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87 gm tbi hard to start when cold

9K views 4 replies 5 participants last post by  BogiesAnnex1 
#1 ·
hello all, i have a 87 truck it is hard to cold start i have to feather the gas pedal until it warms up a few minutes.. after that it runs really good but when its cold i have to let it warm up at least 5 minutes of stepin on the gas to put it in gear and drivin off without drying or running really crappy no other fuel injected vehicle ive ever driven did this im more of a carberator guy with a choke...
 
#5 ·
chevyAL said:
hello all, i have a 87 truck it is hard to cold start i have to feather the gas pedal until it warms up a few minutes.. after that it runs really good but when its cold i have to let it warm up at least 5 minutes of stepin on the gas to put it in gear and drivin off without drying or running really crappy no other fuel injected vehicle ive ever driven did this im more of a carberator guy with a choke...
Either the IAC is out of adjustment or dysfunctional. This is a linear motor that opens an air bypass for engine idle. Or the temperature sender to the computer has failed. This device is on or close to the thermostat housing. It furnishes engine coolant temp data to the computer, when engine temp is less than 176 degrees the computer is in open loop, cold start mode. In this mode it adds "choke" enrichment fuel for cold start and idle.

A third possibility is a more old fashion event where the exhaust cross over under the intake manifold has carboned up and closed off so no engine heat is available to force fuel evaporation and warm the TBI around the throttles to prevent ice formation.

Bogie
 
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