Inconsistent or rough idle

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Oct 10, 2010 | 02:53 PM

forresterdobbs

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Joined: Sep 2010

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Inconsistent or rough idle

My truck is a 1993 F-250. 5.8L with 5 spd. Recently my truck was idling really rough and eventually it started shutting off completely. I changed the Fuel Pressure Regulator and it started running way better. Then shortly after the check engine light started coming on periodically. Now if I drive the truck down the high way or have my foot at the gas pedal at all the check engine light doesn't come on. If I stop and let the truck idle, the check engine light comes on. If I am driving down the highway and take my foot of the gas and let the vehicle just roll along, the check engine light comes on. Also, when I come to a stop the engine keeps running hard, as if I were reving the engine. If I lightly press the gas pedal the reving stops and the engine slows down as if to a natural idle. If I take my foot off the gas pedal the engine either goes back to reving, or else it begins to idle very very slowly and sometimes shuts off.

Any tips.

Thanks,
George Dobbs

Oct 10, 2010 | 03:50 PM

polarismuddman

Senior User

Joined: Aug 2010

Posts: 399

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From: Central, Florida

Sounds like your TPS may need to be replaced....You need to pull codes and post up your findings. Go here Ford Fuel Injection How To Run a Self-Test

To test your TPS check out this writeup: http://www.f150online.com/forums/lig...ttle-body.html