I replaced my fuel pump with a walbro 255, reg/diagraphm and injectors after putting the 383 in, the fuel pump I had with my 350 was an aftermarket 255 lph (and i had no issues with it),

I have had the 10 amp fuel pump fuse melt on 2 occasions (the last pump never did that), obviously the walbro is drawing more current, and have had to put a 20 amp fuse in to get it home the last time.

I looked at the Racetronix site and they have a upgrade pump wiring kit for $59 but shipping to Aus is $72

Has anyone done a DIY fix for this issue (i.e. upgrade relay etc) and has info on how / what to do ? or should I just pay the $131 for the Racetronix kit ? or can you wing it with a 15 or 20 amp fuse in place ?

 

What the kits do is run a relay back by the tank off the original wiring and run a heavy duty hot wire from the battery through the new relay. That way everything still functions the same and you get lots of current to the new pump. So run a heavy wire to the rear and hook it up to a relay ( headlight sized) and hook the relay coil to the original pump wiring. You should be able to find parts locally. If not buy the kit and you still have to run a heavy wire from the battery to the rear and hook the relay to the original wiring.

 

Here is how I made a new fuel pump circuit on my 84 C4-I mounted a Cole hersee 24059bp marine type constant duty solenoid/relay(usually around $25 but amazon has some for $8.59 which is an obvious error so I ordered a couple of them). They look like a mini ford solenoid and in my opinion are better than the oem type plastic relays. I mounted mine up near the battery and ran an 8 gauge wire from the positive terminal on the back of the alternator to one of the large terminals on the solenoid. From the other large terminal on the solenoid I ran a 10 gauge wire back to the fuel pump positive terminal after cutting the oem wire. I used a 50 amp circuit breaker and a ford inertia switch mounted near the battery for the new wire as the oem circuit and oil pressure switch is now bypassed. I ran my ground wire from one of the small terminals through a toggle switch mounted in the engine compartment in case I want to shut the pump off for whatever reason. The second small terminal is wired to any ignition on source and is the "trigger" wire for the solenoid. This solenoid has a distinctive click to it when it is first energized. Does not matter which large terminal you use for your power in and power out and either small terminal can be used for your ground and trigger wires. I have used these solenoids for radiator fans too and I like them better than the plastic ones but you could certainly use for your circuit. So when you turn your ignition on now you will hear the click and then the pump humming away!!

 

Put in a relay and bigger wire. The pump will put out more and draw less current. Same with the headlights. Check the voltage drop on the lights, just a relay upgrade will get about 20% more light.

JS

 

thanks for the quick replies guys !

a couple of questions (Im not much of an auto electrician !)
do you run a constant duty solenoid because the pump is now wired on the whole time the ignition is on ?
I like the sound of a toggle switch, could also double as a anti theft device, i havent looked yet but is there a place that the wiring runs back into the cab of the car to put the toggle wiring, and where did you run the earth to ?
could you mount the solenoid, circuit break and toggle at the rear near the tank, or is this too much of an explosion risk due to fumes ?

 

You cannot run a standard momentary solenoid, it will burn out as it is not constant rated. I ran my wire along the driver side rail all the way back. I guess you could mount the solenoid and circuit breaker in back but then you would still have a live 12 volts all the way back and would still be live if the circuit breaker trips in the rear. I have the the toggle on the ground wire and you could run it into the interior and ground under the dash somewhere. I just mounted mine near the radiator shroud and grounded it to a common ground I have coming off the back of the driver cylinder head. You can also put the toggle on the trigger wire if you want to and mount it under the hood or inside, I like it under the hood.

 

ok, it sounds like mounting the solenoid and fusible link under the hood near the alternator is the better option.
do you tap into the wiring at the plug in joint at the fuel tank ?
Im thinking about mounting the toggle at the fuel cap ?

 

On the Racetronic's harness
http://www.racetronix.com/RX-C44-FPWHG-2.html
the fuse mounts to the Alt , the relay is at the rear.
You would need to rework the wiring at the existing tank connector to control the relay and then put the power output from the relay to the existing wire to the pump.

You would put the kill switch on the relay control wire ( stock pump wire ) , not the new power supply

 

i looked at that racetronix photo and thats where i got the idea you put the relay at the tank end, does it really matter which end it goes ?

the other thing is using a relay vs a constant duty solenoid ?

I was thinking about putting the toggle in the recess where you put your fuel cap when refuelling and connecting it to the earth wire.

 

You can do this a number of ways, I just reported on how I did mine. Yes I did connect the new power wire at the sending unit /fuel pump. The oem wire is not used and the fuse is removed and I guess that wire could be used as the trigger wire if you mounted the relay at the rear. Use whatever relay you want, I just shared with you what I used. 24059 much easier to wire with its studded terminals and is used in many marine and industrial applications for severe duty.

 

As I suggested earlier and the reason the kits mount the relay in the rear are so you use the original wiring to control the relay. This way the stock control logic is still in charge of when the pump runs or not. If its confusing then buy the kit. You pull the original connector off the pump and connect it to there relay connector and then hook their connector to the pump. You still have to run a hot wire they whole way from the front to the rear but they supply what you need to do this. I would also run a new ground.

 

I did some research on google and found some good examples of how its been done, this is a typical upgrade the turbo riceburner boys do, you can effectively bypass the entire stock system, the only downside is losing the ability of the pump to turn off when oil pressure is down/off (i guess that is why some people use a toggle off the earth)
Is there a simple way of keeping the oil pressure feature, such as plumbing into the wire that controls it ?

 

You don't have that.
Stock the OP switch is wired in parallel with the pump relay ,
one or both will run the pump so if the oil pressure drops , the pump will still be running off the relay controlled by the ECM
Only by deleting the pump relay and just using the OP switch could you have that feature.

Seeing you are doing custom wiring, you could run your new pump relay off the OP switch only but also have a pushbutton to power the relay and prime the system so it will start without extended cranking.
Once the engine has oil pressure, the pump will be running off the OP switch and it will automatically stop when the engine is turned off.
No need to remember to turn off a toggle switch