A friend asked me to give him a hand with his 2000 Chevy Blazer. It won’t start ! If I put gas in the intake it fires up for a couple of seconds. I checked the fuel pump relay by 1, junping it out, and 2 switching an identical relay. I don’t hear the fuel pump so I would have to say it’s the fuel pump. Because this fuel pump is about $400 I want to be sure. Any thing else I can check? Does it sound like the fuel pump to you?
You could try checking the stored computer for codes P0230 through P0234 and P1221 (if you haven’t reset them) … If no error codes then your problem is most likely the pump.
Thank You, I’ll check out the codes
Check the fuel pressure at the fuel rail. If it has none check for voltage at the fuel pump connection into the tank.
This era of Chevy trucks have a reputation for fuel pump failures. If you don’t hear the pump running and don’t have any fuel pressure, it’s almost certainly dead. Be sure the connection isn’t dirty first, but the fact that it will run with fuel in the intake means you’re not getting fuel.
Replacing a $400 fuel pump because other fuel pumps like it have failed is not very effective troubleshooting.
If it runs when you supply fuel to the intake manifold this indicates that fuel is not being supplied TO THE INTAKE MANIFOLD. This could indicate that the pump isn’t running or the injectors aren’t running. If the pump isn’t running it could be because it isn’t getting the required power to run it.
Check for fuel pressure. If you don’t have it check for fuel pump power at the pump.
Thank you for the informative replies. Can you check power to the pump without removing the tank and pump?
While I’m not intimately familiar with your particular make/model, I think it’s pretty unlikely. You’ll have to drop the tank to gain access to the wires where they enter the tank.
It’ll be pretty tough to access the wiring harness for the pump as there’s not much room up there. You can have a look-see and try, but it’s a tight squeeze.
Jay - Nowhere did I say not to check if the pump is getting power; all I said was that Chevys of this era have a bad rep regarding fuel pumps, so the OP really shouldn’t be surprised if it needs replacing. Take it easy.
400.00 must be parts and labor,these pumpe really were bad,about the only repair I rely on common failure to diagnosis.
The problem could be fuel supply to the engine (fuel pump), or fuel into the engine (fuel injectors). You need some simple, basic, inexpensive test tools to discover which: 1. a fuel pressure tester; 2. 'noid fuel injector tester; 3. multimeter ohm and volt tester.
There is a gray prime wire, near the fuel pump relay, which can be jumpered from a 12 volt source, to power the fuel pump. Did you use that?
You can, also, use that gray prime connector to see if there is a complete circuit to the fuel pump. Use your multimeter, set on ohms, to do this.
Disconnect the electric plug from a fuel injector, and insert a 'noid fuel injector test light. Crank the engine and watch for the 'noid light to flash with each fuel injector inject command.