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1992 4.3 sierra wont start unless gas petal to the floor

6199 Views 7 Replies 5 Participants Last post by  Ethan
what could be my issue? it only starts when i have the gas petal all the way to the floor.
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Almost definitely the coolant temp sensor. When they fail they tell the PCM the ambient temp is about 300 below zero. This causes the PCM to run a very rich mixture, usually to the point the engine won't start/run. When you put the pedal to the floor, it goes into flooded mode, and cuts fuel spray to almost zero. You need the sensor on the intake near the thermostat.
1 - 1 of 8 Posts
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