Expert: Robert Summers - 12/10/2008

Question
For about a year now my truck won't stay runnin. It runs for about thirty seconds and quits,no matter how many times you try unless you keep pumping the gas.Once it warms up it does pretty good.If you try to drive it before then it speeds up and down,you cant keep it steady.I've changed about all the sensors,spark plugs(tune up),timing and cleaned the injectors still no change.

Answer
Hi Anthony... if you can put a scan tool on it and watch the MAP sensor... is it steady or does voltage go all over the place...if it is up and down check the vacum to it as well as all the other vacum lines..check for a vacum leak around the throttle body and intake...also check vac hoses to make sure they arn't sucking themselves closed....it sounds like you have a vacum leak somewhere.. i would be more inclined to think that because it gets better as it gets warm it would be around the intake...a quick test would be to install a vacum gauge and watch it...vacum should be steady, if needle jumping all over the place you have a leak... hope this helps...Merry Christmas