high rpms

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Feb 27, 2004 | 05:44 PM

trader rob

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From: ky

high rpms

I have a 88 f250 4x4 7.3, is it normal for this truck ,when you wind it out in any gear, not tight mind you , but when you hit about 2000 to 2500 [ im not sure how close the rpms are, tach don't register right all the time]. it is like a 2 stroke coming on the pipe. now im not complaining about the power, but shifting is hard, the rpms fall off slow, so its like speed shifting or when you let them fall it stands you on its nose in next gear. can you see what i'm saying? i drive a truck for a living so i'm not completly in the dark. international of course. lol

Feb 27, 2004 | 06:43 PM

mhalter

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From: Vincennes, IN

I had this problem with my 89 7.3. The likely culprit is the vacum modulator valve. It is located on the side of the injection pump. It is plastic and is adjustable. It has two vacum lines running to it. Replacing this solved the problem for me. I was unable to locate the part at any other place than Ford. It was $90 from them. This is all assuming you have a C-6 three speed automatic by the way.

Feb 28, 2004 | 04:41 PM

trader rob

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From: ky

no i have 5 speed, wouldn't be a problem, but when it gets wound out a little the rpms shoot up real fast then drop too slow. have sprayed off linkage so it is not gummed up. don't know.

Feb 28, 2004 | 05:15 PM

rancherman84

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From: clyde,ny

did you unhook the throtle cable and try just moving the pump lever.if that fixes it ,that would eliminate the cable binding for sure.could be an internal pump problem.