failing map sensor? not detecting the motor is under a load?

 

The plot thickens...

Got it scanned for codes... no codes


TPS was not within parameters, so installed new... no change.

Tried another variant suggested to test TPS.: Unlplug PCM connector 1 and TPS and check for voltage, shows 9.3 volts, which supposedly means its shorted to a power source. not sure if Im convinced its the problem and tearing through the whole damn wiring harness.

 

The map sensor vac line might not be hooked up the throttle body

 

If it almost dies than its your map sensor or you o2. I changed both mine at the same time but Im pretty sure it was my o2 so try that first

 

The map sensor kinda makes it chug rough like it's about to die

 

Well, 5,000 miles later and a traumatic trip through death valley and yet the jeep lives!

Sorry for not getting back to this for a while, returning to reality takes its toll.

The verdict, replaced catalytic convertor and spark plugs. Cant exactly say who was to blame for the initial problem. The plugs were in decent shape with no visible problems and I never got any cat or o2 codes. After replacing cat it ran well for a while then starting having problems missing at high speeds. In desperation I figured why not try new plugs to see if it could boost the spark a bit and help compensate for the lousy combustion. Threw in bosch's 4 point plugs and voila! Its fixed.

In my defense the old plugs had been looked at my myself and two other mechanics who all thought they were just fine. But, hey Im not looking a gift horse in the mouth.