1997 K1500 Wont Start

[aleebee156]

Yea I can't hear the pump at all. Unfortunately my neighbors are gone for the weekend. Trying to find a second set of ears/eyes. From what I can tell tho, i can't hear anything.

I do have a test light and a multimeter. parts store didn't have the fuel pressure gauge for rent. Gonna have to ride my bike to the farther store if I need it. might go do that.

 

[east302]

Here are a couple of links for testing the relay and power to the pump. I've never had to do it before, but it looks like you can jumper two terminals to see if the pump runs.

See post #6 where he talks jumpering the connector from battery positive to the test connector. The connector is on the side of the relay box facing the windshield.

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http://www.truckforum.org/threads/fuel-pump-relay-testing.10034/

You can also accomplish the same thing by jumpering the terminals at the relay box. See link above and video below:

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Here's another one where they test the relay circuits:

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And here are the GM diagnostics for testing the fuel pump if you aren't hearing it run...

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[aleebee156]

Thanks, running through this stuff now. I have confirmed that there is no fuel pressure.

 

[east302]

So you're getting zero pressure, right?

The video with the guy with the toupee looked to be a good test for checking power and ground at the relay.




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[aleebee156]

yea i get zero pressure from the gauge. Then i also checked pressure while jumping the leads 30 and 87 and still got no fuel pressure (jumping 30 and 87 should give pump constant power with ignition in acc on position). At this point I think its a bad fuel pump, but suppose I should make sure wiring at the pump is good so I know no wiring between the relay and the pump itself is bad. So wrapping my head around doing that, I'm only so so with electrical so takes me a minute to make sure Im doing things correctly

 

[east302]

With the multimeter, connect lead to battery positive and other lead to a jumper wire in terminal 30. If you get a battery voltage reading, then that means the circuit through the pump to ground #G404 is good.


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[east302]

Step 12 in the GM procedure would also be the test for power and ground before the pump. So if you didn't get voltage at terminal 30 on the relay box, you could see if you get it at the pump with the pump harness disconnected.

If you do (with a jumper from battery positive to the fuel pump test connector) then, to me that means an issue in the pump or a bad ground at G404.

I couldn't find a better diagram, but 404 is on the inside left framerail near a crossmember. Might as well check that it's clean and on good.


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[AllThrottleNoBottle]

yea i get zero pressure from the gauge. Then i also checked pressure while jumping the leads 30 and 87 and still got no fuel pressure (jumping 30 and 87 should give pump constant power with ignition in acc on position). At this point I think its a bad fuel pump, but suppose I should make sure wiring at the pump is good so I know no wiring between the relay and the pump itself is bad. So wrapping my head around doing that, I'm only so so with electrical so takes me a minute to make sure Im doing things correctly

Just for kicks, you might want to bang on the fuel tank a few times with a piece of wood, etc. (not to the point of denting it or anything, of course) and see if the pump will start up. Usually works best if someone's banging and another person is turning the key on, though. It's a real down-and-dirty, shot in the dark, rat's ass test, but I've had a few and heard of a few come back to life (temporarily) this way...would at least confirm pump in tank issue. Just a thought.

 

[east302]

Sorry, forgot to attach the diagram for ground 404...

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A whack on the bottom of the tank is worth a shot.


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[aleebee156]

Just for kicks, you might want to bang on the fuel tank a few times with a piece of wood, etc. (not to the point of denting it or anything, of course) and see if the pump will start up. Usually works best if someone's banging and another person is turning the key on, though. It's a real down-and-dirty, shot in the dark, rat's ass test, but I've had a few and heard of a few come back to life (temporarily) this way...would at least confirm pump in tank issue. Just a thought.

Hitting it didn't do anything, but yea worth a try. I even recruited some kid walking by to turn ver ignition while i hit it ha. Worth a shot.

With the multimeter, connect lead to battery positive and other lead to a jumper wire in terminal 30. If you get a battery voltage reading, then that means the circuit through the pump to ground #G404 is good.

East302 - G404 looks good. I get voltage when taking this reading. If i read both your last two posts correctly, if I get voltage as you mentioned above, you are thinking in the pump is the problem.

Looking down there at the tank and wiring its evident that someone else has been in there before. I got truck with 150,000mi on it, currently at 211,000. Trying to decide if I wanna pull the bed off or drop the tank down... thoughts? bed off seems easier to actually work on the fuel pump and change it, also seems fairly simple to pull the bed off. i will have to drop a few extra things like my tow hitch which is covering 2 of the bolts holding the bed on. otherwise i think its simple. Dropping the tank actually seems like more of a hassle and more difficult to work on. Thoughts? getting dark here, gonna wait till tomorrow to do anymore plus i need to wait for the parts.

Part online about $160, at local store all are about $230