Engine wont idle when cold and runs rough.

DJEMBE

MEMBER
1990 FORD COURIER
280,000 MILES

1990 Ford Courier 2 liter carburetor.
Cold starting engine wont idle, keep foot on accelerator to keep running, runs rough as if missing.
When engine is warm will idle but roughly and at increased rev's. Noticed that the revs fluctuate high to low and back again.
Have replaced electric wiring to air idle control on Carburetor.
replaced all spark plugs, and all leads.
Checked all vacuum hoses for cracks.
Have replaced the carburetor.
Checked fuel line for blockages, replaced fuel filter.
It has been suggested that the carburetor is water cooled, and there may be a problem with a blockage, but I can't see where water cools the carby.

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,645 POSTS

Is this the original engine? If so, have you checked compression? Have you checked for major vacuum leaks?

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Tuesday, November 12th, 2013 AT 9:54 AM

DJEMBE

MEMBER
2 POSTS

I have checked all vacuum lines for leaks.
The problem began over 12 months ago when the wiring to the ICV failed. I replaced that.
The motor was able to idle but very roughly.

A mechanic has my car for a day and could not source the problem.
He did a compression test and all was ok.
Yesterday I replaced the distributor cap, it was very worn, now seems to idle much better.
But when I rev the motor it is very slow in returning to normal revs.

One more thing, I had to replace one of 2 of the ECV located under the intake manifold, I don't know if they both operate the same, but if I they are different and I put the wrong one in, would that cause a problem to the running of the motor?