Rebuilt the Motorcraft 2150 on the 351W in my 66 F100 because the accelerator pump was leaking gas onto the manifold. Otherwise truck ran fine. Now the idle wants to swing. Sort of a performance cam sound to my stock engine. Neighbor said vacuum leak, but it runs good except for the idle swinging.
Any ideas?
One thing that has me wondering now is the power valve in the rebuild kit looked different from the one I removed. The original gasket had a delta shape on the inside, but I used a circular gasket from the kit on the new power valve. The delta stlye in the kit partially covered up the holes.
Clark
There where several power valves that Ford used in the 2100 series, rough idle, rich mixture or swinging idle is one of the signs of a wrong one . When you removed the power valve cover was it full of gasoline if so the power valve is bad. If it was not full of gas you might put the old one back into the carb and see if it clears up your idle problem. The other issue would be the check ball and rod. Did you place them back where the came out of. the wrong position will result in the same idle problem.
I posted a autolite/motorcraft 2100 rebuild guide in Hints and Tips (AUTOLITE2100) a little over a year ago- might cover something I have forgotten about-
Hope this helped Brian
1966 F-100 LONG BED, 240cid 3 speed red and white, Red and White Interior with a Mossy Oak Seat Cover
2013 Ford F150 STX Supercab 5.0 litre
DETERMINATION: The feeling you get right before you try to do something incredibly stupid!
CONFIDENCE: Is the feeling you have before you fully understand the situation!
It could be a vacuum leak from a gasket in the rebuild.
Take a can of wd40 and spray the carb while it is running and see if it causes the engine to speed up which means that there is a leak at that point of the spray. More than likely the last post will fix your carb problem. Spray the vacuum hose also because they could have cracked when removing them.
