I am thinking I have a bad fuel pump on my 95 Blazer. The car will not start. I can hear the fuel pump when I turn the key to the on position but it keeps on running, it doesn't turn off after 2 seconds like most do. Also when I turn the key to the off position after this I can hear the fuel pump running for a few seconds. I am thinking this means I need a new pump, but the last time a pump quit on me there was no sound at all coming from it. Suggestions?

 

The only way to know is pull a pressure test. There are several threads on how to.

 

check the fuel pressure with a gauge at the test port on the back of the intake where the fuel lines enter the intake.you need 60 psi for it to start..here's some more helpful info..https://blazerforum.com/forum/showth...ht=fuel+system

 

Here is some information for what it is worth. The factory manual for a 95 Blazer says 58 psi.

I have a 96 that was intermittantly hard to start but ran fine. The pressure was 53-55 psi.

One day it refused to start and the pressure was 33 psi.
I installed a new pump and it starts and runs great. However the pressure now is 47 psi. which should not allow it to start.

 

Look at the fuel pump relay in the fuse box under the hood. swap it with the horn one to test it out since they are the same.

 

those are the newer blazers i believe the 95 is behind the glove box.. theres three relays all identical. I forget which is the fuel pump but when you have it open. turn the key to on with the engine off and you'll feel the "click" in the fuel pump relay. swap it witth either of the other two in there to test the relay..

its normal for the pump to run a few seconds after you turn the car off.. but it should only "prime" for 2-5 seconds when you put the key in the on position.. if its running longer either your relay is bad, theres a short between the vcm signal wire and ground- causing the relay to stay energized..

you may also want to check and see if theres gas in your intake... it shouldn't make the pump run longer but it would explain the no start...

ultimately.. do the fuel pressure test.. its the only real way to tell let us know what you get for a reading..

 

The fuel pump relay on a 96 is the one on the driver's side in the glove box.

 

I tried swapping the relays and get the same thing. I also removed both relays completely and the pump still turns on and keeps running. Is this normal? I would think the pump should not turn on with the relay removed. I am going to Harbor Freight today and pick up a fuel pressure tester so I can check that as well. Thanks for the input so far.

 

There is an oil pressure switch that turns the fuel pump on when the oil pressure comes up. Possibly this switch is stuck activating the pump. This would explain wht the pump runs with the relay out.

 

I hooked up a tester today and got 58 psi at first then after about a minute or two it went down to 55 psi where it stayed. I can hear the fuel pump priming but it never seems to stop priming. Suggestions?

Edit: After I did the pressure test the blazer started right up. I am officially stumped now. However with the car running I can hear that pump humming if I get outside and listen near the tank, it just seems louder than normal. I am still thinking bad pump or a pump that is slowly dieing.