I HAVE A 88 FIREBIRD FORMULA, AND I AM HAVING ISSUES WITH THE FUEL PUMP NOT PRIMING...SO ANY HELP WOULD BE APPRICIATED


to be honest i am not sure...is there a way i could find out....
everything is new , fuel pump, oil sending unit, ignition switch,
i am getting power to the ecm and everything else...i am evening getting power from the ignitoin switch to the ecm but nothing coming out of the ecm to the relay ....so it would prime

 

When you turn the key from "Off" to "Run", the ECM is supposed to trigger the fuel pump relay for two seconds. I know that some trucks have a "hot fuel module" that will prime the pump for ~20 seconds, but I suspect that no F-bodies got that.

Either the relay is faulty, or the ECM is faulty, or the wire harness for the fuel pump relay is faulty. You will need a wiring diagram for your vehicle.

Test for the ECM trigger voltage at the appropriate terminal of the fuel pump relay socket when someone turns the key. You'd better have voltage there for two seconds. If you do, the problem is the relay, or wiring downstream from the relay including the fuel pump fuse.

Even if the relay has failed, the engine should get fuel pressure once the engine has cranked long enough to build oil pressure. The oil pressure switch bypasses the relay so the fuel pump will run.

 

SCHURKEY

thanks for replying back,,,but the only power i am getting on the fuel pump relay is the one from the fuse next to the battery, but nothing from the ecm when i turn the key on....there is nothing....but if i by pass the relay the pump kicks on fine but other than that there is no power from the ecm to relay...

 

Failed ECM, or
Broken wire in the harness, or perhaps the wire end in the molded-plastic connector has pulled back so it doesn't contact the terminal on the ECM.

Inspect the wire harness. If there's continuity from the relay end to the ECM end, but no continuity from the wire to ground--I'd expect the ECM has failed.

 

i check the wire on the ecm harness and its fine no breaks and tested the green/white wire for continuity and the wire is fine also....so my guess is that the ecm has failed me.....

 

yes that was the issue the ecm failed me..so i purchased a rebuilt one and changed the chips and fuel pump is running know.....

 

If I recall - you can run the fuel pump from under the hood - maybe by connecting the relay or something - that should give you enough to search on how to do this. anyway, try that and see if you fuel pump operates. if not, you've narrowed down your issue.