No start cranks and spark no fuel

[Xxl2]

I have a 1991 c 1500 4.3. I was driving it and it just stopped got it restarted once and that was it. So far i have check my 20 amp fuel pu mp fuse under the hood. I poured gas down the throttle body it runs. Its just my injectors are not spraying fuel. I ll check to see if i have piwer at the fuel pump tommarow . Its never been to easy to hear. Any thoughts. Thanks

 

[Schurkey]

1. What is the fuel pressure?

2. How old is the fuel filter?

3. Are the fuse(s) that power the injectors in usable condition?

 

[Xxl2]

The filter is less than a year old. I ll check if i have any fuel pressure tommarow. And look at the fuses. This truck has 400k miles

 

[Xxl2]

Went put this morning it did start for a second but died. My though is week fuel pump and it built some pressure over night that helped it

 

[Schurkey]

How would it build pressure overnight if there's no power to it?

 

[CumminsFever]

I once owned a 93 s10 with a 4.3 that did exactly as you describe. Died on the freeway, no fuel to the motor. On a whim, I grabbed a hammer and thumped the underside of the gas tank where the fuel pump is located. Voila, starting action! Drove the 10 miles home and replaced fuel pump.
I'd recommend a quick check of fuel pressure. If you bump the motor over, the pump "should" run for a few seconds. Yes, the 4.3 fuel pumps seem extremely quiet compared to all the other tbi trucks I've worked on.

 

[Xxl2]

now that my tank is dow when i turn my ket should i see 12v at the fuel pump concetor? also i have three wires on my connector which ones should i test?

 

[Schurkey]

now that my tank is dow when i turn my ket should i see 12v at the fuel pump concetor?

The tank is down?

You won't have power to the fuel pump except for 2 seconds for the prime cycle when the key is turned to "Run". Otherwise the computer has to have an RPM signal to turn on the fuel pump relay, or the engine has to have oil pressure for the pump to run.

The pump has to be RUNNING to test voltage to it. If the pump doesn't run, the voltage test is almost meaningless.

also i have three wires on my connector which ones should i test?

Seems to me there's a fuel pump power, a fuel level sending unit power, and fuel level sending unit ground wire. The fuel pump ground wire is separate.

Download the service manual set from the links on this web site, and that'll confirm the wires and their color codes.

 

[Xxl2]

To test the fuel pump wiring can i jump pin a to pin c ?to make sure my wires are good going back to the fuel pump

 

[Schurkey]

"A" to "C" on WHAT? There's at least two blocks in that diagram with positions labeled "A" and "C".

If you're talking about the relay, I'd say that'd be best. The fuel module would be questionable.

Or just go to the ALDL connector and put power to "G". That wouldn't test the power supply to the relay, (fusible link, and wire leading to "A".)