Engine surging
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New User
Joined: Jul 2003
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Engine surging
I've got a 1987 F250 Supercab with a 351W 4bbl auto (lot's of pollution garbage on it@#!*). I just had the heads overhauled and finished installing them. The truck runs great except I think I've got a carb problem. I was not having any problem prior to this repair.
The truck runs great cold. Once it gets to operating temperature and is running at steady part throttle cruise conditions it starts to surge. It goes from running strong to complete idle as if you had let your foot off the pedal and then sputtering, picking back up and doing it all over again. As soon as you put your foot into it it takes off strong again (sometimes there is a slight hesitation).
I have set up the float level, checked and rechecked the vacuum lines (although there are so many I am still not completly sure I have them all), checked the needle valves and all seems in order. Any suggestions
The truck runs great cold. Once it gets to operating temperature and is running at steady part throttle cruise conditions it starts to surge. It goes from running strong to complete idle as if you had let your foot off the pedal and then sputtering, picking back up and doing it all over again. As soon as you put your foot into it it takes off strong again (sometimes there is a slight hesitation).
I have set up the float level, checked and rechecked the vacuum lines (although there are so many I am still not completly sure I have them all), checked the needle valves and all seems in order. Any suggestions
Thread Starter
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New User
Joined: Jul 2003
Posts: 4
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Engine surging
Thanks for the info. Was looking throught another post and found a link to the Chilton on line info. Found an EGR routing that was different than that shown in my Haynes manual, rerouted the lines and fixed the problem. Thanks again for the info.
Senior User
Joined: Jun 2003
Posts: 114
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From: Harlan, KY
Engine surging
If you have a vacuum operated advance on the distribuitor, check it. I traced a surging problem on a 1963 Olds Cutlass to a leaky diaphragm. Could'nt hold a steady speed, but was good with foot into the throttle. Put a light vacuum on it , pinch the hose and watch the advance mechanism for a few minutes. It will slowly move if there is a small leak.
