I have a 2000 Chevy Blazer.Thought the fuel pump had went out replaced it,now the fuel pump will not work.Can pour gas in the throttle body and blazer will start but want stay running.What could be my problem.All fusees and relays seem to be good.Can not nor have not heard the fuel pump,seems like its not getting power to the new for manufacture fuel pump.unsure of brand name of fp but had to change one of the fp plug ins before installing.It has one flat plug with 4 wires and one square plug with 4 wires unsure what each do?No cuts or breaks in the fp wiring.

 

I have moved your post to a thread of your own since it really doesn't sound like the problem as described in the other thread other than the whole not starting thing. The other thread turned out to be an ignition system problem which you have basically ruled out by stating that it will run with fuel dumped into the intake.

Has anything mentioned here or in the tech articles helped you? What have you checked (fuses/relays/etc)? Are you getting power to the pump (do you hear the pump prime)?

 

I got a couple for you..

replaced fp with new or used from a junkyard/pull a part?

if new what brand?

Have you checked any of your lines for kinks, cuts, etc?

if you replaced the fp yourself, did you make sure everything was hooked back up properly? did you make sure it was grounded?

sometimes the most difficult problem is caused by a loose wire.

 

There is information we arent getting that could be clues.

Why did you think the fuel went out in the first place? Because you couldnt hear it prime? Did you ever hear this one prime?
What did the actual electrical connector to the pump {not the pressure sense} look like? Square with 2x2 contacts or flat.. four in a row?

See this attach. Ohmmeter from pin 87 of the relay {see relay} to chassis grd should be less than 5 ohm

 

Yes all fuses and relays are good.No we can not hear the pump this is also way we thought the fuel pump went out.

 

So did I.. but it was good. The problem was in the FP connector in the harness.
- Why they went to different style

Why I asked if it was the old or new style connector.

 

I change the fuel pump on my 92, after changing it the pressure would at 1st go to about 60 pounds, but it would quickly drop off to about 20 pounds.

I tested it 3 more times & it did the same.

Them the next time I tried to start it, & it started OK, & idled very good, I was suspired it started.

Them killed it, tested the pressure again, & again it quickly dropped off. I actually feared I was going to have to do it over. But I checked the wires. My ground wire was not grounding good although it was good & tight. I found this out using a volt meter. Unhooked my ground wire, made sure all surfaces were clean, hooked it to a different spot, & all was well, for it would them hold the pressure for a long time.

The ground wires is what many people will check out only after they have tired everything else, & it ought to be checked 1st. Bad ground will cause many problems.

 

When I replaced my feul pump there was 4 wires on the truck and 4 wires on the on the new harrness purple was one and easy but then it ot enter resting, because I read some were before I did the job that there was 2 power wires and one was constant and one wasnt, So anyway that took care of the 2 power wires because the purple was so easy to make out, but now on to the ground wires. I read some were also that one of the black Wires had a white stripe on it, and it did on the new harness but not on the truck, but the I noticed that one of the ground wires on the truck and on the new pump was a little bit bigger gauge I mean not that much but enuff to tell. Oh and the best way to do it is put the truck on jack stands, so you can use the jack for the tank and a board about 2 foot long.

 

The blazer had the 2x2 style,The new fp came with the new flat plug which was color coded same color as the wiring on the blazer