QuestionHello Van, when i start my truck after setting several hours it doesn't start for 6-9seconds than revs to about 1500 rpms and stalls,restart the same thing only it slows to about 900rpm runs for a few seconds and stalls. then on the third attempt it act the same except it stay running. once running it is hesitant, pumping the throtle can get up to speed. after driving for several minutes the engine light comes on. on the highway even on a slight upgrade the transmission shifts out of overdrive because it doesn't have the power to mantain that speed,replaced plug, rotor, cap, wires. cleaned fuel system, air cleaner. thinking it's sensor, cc, don't really know, can you help. thanks R.B.
AnswerHi Ray,
I would check the fuel pressure. I would connect my tester, and leave it connected overnight to see what it shows during that cold start.
A vacuum leak also comes to mind.
I assume you have cleaned the idle air control valve?
It shouldn't be a sensor, because most of the sensor signals are ignored till the engine reaches operating temperature.
It could however be the coolant temperature sensor telling the ecm that it IS at operating temperature, when it really isn't.
That sensor will be different than a sender for the temp gauge. It will have two wires, and probably be right next to the thermostat.
Van
