Air Temp Sensor question
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Air Temp Sensor question
Has anybody had to replace there air temp sensor? Im trying to track down my hard start when warm problem. I pulled the air temp sensor and it was covered in black sludge. Ive searched these forums and nobody seems to speak of this sensor, which must have some significant purpose. Anybody notice there truck ran different when it was replaced?
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From: Central NY
I don't think the IAT is that crucial to the system, its used more for 'fine-tuning'. Mostly EEC uses the barometric reading it gets from the MAP or calculates from the MAF, form what I understand that is.
Tim
*the aforementioned is solely conjucture unless proven otherwise. The poster is not a real technician and only pretends to be one while cruising the internet.
Tim
*the aforementioned is solely conjucture unless proven otherwise. The poster is not a real technician and only pretends to be one while cruising the internet.
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The IAT is a pretty robust component. Hard starting when hot is usually a fuel system problem. In Fuel Injected Systems, if the system can not maintain pressure, a vapor lock condition can occur when hot. You may need a new fuel filter. Check your fuel pressure. When you turn the key to ON, but not START, listen for the fuel pump, it should turn on briefly to pressurize the system. Have you done a tune up recently? Old spark plugs, wires, cap and rotor could also be the source of your problems. Have you changed your PCV valve? Sometimes the PCV valve will stick open, or partially open causing problems.
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I have replaced the plugs, wires, cap, rotor, fuel filter, fuel pressure regulator,engine coolant temp sensor, and flushed the injectors twice. fuel pressure is at 34 psi i believe.
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If you have done all that, and the problem only happens during a hot start, perhaps the ECM is malfunctioning when in closed loop mode. Before spending money on an ECM, check your throttle body for carbon buildup, and make sure your idle air bypass valve is not sticking. Other tests, would include trying to start the engine after it has just warmed up, as well as after long drive. If it fails start under both of those conditions, I would suspect the ECM. Also, will the engine start if you gently open the throttle when cranking? If so, perhaps the throttle position sensor may be to blame.
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I would check for leaking injectors before spending the big green on the lil computer.
They can cause this problem too but start fine cold because the gas has had time to leak past the rings. Fuel pressure shouldn't drop more than 5psi over 30 seconds (koeo)
They can cause this problem too but start fine cold because the gas has had time to leak past the rings. Fuel pressure shouldn't drop more than 5psi over 30 seconds (koeo)
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I have cleaned the iac valve as well as used a can of combustion chamber cleaner to clean out the intake. The truck has to sit for at least 10 min before its starts bad. If you shut it off and restart it with in a few minutes it starts fine. It does seem to help if you press the pedal to start it. according to the scanner i had on it the tps is functioning properly going from around .5v up to 4.3 or somewhere around there. Im not sure as to how a guy goes about checking injectors. i did put a pressure gauge on it a while ago and it dropped from 35 to about 10 psi in around 15 mins. ii have replaced the pressure regulator since but have not reattached the gauge. I dont want to replace anymore injectors than i have to. what would be a good way to check which ones are at fault??