91 F150 Studders

[agco85]

My F150 will suddenly studder when I'm driving, before it gets warmed up. It acts like it either cuts the fuel or loses spark momentarely. It drops approximately 200rpm, but it only does it for approx. 1 second and then recovers. It does it the worst around 35. It also idles a little rough. I already tried a new cap and rotor, and it has new fuel injectors. I had a scan tool on it and all it said was that the idle was a little low. The spark plugs only have 10k miles on them. Any suggestions would be appreciated.

[taillight]

Check distributor pick up and ignition module. These like to do this on high milage fords.

[agco85]

Hey, sorry for the long wait. Do you know what the gear is made of for a standard cam, not the roller cam.

[Davescort97]

It's made of hardened steel. It is so brittle it will shatter if dropped on a concrete floor.

[agco85]

The auto parts store told me that there is two gear types, a cast iron and a steel gear and if you get the wrong one it will tear something up.

[Davescort97]

You might check with the service department of your dealer. The parts counter should be able to tell you. Sounds like a middle of the rear changeover.

[jamfu]

sounds like a fuel pump to me

[mightymouse466]

Mine did this similar thing. Sometimes it would even just die while driving. I replaced my ignition coil and never had the problem again. Check to see if the coil is loose where the mounting ring passes through the coil. If there is play in it. Replace it. Worst that could happen is you improve your mileage.