1998 GMC Yukon FUEL PUMP OR WHAT CAN IT BE?

ANDREAFRACCARO

MEMBER
1998 GMC YUKON
V8
4WD
AUTOMATIC
105,000 MILES

Hi there! I have to pour gas into throttle body to get it started. It hesitates a little but then stays running. I can drive around as long as I dont shut if off and wait till it cools. It will start if I try right away, but not more than 10 minutes. Does the fuel pump only work on start up or does it continually run as long as the car is running? I am stumped and I have no way to get it in anywhere, so I hope you can help. Oh. There is a new fuel filter and new fuel pump relay. Still nothing.

1 Reply

PEAR69

MECHANIC
1,482 POSTS

When you turn your key the fuel pump turns on and your fuel system pressurizes. If you do not crank the engine shortly after turning the key -- the pump will shut off -- but when you crank the engine -- the pump runs constantly -- yes, as long as the car is running.
Being that you pour fuel in the throttle body to get it started may indicate that the Throttle Position Sensor (TPS) may be bad. Test it or have it tested for proper voltage function. Also, try changing the Coolant Temperature Sensor (CTS). Testing the CTS is too complex and they are cheap to replace so just replacing it isn't a bad move.