I have a 93 dakota that i have done and engine swap on, i am almost done with the swap but ran into a snag. I'm still using the V6's original wiring harness and I cannot find the fuel pump wires. I would like to run the fuel pump to a switch. I looked at the wires going to the fuel pump relay, they were: red/white, solid blue, dark green/black, and blue/white(i think). The three i found were the red and the two blues, they seem to always be hot. I could not however, find where the dark green wire is, I'm guessing that it is the ground but I can't find it, and would prefer not to cut the wire. The fuel pump worked when it was on the V6. Can someone tell me how I could just straight wire it for when i need it. The new engine is a 1975 318cid w/ 509 cam, high comp pistons, racing J heads, pace setter shorty headers, edelbrock intake and carb. Wiring is not my strong point

 

The dark green with black wire is the power feed wire. Here is the wiring diagram. If you need more you can look in the FAQ in this section. Most likly your pump is not working due to the computer is no longer being used. I would be okay to hook up to a switch inside the interior but I would sugest using the switch to power the relay to power the fuel pump. With out a relay the switch may burn up.

If the new engine Is carberated then your electric fuel pump may be to much for it. You would need a mechanical pump. Onebadakota would know if you can or cant.

 

im not worried that the pump is to much for it, i have a mechanical pump and have the fuel pressure regulator ready to keep it at about 6psi. how would you go about wiring the switch to the relay.

 

anybody?

 

connect one end of the coil of the relay to a ground and the other to a postive swich that is hot when the key is to run. So are you using the mechanical pump or eletronic. The electronics pumps put out around 100psi. And that is alot of pressure to be holding back. The electroincs use a return line. You can just not use it but you can burn up a pump by letting all the pressure build without releasing it back to the tank.

 

i agree with crazy about the fuel pressure. by the time the regulator brings it to 6psi it will be a trickle of fuel and probably burn the pump up. the mechanical pump should be able to suck fuel trough the electric one...

 

ok so can i hook up the electric pump with the return line? and i've always heard that stock fuel pumps push it at about 25psi. my buddy's firebird has a high performance one and it is pushing 90psi. but the reason i would like to run the electric one too is because it will make it easier on the engine to pick the fuel up, thus, making more ponies. but if needed, to make the mechanical pump pick up through the elec. one would i just keep it unplugged? I would like to run both pumps, I was told that would help it ALOT!

 

I went through this and I ended up taking the electric pump out of the tank because it burnt up as stated earlier. We just used the mechanical fuel pump. We found no power loss in just running the mechanical fuel pump. Most mechanical fuel pumps pump enough fuel for high hp engines.