Van only starts when gas pedal pressed?

2003 Chevrolet Express 3500 6.0L V8

Van won't start when cold only when gas pedal is pressed

Changed fuel filter, IAC valve, cleaned throttle body, still doing the same thing, getting a code for MAF sensor low circuit however i don't want to throw $150 to see it not working...

The van is perfectly fine and runs great and when it is warmed up it will start right away, no issues when driving and only need to press the gas to get it started, it idles fine...

Please leave your suggestions, i am thinking the TPS sensor next

2 Answers

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  • 7 years ago
    Favorite Answer

    It could be the ect(engine coolant temp)sensor.This sensor tells the computer what the coolant temp is so that it can adjust the air fuel ratio properly for all driving conditions.When the engine is cold,the computer richens the air fuel ratio to keep the engine running.When the engine warms up,it leans out the air fuel ratio.If the ect is defective,its telling the computer that coolant temp is higher than what it really is,so the computer is probably leaning the air fuel ratio instead of richening it.That's another reason why the engine will start when you give it a little bit of gas because you're adding fuel by pushing the gas pedal.The computer will normally add enough fuel to start and run the vehicle but since the ect is sending a false signal,you pushing the gas pedal down is taking care of adding the fuel needed.One thing you should do though is clean the maf sensor.The signal from the maf to the computer also plays a big role in adjusting air fuel ratio.

    Source(s): Electrical contact cleaner works best.Be very careful though.Use the cleaner sprayed onto a qtip and clean the little heated wires on the sensor located inside the housing
  • 7 years ago

    Did they clean or replace the Throttle bypass valve. This unit allows air to bypass the main opening of the throttle body and opens and closed with engine heat. A cold engine is designed to start up rich meaning extra gas is sent in. If no air is passing naturally it will flood out and not start without you pressing the pedal. The device will cause your complaint.

    Source(s): mechanic since 1975
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