SLE has trouble starting

[Benvw99]

Could this be a common problem? Yesterday i took my car to school, started and drove fine. After basketball practice, i started it and drove a few blocks to pick up food, perfectly fine. When i came out from the restaurant, it just cranked. Tried it for at least 5 minutes, with using the gas pedal slightly for the last 2 or so. Then i started walking for a bit, got a friend to pick me up and take me back to the car. I tried it 2 more times before it barely started up. Once it was running it was fine.

I had an EGR code about 2-3 weeks ago but i put a new valve on it and it hasnt came back since. No other codes. Once it finally started i drove it home and everything was at full temperature. I tried to start it once i got home and it stuttered but it did start running. Tried it twice more and it only stuttered a little before firing up.

I left it sit for about 2 hours and it was cold again. I tried to start it and it stuttered and fired. I shut it off and tried it again, it stuttered but fired. I left it run for about 5 minutes then shut it off and tried again. Fired up better. I tried it again this morning and it stuttered but fired again.


Any idea what could be causing this? It used to start very well and consistent just before yesterday. A leaky injector? Some throttle sensor maybe? Thanks!!

[MKMike]

Could be one of many things from fuel to ignition.

Assuming the problem is fuel related....
A tank of bad gas.
Sticking open PCV valve. Fuel filter clogged.
Faulty fuel pressure regulator. Failing fuel pump.
Failing MAF sensor. Leaking injector.
MAF sensors are supposed to set a code but they seem to fail without setting a code often enough.

If you ever think it is flooded , put the accelerator all the way to the floor and then crank it over.
This is the "Clear Flood Mode" and will temporarily shut off the injectors.

Vacuum hoses that fail can do this too, since vacuum leaks lean out the fuel mixture and one vacuum hose goes to the fuel pressure regulator and another to the MAP sensor.

Ignition issues can be:
Worn out spark plugs. Faulty spark plug wires.
Failing coil. Failing ignition control module. Bad crankshaft position sensor.

And the list goes on....

I'd start with cheap things first, such as the fuel filter and air filter.
Pull a couple of plugs and see what kind of condition they're in.
If the spark plug wires are original , get a new set of good wires, such as Delphi or ACDelco OE (original equipment) line.

Rockauto is good, especially if you use the discount code (look in Pontiac Bonneville Club Vendor's forum). Amazon , too, especially if you have Prime.

[96 SSEi]

hi, for an easy diagnosis of MAF sensor, you can unplug it and see if your issue changes

[redfury]

A hot restart with a slight stutter and a prolonged restart with a more significant starter spells leaking injectors to me. Reason, the longer it sits, the more fuel is leaking into the cylinders making it harder to fire cleanly. Change your fuel filter for sure, as it could be something that is in the fuel that is gumming up the injectors. A fuel injector cleaning done at the fuel rail with a special pressurized pot would be the easiest way to "clean" the injectors. You may want to consider driving the car, letting it cool down, then cranking it a bit ( if it doesn't restart on you ) and pull every plug and give them the smell/visual test for raw fuel in the cylinders. That would help narrow down individual cylinder(s) that may be causing the problem.