Question about 1991 Ford Festiva

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TPS failure all at once my 91 ford festiva decided it didn't want to idle, and i went from 49 mpg to 28. it runs good when you are driving (aside from the excessive fuel consumption) but is really rough at an idle. so much so that it dies. I believe that the problem lies somewhere in the Throttle position sensor wiring. the input voltage to the TPS is -6.8 volts and my book says it should be +5 volts i think that there is a short some where but im not sure how to find it or even if that is the problem. also i can't get any codes off the ECM. any help would be greatly appriciated. thank you.

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It may not be a short. it may be a ground problem. it's a good chance that if it were a short it would definitely throw a code,however there are several sensors in the fuel system. you have an O2 sensor which would explain the bad fuel milage or the iac valve or your fuel pressure regulater could be the fault. what's puzzling is the fact that your ecm is not throwing codes. generally i don't like to say it's the ecm itself on such a newer vehicle but it's happened before. these are just some options to think about. please rate this thank you.

Posted on Aug 29, 2008

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