'94 Ranger 4.0L Poor Idle

[bigbo400]

My '94 Ranger 4.0L 5 speed Manuel ran fine until about a week ago when turning a corner it stumbled (bed miss) then CEL came on but ran fine. I drove a couple of miles and parked, Turned the motor off and waited about Min. When I re-started it ran really rough and was smoking black smoke badly but CEL was off, Rived the motor to clear the extra fuel from the cylinders and the CEL came on and it ran fine for a short distance. CEL went off and again it ran really bad. I managed to get to a coffee shop and parked for about an hour. When I stared it the CEL was off and it ran fine for about 15 miles interstate driving to my home.

I called a Friend of mine who works on my vehicles and he told me it was either the coolant temperature sensor or the MAFS needed cleaning. I replaced the coolant temperature sensor and cleaned the MAFS, Neither of which helped.

Thanks to the info found here I did a self test KOEO and got three codes..

111

57...

Intermittent in Park/Neutral/Switch or Neutral Pressure Switch Circuit-PNP or Transmissions..

58...

Idle Tracking Switch (ITS)signal problem ISC

Vane Air Temperature (VAT) sensor out of range or open


Any help would be greatly appreciated..
Bo

 

[pimtool]

I would check battery connections, grounds and some of the wiring harnesses. Maybe something shifted and has a poor connection. Thats alot of stuff to go wrong all at once. Maybe you could get in there while its running and start wiggling wires and such to see if anything changes.

 

[bigbo400]

Thanks for the suggestion but that was the first thing I tried.

I had never heard of a "Vane Air Temperature" sensor until now. Did some searching and found that it's better known as a "Air Charge Temperature" sensor and is located on the intake manifold..

Got one ordered and should be here tomorrow, So, we'll see what happens.

Bo

 

[bigbo400]

I made a dumb mistake of not properly reading the instructions on pulling trouble codes with self test. After reading again I found that I was not counting the pulses properly..

The trouble codes were actually 157 and 158, Not 57 and 58.

replaced the MAF sensor and all is good now.. Problem resolved.

Bo

 

[Tbars4]

...Thanks for clearing that up, posting an update, and congrats on getting it fixed...:biggthump

 

[David89]

Did you ever get water in your engine?