I have a 2000 Mercury Marquis and often in the morning it barely runs for
two or three minutes. Requires several restarts. Once it runs a bit all
clears up and car runs fine.
Car has about 66000 miles.
It does not turn on any error lights - it just runs rough.
Just a little bit ago I tried starting the car but it seemed to not want to
go at all. After about a dozen attempts and many restarts it finally decided
Any help appreciated
I guess I could go spend a couple hundred at the Ford house and get it
analyzed better, but my budget is sort of limited.
Regards, Ted S.
Probably the idle air control valve. I'll paste a post from 02 with a
picture from my 4.6. I drew an egg shaped circle on it and added a line
from nowhere in particular to the bottom bolt.
THE IDLE CONTROL VALVE
Submitted by pro-five-oh / 10-23-02
Having a funny idle problem? Already did a normal tune up with fresh
spark plugs, PCV, fuel filter, cap/rotor and maybe even new spark plug
wires? Did you run a code scanner and got nothing? It is time to clean
the idle control valve.
Depending on whom you talk to, this little gadget is called the ISC,
BYP, IAB or IAC valve. Whatever you call it, the valve goes bad due to a
broken motor or soot buildup from crankcase vapors. The answer is to
clean the assembly or, if all else fails, replace the motor attached to
the unit with a fresh one.
Where is it?
On EEC-IV multi-port EFI motors, the idle control valve is located on
the throttlebody. The valve has a cylindrical shape with a small wiring
harness at one end, with another casting that attaches to the throttlebody.
There are two 5/16th bolts holding the valve to the throttlebody.
Disconnect the harness with a small flathead screwdriver and unbolt the
valve. Check the gasket that attaches the valve to the throttlebody for
any damage or cracks, and replace if necessary.
With the valve in your hand, generously spray light oil such as WD-40,
or a throttlebody/carb cleaner in the two bores of the valve. Shake the
valve around to ensure the cleaner is moving freely in the bore. If
possible, get a length of fuzzy pipe cleaner and use it to scrub the
bores to a shine.
Shake the valve until most of the fluid is expelled. Repeat the above
procedure if the expelled fluid is extremely dirty. Reattach the gasket,
the valve and its wiring harness. You should see a dramatic difference
in the idle control of the car.
Thanks - your information was spot-on. Also, the photo was worth a thousand
The part is $50 at the parts place, but I ran into the old situation of "our
computer says we have it but I can't find it".
It will be available leter this afternoon.
Thanks again, Ted S.
Another chapter on the air valve - if you can lend an ear for a moment.
I took the valve to my local shade mechanic and after a while he said the
valve was the wrong part.
I go back to the parts house, but get the same answer - "there is inly one
I finally rounded up some tools and took the valve off myself and - yes -
they seem to be different. My original had a connection to a half inch air
pipe which the new one did not have.
I just ignored the pipe and installed the new part and engine idled nearly
like it should. It's too slow and tends to die, but it doesn't run rough
Question is - - DOES THE VALVE CONTROL IDLE SPEED? I may have to spring for
the real Ford part ( $100 ) after all.
I am really tired of all the troubles replacing a simple valve. Every step
requird at least one 45 mile trip.
Maybe I'll go shopping for a 66 model pickup.
You're way ahead of the game if you avoid the dealer costs for
exchanging this simple part. I can't answer your question but since you
have the old one off why not try the cleaning that was described in my
first response. I've done mine three times (so far). If you look
inside you can see a little shaft and spring. They get a little coated
and that makes the shaft stick. WD-40 works well but anything you have
would be OK. I always leave a film of lubricant on it before reinstalling.
In the replacement valve I do see the shaft with the spring, but in the old
original there's not much to see and nothing that appears cleanable. Maybe
I'll spray some carb cleaner in there.
That's the idea. Then shake it, if you have air blow it out. Doesn't
take much and the process of removal and replace is quick. If it works
(should) maybe you can return the other one. If you have WD40 good. If
not try something else (not heavy) before reinstalling.
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