Hi folks,

About a year ago I had a problem with the IAC on my '99 Ford Explorer
SUV 4.0L causing bad idle or stall. Vehicle has now 129,500km. At the
time other things were going on as well, such as pinging under load when
driving on the highway with CC on and starting an uphill climb. It
didn't take that much of a hill either for the vehicle to shift down a gear.

At that time I went onto the internet and this newsgroup to find out
what was wrong with the vehicle, not knowing at that time that it could
be the IAC, didn't even know what that was. Two main suggestions were:
1. to clean and 2. to replace.

I decided to take the unit off the engine, easy to do, takes longer to
find the correct size socket than to remove, and cleaned it with WD-40.
After thoroughly cleaning I replaced the unit and fired up the engine.
This seemd to fix the problem, idle was smooth, ran better so I left it
like that and ran the vehicle all summer.

Just as winter was getting a good hold on us, the unit failed again.
This time I drove into town to replace the unit with a brand new one.
Funny thing, I went to the Ford dealer and asked if they had one in
stock. The person behind the counter asked which 4.0L engine I had, I
said, I don't know, all I know is that it's a 4.0L, is there any other
kind? She said I would have to come back once I found out so she could
order one. Cost was for one, 124.00CDN for one type and 189.00CDN for
the other type.

I decided to drop into another parts dealer who I knew dealed with Ford
parts. Cost here was 109.00. Same question, which 4.0l engine? I said I
didn't know, the parts person asked me for my VIN number. On the VIN
number is the engine code and from that he was able to go back and get
the correct unit.

I got home, took the old unit off and replaced with th new one. Fired up
the engine, purred like a kitten

Now I noticed something else. Before this replacement there was still
the consistant ping under load. That is now gone....totally! Also when
in cruise, it now takes a seriosly steep grade before it shifts down,
instead it powers up and contnues up the hill with ease. Also notice
that when slowing down from highway speed that the vehicle slows fast
now, before it felt like free wheeling.

So to end this long story, I just want to thank all and everyone who
helped me at the time. Sure feels good to drive a vehicle that feels
like brand new again!

Thanks again and a Merry Christmas to all!

Allan