Thread: Wont start without giving it gas

2008 Grand Prix
Base Model
3.8L Series III

This does not happen all of the time, but, occasionally, when I try to start it, turn the key and it will try to start but won't. If give it just a little throttle it will start up every time.

A few things that I am guessing would be:

Fuel pump
Fuel Filter
Idle air bypass

Is the pump filter a single unit?

Wondering if anyone else has had this experience and could help me rule somethings out before throwing money at it.

Thanks,
John

FYI 130k miles, fuel pump filter IAB all original

Or if it's hot starts only I would investigate the Fuel pressure Regulator.

Does your coolant temp gauge work properly?

Pinpointing a common denominator in these cases is very helpful

Originally Posted by Scottydoggs

pretty sure the fpr is in the gas tank on a 08, not on the rail like the older cars. and those dont seem to fail. at least ive never heard of one failing.

that's highly likely. I can't seem to remember a FPR on a l26 rail.

In any case, it sounds like a fuel mixture issue. Either too much/too little fuel, or it's having a hard time metering air. Data logs would help, or ability to monitor live data, otherwise it's just guesses.

I can only remember it happening on cold start, will check with daughter.

You mention data logging, the only thing that I have is a Bluetooth OBD2 reader, it has some data logging, what should I log, or is this not available?

Thanks for all input.