Good day,
I have a 1997 Jeep Grand Cherokee (with the 318ci in it) that has recently started experiencing something like extreme vapor lock. Here are the symptoms I have observed:
- Only occurs after ~5 miles of sustained high-speed (>50 mpg) highway driving. (At lower speeds, never really have the issue)
- Air intake into the throttle body starts spitting and sputtering (choking sound)
- Extreme power loss
- RPM becomes eratic and drops to 300-600 rpm
- Turning off the vehicle for 30-45 minutes will allow it to go again.
- Information from diagnostic computer:
- DTC: P0171 - "System too lean (bank 1)"
- DTC: P1765 - "Transmission 12v supply relay control circuit fault"
- Load: varies between 4.5 and 6.6%
- Coolant Temp: steady at 175 degrees.
- Intake air temp: steady at 135 degrees.
- MAP Sensor: 3 in.hg
- One notable item that stuck out in my head was that usually the MAP sensor sits at 8 in.hg, but when this is happening, it drops to 3. Not sure though if this has something to do with it.
Any suggestions to send me in the right directions would be appreciated.
Thanks,
A