"John J" wrote: 94 Taurus 3.0 L
Surges at idle when cold. Removed IAC valve,
cleaned it, sprayed in some carb cleaner, and
repeated twice. Drained it out, blew dry, and
replaced. No dice. PCV valve is good, and I
can't find any obvious vacuum leaks. Any help?
My car had the same symptoms, typical of a defective
IAC valve. I did all of those same cleaning steps with
no success. After checking out every other sensor
or gadget I could think of, I went ahead and bought
a new IAC valve. That fixed it.
You look hard enough, you will find plenty of deteriorating vacuum
hoses. If there cracked, replace them. Look around the passenger side
plenum first. Then there is a vacuum hose that turns into a plastic pipe
then turns back into hose for the canister purge (as i recall). this
goes across the engine and goes down the drivers side front down to the
lower radiator area. Some of the hose may be in split loom. Look at it
carefully. Change your fuel filter. Clean your maf sensor and change
your air filter if you have not done it yet.
Look at your engine running at night in the dark. If you see ANY arcing
or electrical activity around the plug wires, change them too. If the
wires are original, you should change them anyway.
If yours is the same as the 95 version, there's a plastic tee in the
vacuum line right of the manifold port. Had a high idle, surging, found
it cracked.. just moving it affected the symptom. Any brass tee.
Yep... that, too. But as others say, cleaning the IAC does not always
work... especially if the problem is in the motor side.
Yeh, I'm a Krusty old Geezer, putting up with my 'smartass' is the price
you pay..DEAL with it!
Thanks guys..yeah, I'm gonna take another look at hoses, already did have to
replace PVC hose was cracked...and at the other end of the throttle body,
found another break in that small line in the split loom, replaced it....so
some more looking is in order, before I plunk down any cash. Never thought
to check plug wires. Thanks for the tips...appreciate the help. JJ
Follow up..sure enough, did find another vac hose shot..replaced it. Wires
looked good, no arcing, etc. Sooo.. went ahead and tried a new IAC valve.
There ya go. Idling great.. nice and smooth. Got lucky I guess, although
NAPA's price was steep.
Thanks again for the help everyone. JJ
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