Hello I just picked up a 96 S10 blazer 4.3 4wd. Auto. When I bought it it was very difficult to get it to start, I could use ether and once it started would stay running. Previous owner told me it was the fuel pressure regulator. Eventually it would not start at all anymore. I don't have access to a fuel pressure test gauge, but depressing the schrader valve the pressure seemed way to low, so I replaced the fuel pump with a Spectra brand pump, fired right up and drove great for about 4 days. It started having a real bad miss, not backfiring or anything like that just like a dead cylinder or 2, but only while driving, in park idled perfect, could rev throughout the RPM range without issue. My first thought was that it was bad gas (occasionally use the old gas from junked vehicles).
My friend agrees and says I should just drive it or drain it, I decide to drive it and once I get below half a tank it is dead on the autobahn. In order to get it home I use ether and once it starts throw it in gear and floor it, and this works not good, it would accelerate and then fall on its face and then accelerate and fall again, if I let up off the pedal it would die and I would coast to the shoulder and do the process again (got me home). I filled it up with new fresh gas no change in behavior, turn the key to on and press valve little fluid shoots out, not like a 60+psi fuel pump should be supplying.

I guess my question is how common is it for a new fuel pump to go bad, I did a little research before buying the pump and knew not to get an Airtex, is Spectra in the same boat as Airtex? Is it possible that the FPR was always bad and now it's so bad that it wont even let the pump prime? Also forgot to mention but I did change the fuel filter and put some HEET (water absorber) in the tank. I have no trouble codes and did some data logging and everything looked perfectly normal.

Thanks for any suggestions.

Ken.

Also at this point it wont start at all even with ether it will sputter, but not run. Possibly the Crank position sensor?? What do yall think?

 

Until you get a fuel pressure gauge and follow the steps in 96+ Fuel System Diagnosis you won't be able to tell anything about the source of the problem.

 

+1, until you do, you can get a flashlight and look down the throttle body. If it looks clean or has any gold patches you know you have a leak in the plenum. Could be the FPR or injectors.

 

Thanks for the replies and the link. I went to the only person I know that would have a test gauge...and he didn't.

I turned the key on and pushed the valve, and nothing came out. I pulled the tank cover off and banged the tank with a hammer, turned the key on and this time had fuel, even started and ran for a second or 2 before dying. Thinking pump, hate to order another one though, should I wait until I can actually test the pressure or does this sound pretty clear cut that the pump is bad?

Also popped the intake hat off and didn't see any clean spots in the plenum.

 

On prima facie it sounds like a pump issue, but without going through the steps in the link I provided, you cannot be sure. If you replace the pump, do it with an AC/Delco or Delphi brand, not some aftermarket. They are almost guaranteed trouble.

 

Dropped the tank today, pulled the pump out, hooked it directly to a 12v source barely spit and sputtered. Rockauto is going to exchange it for another one, had I kept the original packaging I could've gotten a refund and just bought the ACDelco one. I'll give Spectra another chance by default and hang on to the packaging this time. Thanks for yalls help.

 

Never buy a Spectra fuel pump. The 2nd one worked for about 3 minutes, I put it in started it up and while I was cleaning up and started bringing the lift down the Blazer died and didn't run again. I dropped the tank again and checked all my wiring, everything was right. I kept the original package and sent it back for a refund and purchased an ACDelco pump, the pump showed up used and broken, so that one went back while another one was on the way. New one showed up, triple checked the wiring again and installed the tank again...it didn't start. I fashioned a fuel pump pressure gauge out of some old R12 hoses and gauges (wish I would have thought of that about 6 weeks ago) and once I bled the air out of the line it fired right up. I have about 55 PSI with key on and about 51 PSI while cranking. It's been a week now and no problems to report fires right up and doesn't have that dead cylinder feeling anymore. I'm just glad that it finally worked, I'm sure the people at RockAuto think I'm nuts buying so many fuel pumps, but the IROC is away for the winter and I'm putting around in my Blazer.

The End.

 

Key ON, engine OFF, fuel pump running: pressure must be 60psi to 66psi and must remain above 55psi for at least 10 minutes after the pump shuts off.