switched fuel pump

[badnewsranger]

Is it possible to override truck fuel pump relay and inertia switch and what not and run fuel pumps off a fused toggle switch and relay or will this mess with the pump pulse for less fuel at idle and more fuel while on gas as needed if anyone has done this with no problems what all did you use

 

[IMenriched]

Is it possible to override truck fuel pump relay and inertia switch and what not and run fuel pumps off a fused toggle switch and relay or will this mess with the pump pulse for less fuel at idle and more fuel while on gas as needed if anyone has done this with no problems what all did you use

Yeah you can do it...in a pinch. the pump will stay on and likely shorten its life...another did in a emergency http://www.therangerstation.com/forums/showthread.php?t=77941

 

[valsound]

Near your EEC & fuel pump relays is the test plug.

If you ground this fellow (see photo), your pumps will operate whenever the ignition switch is in the run position.

While it's true you probably don't want to use this as a permanent solution, it's a great get it home solution.

 

[Psychopete]

Near your EEC & fuel pump relays is the test plug.

If you ground this fellow (see photo), your pumps will operate whenever the ignition switch is in the run position.

While it's true you probably don't want to use this as a permanent solution, it's a great get it home solution.

Definitely good info to know! May work for the OP, but still uses the FP relay and inertia swtich, that ground just supplements the computer grounding the relay from pin #22.

badnewsranger - either the pump is on or off - what regulates the pressure is the fuel pressure regulator, and vac is used to fine adjust and fuel is returned back to the tank. Pressure needs to be right/maintained because the injectors atomize the fuel going into the cylinders.

Follow the power wire from the secondary (frame mounted) pump up to near the dash plugs by the driver's side firewall. My '88 had a single wire connector buried in there that was the power strait to the fuel pumps. Here you could bypass both the relay and inertia switch by feeding the pumps direct power. If you use this, be sure to use fused power and a relay so that nothing gets burnt up.

Used that connection on my V8 swap and retained the stock pumps with an adjustable return style regulator to a carb.

IMO, should diagnose what is wrong, hooking up the connection on the diagnostic connector as shown above is a good starting point to figuring out what is wrong with the factory circuit (because the computer only primes when you first turn the key on, this would keep the circuit live all of the time when the key on). Just need to find where voltage isn't and work back. Inertia switch would be a good place to start..

Pete

 

[valsound]

Definitely good info to know! May work for the OP, but still uses the FP relay and inertia swtich, that ground just supplements the computer grounding the relay from pin #22.

Sorry for the hyjack, but Pete, could you help me:

On my 86 2.9 using this ground in the test plug is the only thing that keeps my motor running.

So what you're saying if I were to test between pin #22 on the computer connection and the ground pin at the fuel pump relay, I would get no continuity? Thanks.

 

[badnewsranger]

fixed

thanks for the help but i ended up finding out hat the ecm was bad put new one out of b2 in a everything works like new just sucks it took two weeks to figure out but on a good note i now have new relay, ignition module, inertia switch , eec relay, and ecm so i pray i'll be good for a while but thanks for the info

 

[Psychopete]

So what you're saying if I were to test between pin #22 on the computer connection and the ground pin at the fuel pump relay, I would get no continuity?

Possibility - but like what you found, the computer wasn't doing it for some reason or maybe the pin wasn't making a good connection(?), but either way glad that you have it figured out.