Is this really an adjustment ****?

I unplugged the 2 pin connector and checked the voltage on it with the truck turned on, but the engine not running and it checked out at 12.09V. I couldn't check the resistance though across the two IAC pins because they're so far receded that I can't get at them. In fact, I accidently started up the truck and with the connector disconnected the engine dies immediately with no heat or A/C (douh!). I connected it backup and I'm back to where I was - Truck runs perfectly fine until I turn on the A/C or heat.

My stepfather recommended checking the vaccum tubes, but my assumption was that the truck would run like crap all the time, regardless of whether or not I had the A/C or heat on. But I checked them nonetheless, and didn't see anything visibly wrong.

So, does anyone know anything about this black **** on the IAC?

Thanks,

- pezcrew

 

The black **** is not an adjustment **** (it's not a **** at all). If you pull it hard enough, you will see a small felt filter inside. All it is is to keep the dirt out of the IAC. Rotating it does nothing. I haven't looked up the procedure to test the IAC but you probably have to cut in to the wires going to the IAC to fully test it while it is connected. It sounds like all you tested was that your IAC has 12V at the harness. You need to find out if the IAC valve operates within its proper range. I haven't had to do that so I'm not certain how it is done. Shouldn't be hard though.

 

Well I took it to the Ford dealership. The verdict: air compressor is seized up. Cost: $650 parts, $350 labor.

I'll let you guys know how it is when I get it back.

peace,

- pezcrew