99 Sierra Intermittent Stall

John Peters · May 23, 2011

Have a 99 GMC Sierra. Engine has been sporadiacally stalling for past three years.

Last summer I replaced Fuel Pump with Delphi part (good pump) around $350.00, replaced the fuel filter and the Gas Pressure Sensor.

Since then engine has stalled three times that last being this past Friday night. I called tow truck and the dude squirted ether into intake, and truck started right up. So I drove it to a gas station, and filled up tank getting ready for a 100 mile trip. After filling tank, engine died, wouldn't restart. Dumped in a lot of ether over a 30 mintue period and just couldn't get it to start. Knocked real hard on fuel tank to see if pump needed a tap, no luck. Camped out in motel that night and called tow truck next morning.

Tow truck arrived and the dude took a 2 pound hammer to tank and it started right up. He suggested I follow him to the station and they'd put a ODB reader on it. Good that I did, car died again in parking lot of garage. ODB read nothing. So mechanic put on a pulse checker to injectors and saw no electrical pulse. He then suggested I replace the Pulse senser down there by the starter which apparently runs by magnets and sends pulses to injectors. He pulled it down off rack after putting it in, truck started right up, I started driving home. 20 miles later in middle of highway, stalled again. I pulled over to the side of road and waited 15 minutes, it started again.

Looking for suggestions at this point. Note one other thing I checked were the ignition related relays. I swapped with other ones that had same number. Don't think it has anything to do with relays.

Any suggestions would be much appreciated.

John Peters · May 24, 2011

Have a 99 GMC Sierra. Engine has been sporadiacally stalling for past three years.

Last summer I replaced Fuel Pump with Delphi part (good pump) around $350.00, replaced the fuel filter and the Gas Pressure Sensor.

Since then engine has stalled three times that last being this past Friday night. I called tow truck and the dude squirted ether into intake, and truck started right up. So I drove it to a gas station, and filled up tank getting ready for a 100 mile trip. After filling tank, engine died, wouldn't restart. Dumped in a lot of ether over a 30 mintue period and just couldn't get it to start. Knocked real hard on fuel tank to see if pump needed a tap, no luck. Camped out in motel that night and called tow truck next morning.

Tow truck arrived and the dude took a 2 pound hammer to tank and it started right up. He suggested I follow him to the station and they'd put a ODB reader on it. Good that I did, car died again in parking lot of garage. ODB read nothing. So mechanic put on a pulse checker to injectors and saw no electrical pulse. He then suggested I replace the Pulse senser down there by the starter which apparently runs by magnets and sends pulses to injectors. He pulled it down off rack after putting it in, truck started right up, I started driving home. 20 miles later in middle of highway, stalled again. I pulled over to the side of road and waited 15 minutes, it started again.

Looking for suggestions at this point. Note one other thing I checked were the ignition related relays. I swapped with other ones that had same number. Don't think it has anything to do with relays.

Any suggestions would be much appreciated.

Any takers?

owenbyc · May 24, 2011

in my opinion just my opinion sounds like the pump cause usually if you hit the tank then it fires up you usually have a pump kicking out. the only thing i could think to do is you have a fuel pump prime terminal under the electrical cover under hood. connect a 12 volt test light and turn the key over. if the light lights up then you know your prime is working. if that works i would hook up a fuel pressure guage too. if im not mistaken you should have between 55-62 psi. my truck test light lit up so i knew that primer was working right. i had the guage hooked up and no pressure was indicated. so i changed my pump a nd problem solved. when i did mine i had to crimp on a new wire connections. if you did you might have a lose connection. when i bought my pump a friend at a local chevy dealership told me to stay away from the delphi and delco ones. he recomended a airtex brand. i got it from autozone with taxes under 300. i hope this helps. if your pump is fine then you must have some sort of electrical or ignition problem. just sounds to me that them hitting your tank is making your pump work. mine died on the road. my dad came over with a 2lb hammer knocked the hell outta my tank shes fires right up i got it home and put a new pump in