I suspect I may have a malfunctioning (failing?) idle air control valve. Every once in a while (I wish it were more consistent) I start the truck and it immediately dies... unless I hold the accelerator to maintain 1000 to 1500 rpm. Typically, as the engine warms up, the engine operates normally. Only once, the problem occurred with the engine at normal operating temperature. To remove the idle air control valve appears to be a very simple task (Only two screws from an easily accessible location.) I’m sure there’s a proper technique for checking it’s function to determine if it‘s okay, needs cleaned or needs replaced. I’d like to know how to test and if appropriate, clean to restore proper function. If it needs replaced , fine. I just don’t like throwing parts at a problem “just in case”. Especially $140 parts. Any advice would be appreciated.
Jwalker
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post your truck yr engine .. test your gas pressure post on here.
also post any codes .
the IAC is not gonna control cold starts .. when the engine gets to normal temps the IAC will control a small amount of the eng rpm.....so you stated engine warm idle is good ....
also post any codes .
the IAC is not gonna control cold starts .. when the engine gets to normal temps the IAC will control a small amount of the eng rpm.....so you stated engine warm idle is good ....
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don't throw parts on your truck.. you have no codes well you must check the fuel pressure ..key on eng off pressure must be 60-62psi .. pressure should hold up a few min..pressure port pass side..
if the pressure is good and then it drops could be the fuel regulator on the upper intake manifold on driver side.pull vac hose off the reg... if it smells of gas or has liquid gas many had these failures..
if your pump has low fuel pressure then replace the fuel pump and the fuel pump relay...change the fuel filter.
if the pressure is good and then it drops could be the fuel regulator on the upper intake manifold on driver side.pull vac hose off the reg... if it smells of gas or has liquid gas many had these failures..
if your pump has low fuel pressure then replace the fuel pump and the fuel pump relay...change the fuel filter.
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on the GM OBD1 1994 vehicles the ECM does not do a good job on diagnostic testing. OBD II 1996 and newer the PCM will throw codes quickly and then diagnostic data to check on the items having a defect.
the newer trucks do indicate fuel pressures but on a 2000 GM truck no fuel pressure data ..he has to do the fuel testing ..do not throw parts on it ...
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