its a work truck for our small business, 1995 3.9ltr 2wd auto reg cab long bed that has 193k. it runs great when your on the gas, doesn't smoke, starts great and gets decent millage, around 15. I think thats decent for that motor and truck combo. we just got it a couple weeks ago for a parts runner truck.

the two issues we have are the idle, its a not horribly rough but has a slight miss, you can feel it at a stop light just enough so that you know somethings up. i just replaced the cap, rotor, plugs, and wires it got a little better but not really. so what is my next step.

the CEL only comes on when i have been driving on the freeway around 55-60 mph for like 15 min without really getting on it, but the kicker is as soon as you shut the truck off the CEL goes away and won't come back on till you repeat the scenario. So how do i find out what code it is tossing if the dam light won't stay on? the truck doesn't seem to run any differently when the CEL comes on either.

thanks for the help

 

Did you get the code read? It may be the coil or an injector.

 

well i got curious and read the codes to see what if any came up. 12 32 and 55 which i believe to be: 12 normal check, 32 egr failure, 55 no signal from the cam sensor.

so would the rough idle be caused by the cam sensor, or the erg failure. i think the cam sensor is the culprit. Where is it located on the 3.9ltr?

i bet the check engine light that comes on while driving down the highway is due to the EGR failure. so what does that one mean, do i need to just replace the EGR valve?

thanks again!

 

nobody? well i replaced the cam sensor and still am getting the no cam signal at pcm code(54) so wtf? what else do i have to do to make this run right? So the codes i just got after replacing the cam sensor plate are 12 54 32 55 in that order.

12) batt disconnected in last 50 key cycles

54) no cam signal at pcm

32) Short or open in the EGR solenoid circuit. Check for loose, broken, or shorted wire in the EGR valve wiring and connectors. Possible air fuel ratio imbalance not detected during diagnosis.


55) End of message code. A DTC 55 is used to end all DTC messages. This code does not show on the DRB tool and indicates a completion of the stored codes on the Malfunction Indicator Lamp (check engine lamp).