96 Jimmy 4.3L 4x4. i replaced the spider injector. i must have done something wrong while i was messing around under the hood, because after i got the new injector in and everything back together the truck would start right up but it would stall out and die after a few seconds. i can get it to stay running if i keep giving it gas. double checked all vacuum lines and haven't found any leads there, so i checked the fuel pres. key on pres goes to 55-60 once pump kicks off immediately drops to 20. but while its running it holds at 60 as long as i give it gas. is this a vacuum issue or fuel problem

 

Fuel delivery problem. Key ON, engine OFF, fuel pump running: Pressure must be 60psi to 66psi and it must remain above 55psi for at least 10 minutes after the pump shuts off. Check it like this and post the results. The drop to 20psi is a problem. Next step will be to check pressure and leakdown at the fuel filter outlet. All pressure and flow must end at the tester.

 

Checked fuel pres after filter and it does the same thing, I'm assuming this is a fuel pump check ball problem? So this week I'll get the old out and a new one in. hopefully this will fix my problem. and if not I will double check all my vacuum lines again. Is there anything else i could possibly be missing?

 

At the fuel filter outlet: All fuel pressure and fuel flow must end at the tester, (commonly called "dead head" pump pressure or maximum pump output pressure) it must be 73psi to 108psi while the pump is activated. Pressure must remain above 55psi for at least 10 minutes after the pump shuts off. If it fails one or both parts of the test, check voltage and ground at the pump module connector. If they test OK, install a genuine AC Delco or Delphi fuel pump module. Proper fuel delivery on this engine is too critical to mess with aftermarket junk, it doesn't make the grade.

 

Thanks a lot I really appreciate the help, hopefully she'll be up and running this week. i work night shift on weekends, so my only time to get things done are at the start of the week, but I'll post up what happens asap.