Periodic CEL, codes thrown: TPS and Intake Air Temp Sensor?
Subject truck is my 1990 4G64 2.4L with a manual trans, base model.
Rcenlty gone through a upper end rebuild with new head, gaskets, all new sensors, throttle body rebuild as well as front end replacement on engine include all new seals, bal shaft bearings and timing belt.
Truck runs good but I get an occassional CEL and low idle, and while drive sometimes at constant cruise RPM, but almost always when slowing down and come down through the gears.
I checked for codes and I get both TPS and Intake Air Temperature. The TPS I get as I recently had the throttle body gone through and I havent yet calibrated the TPS to the FSM spec (IIRC, between 0.48->0.51V at idle and at temp). So this might accoutn for the TPS being (occassionally) out of the spec range the ECU is looking for.
I suppose the big question is the Intake Air Temp Sensor. I pulled it and did the FSM procedure to check the harness (ground, and 5V supply good), and the resistance of 2.7ohm at 68deg F seems to be fine too. I breathed hot air on it and the resistance dropped to 1.9V so it seems to be reacting correctly.
Has anyone seen this code before? Does it become an intermittent problem? There have been a few days I ran the truck and it was sub-arctic cold outside. We're talking -35deg F witht he wind chill a few days in Jan. I was wondering if there is an operational limit to the sensor where it just hits an operationl limit (per FSM, and overvoltage condition?) and thus throws the code.
I'm assuming my intermittent CEL is related to the TPS code, just wondering what others have experienced with the Intake Air Sensor.
Tags for this Thread