Skip the auto shop - Our mechanics make house calls

Q: Why does my Tahoe start with the fuel pump relay pulled out or left in?

asked by on

I been having starting problems at times.. My 1998 Chevrolet Tahoe with the 5.7 Vortec will crank right up then die.. Then you try to crank it again and it fires up and it's fine it seems the rest of the day.. I'm just puzzled I can't understand why it starts with the Fuel Pump Relay pulled out and with it in? I was told to pull the relay and see if it stopped it from starting. I was told it should not start with Fuel Pump Relay out ,, but funny thing it does start an run.. My question is..Is my Fuel Pump Relay bad??

My car has 220000 miles.
My car has an automatic transmission.

A: Hi there. Check to see what relay you have ...

Hi there. Check to see what relay you have pulled. If indeed you removed the fuel pump relay and the engine still starts up, then check the oil pressure switch. An oil pressure switch will kept the engine running as it passes battery voltage to the fuel pump. When the engine builds up oil pressure, the oil pressure switch sends voltage to the fuel pump and bypasses the fuel pump relay. Unplug the oil pressure switch and see if the engine stops running. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from Your Mechanic, who can assist you with why your vehicle is still running with the fuel system relay removed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Car cannot pick up fuel

The first step is to check fuel pressure at the fuel rail. For your vehicle, pressure should be 30 to 40 PSI while running and 35 to 45 PSI with the engine off. Since you've already replaced the pump, if...

Q: Gas consumption on my car.

Hi there. The readings that you are getting with the MAP sensor is correct. Since your vehicle is burning fuel like crazy, check the fuel filter for if its dirty. Check the injectors for if they are sticking and draining...

Q: Primed with injector fluid and car shut down

Hello there, thank you for asking about your car. Well, it's not getting fuel, that's for sure. This could be because of a botched fuel pump replacement or some other reason. The first thing you want to do is check...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...