I just bought a 96 blazer, the guy i bought it from said it needs a fuel pump but im not so sure.It will just crank over and not start but if you spray a shot of starting fluid in it it starts right up and idles fine, if you just feather the throttle it will rev up but if you push the throttle all the way down it spits and sputters and dies.He said he tested the fuel pressure and it was 50 psi, he said it requires 55-60 but i dont know, i can hear the fuel pump running and it sounds ok,they have replaced the fuel filter,fuel pressure regulator,and many other parts,he also said he inspected the spider injectors and they looked ok.He said the fuel pump is just weak a needs replaced, i have always thought either a fuel pumps works or it doesnt, they dont just get weak? i just dont want go through all the work and money to replacing the fuel pump if that isnt the problem so any ideas or help would be appreciated.

 

If it really is 50 then that's your problem. It should be between 60 and 65. I would replace the fuel filter first then do another fuel pressure test. Also, after the initial prime it shouldn't go below 55 for 10 minutes or you have another problem.

 

Yea I agree.. My 02 pump is going bad and does similar to how you described yours. I did the pressure test and I was reading roughly 25psi once the engine was warmed up. I still hear the pump but it's not as loud as it once was. If you do buy one, id recommend summitracing.com to buy from. I ordered a Delphi FG0072 for 287 shipped. Local parts stores wanted 379.99 and up. (mine is the 2 door, which is a higher priced pump) It arrives tomorrow and I can't wait to get it in there. I'm tired of not having a dependable ride. Good luck with your fix.

 

OK thanks for the info, i guess im not really understanding it too well tho, shouldnt 50 psi of pressure be enough or it to start on its own? And if not how is runng on 50 psi after I spray a shot of starting fluid in it?Also mine is a 4 door, not exactly which injector setup is on it but is a vin W.

 

55 is the minimum needed for starting. Its not psi, I forgot what measurment its in. You hook up a fuel pressure gauge to the fuel rail, on the schrader valve. You run the test with the key on, engine off!
Edit: your 96 should have the SCPI injector system,unless the PO upgraded it to the MFI system.

 

It's hard for me to say if yours would start on its on because Iam still learning about this myself. But mine starts but I have to have my foot ready to idle it up as soon as it catches and it takes about 15 seconds of having key turned on before it will crank. And yes fuel pressure is measured in PSI but the Gauges show a KPA measurement as well, which is kilopascal.

 

Thanks for the help, i just got around to changing the fuel pump and it started right up, seems to run good.That must have been the issue.