1991 Explorer EB won't idle...need help! | Ford Explorer - Ford Ranger Forums - Serious Explorations

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1991 Explorer EB won't idle...need help!


New Member
November 8, 2008
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1991 Explorer EB won't idle
I'm helping out a friend who has a 1991 EB explorer that's running like crap.
Here's the codes on the 4.0-liter engine:
112 ACT sensor less than self test
minimum of .02v
117 ECT sensor less than self test minimum of .2v
122 TPS circuit below minimum .6v (tested sensor--good)
157 MAF sensor went below .4v during last 80 warmup cycles
513 Failure in EEC processor internal voltage
556 Fuel pump circuit failure
565 Canister purge circuit failure
566 3-4 shift solenoid failure
629 Converter clutch control circuit failure

I cleaned and verified operation of the IAB valve and solenoid. I also checked the TPS sensor manually for resistance and it was really good. I also manually checked the voltage from the TPS harness and it was indeed low (nowhere near 5v). It seems as if the EEC which feeds voltage to all the sensors is wreaking havoc here...could it be a bad ground to the EEC? Where is the EEC? Where is the ground to it? Any other leads or ideas? If I haven't given you a piece of info you need, let me know...I'm fairly good with this stuff and should be able to relay good info for your recommendations.