91 ford explorer engine problems - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

zrb888 · 03-16-2009, 20:32

hello all, i have a 91 ford explorer 4.0 v6. i love this truck as its lifted with 33in tires but the last few days have been hell so ill start from the beginning, about 1 week ago my truck started stalling out driving to work ONLY at night. i could drive to work during the day just fine but would stay out every mile or so at night time. there was no chek engine light at that time but i still read the computer and it came up with bad MAF sensor and bad fuel pump relay so i replaced both of those (126.00 for both) it stopped stalling out but now the check engine light was on and the engine was surging and bad smelling exhuast. so i read the computer on key on engine off and it came up with O2 sensor so i replaced that(55.00) so i replaced that.. nothing... now it came up with crankshaft sensor so i replaced that(75.00) but still was surging... i read online about probably being the Idle Air Control Valve(IAC). i looked in the book and found out how to test it. now here is one of my questions.. should the resistance be always showing on a ohms meter or should it just flash the resistance. it flashed i beleive 7.22(thats how fast it flashed could barely read it) so i decided to clean it and put it back on.... now the engine was really low RPMS(about 450) with barely any surging. could that IAC valve cause all the problems ive listed above and what about the resistance. should a ohms meter always read the resistance or should it just flash?

**360ci** · 03-21-2009, 15:52

Before you go and buy more sensors, when was the last tune up done with new plugs, wires, cap & rotor? If it's been recent (within' 25K) then I'd replace the IAC sensor and hope for the best.