toggle switch for both Fuel Pumps???

[bert0427]

the truck I got has been totaled and caught fire before so there are a lot of wiring issues ... any way I was wanting to hook a toggle switch for the in-tank fuel pump and also a toggle switch for the one on the frame rail but I don't know if the I can just hook them up to a toggle switch or not dose any no if I can and if so how thanks for any advice, help or better ideas
1986 ford ranger 2.9l 4x4

 

[adsm08]

There is a degree of computer control on the fuel pump. It is possible to hook up a toggle, but I would do it in-line with the proper wiring, as there are other built-in safeties for the fuel pumps in the factory control system.

I'd find the wires going to the inertia switch in the cab and tap one of them for the toggle.


Anyway you cut it, probably best to find a wiring donor and start with fresh stuff.

 

[bert0427]

thanks for your input I was looking at the wiring to see if I could re wire it how it was but I only got two wires that go to the in-tank fuel pump but there is 4 slots on the connector and the pump on the frame I found the wires to it and it don't work I think it might be the relay I am going to do some tracing and see what I find ... is there suppose to be only 2 wires on the intank fuel pump ?

 

[PlumCrazy]

Sounds more like there are two wires for the sending unit and no in tank pump?

FYI if it does have both pumps, they are wired in parallel from the same feed...they always run at the same time, no need to separate supply power....

 

[adsm08]

What Plum said.

The fuel pump wiring is as follows:

PCM power relay powers up the fuel pump relay. PCM then grounds the fuel pump relay. A red (or in some years a Yellow) wire provides power to the relay's gate, then a green/yellow wire goes from the relay to the inertia switch in front of the passenger seat. A pink/black wire comes out of the inertia switch and runs as a single wire over to a plug by the brake master cylinder. On the body side of the plug the wire splits into two wires at the connector. One goes to the high pressure pump which is grounded to the frame close to the pump. The other wire goes back to the tank pump, which should have 4 wires. A pink/yellow wire for pump power, a black ground, a yellow/white wire for the fuel gauge signal, and a fourth wire, generally black and white, that is the ground for the fuel gauge.


Is that helpful?

 

[bert0427]

Thank yall for your help its awesome... but I droped the tank and there was no pump in there just a sending unit??? its a 2.9l 86 ford ranger xlt single cab... is it suppose to have a pump in tank ? the one on the frame is working I got it hooked up running constantly is that ok?
.. the only reason I though I needed a fuel pump in tank is because the truck runs smooth when it first starts but when I give it throttle it boggs down then starts skipping unless I give it throttle real slow and let it catch up with itself and I thought it was fuel pressure being low due to no pump in-tank.. I have changed Plugs, wires, coil, distributor cap, rotor button, cleaned fuel injectorsi just cant fined whats missing.. any thoughts

 

[RonD]

The pump on the frame is the high pressure pump, 40psi.
The pump in the tank was from the old carb days, 7psi.

The old stories about not running a fuel injected vehicle out of gas because they are hard to prime came from vehicles that didn't have pumps in the tank.
The pump in the tank is there to lift the fuel out, without a pump in there the high pressure pump must pull the fuel out over the top of the tank, and since it pumps liquids not air, it would have a hard time repriming, so don't run it dry

Fuel pumps run when engine runs, that is normal, so no worries.
Computer control of the fuel pump is about safety, if engine should stop running from an accident or roll over the computer cuts power to the fuel pump, when engine RPMs drop below 500, so you don't end up burning in a fuel pump fed fire.

Your slow RPM build up could be spark timing, or TPS(throttle position sensor)

Low fuel pressure, or dirty fuel filter, usually shows up at highway speeds first, so at 50mph it starts starving for fuel, but under 50 it is fine

 

[bert0427]

Thanks Ron that's good info ... I am going to check the Timing agin and TPS and I will post when I do that it might be a couple days kind of busy at work .. thanks to everyone who gave input I really appreciate it.. I will post more later