walbro fuel pump question

[pato]

so i finished my conversion to my 1jz in my ga70 but my fuel pump was stuffed.
a cbf doing it myself after the whole conversion so paid someone to do it, got it back everything was great for about 20kms. sitting at traffic lights. the motor started to die and stalled
found out i blew the efi fuse, replaced it and the car starts but idles real low and wont rev etc.
did a few tests and found out the the pressure is fine but fuel flow is really poor.

anywho.. i bought a walbro pump and have just been told that apparently u have to make its own earth, that u cant use the stock earth cause it has some sort of weird resistance or something.
can anyone confirm this ??
iam going to earth it by itself tomorrow and see what happens , but would anyone know what else could be the problem.

thanks
blake

[JP]

on the few walbro install's I've done (GX70, MX83 etc), I've used the factory pump earth, which is usually pop riveted to the pump bracket.

The walbro's do tend to draw a fair bit more current for some reason, could be worth measuring the voltage at the pump terminals.

With the walbro in my wagon, you can hear when the voltage drops as the pump noise changes

[pato]

hmm.
well ive just replaced the filter and the pump still primes. so iam gettin stumped.
iam going to pull the filter off again tomorrow to check it . and ill re earth it.. and ill check the voltages and see what happens i guess

[NeoNasty]

If its drawing a lot more current make sure that the +12V and the earth are upgraded.

Run a thicker cable from the battery, through a relay to the new pump. For the earth, use the same thickness cable and run ti to a clean point on the chassis. Ensure you have plenty of cable for whatever amperage it draws.

[Macross]

Unsure of the Walbro's on a A70 chasis, but on my A80 the pump fit straight in and utilised all existing wiring and has been running for a couple of months now with no issues.

[Norbie]

Ditto with my MA61, stock wiring and it's been all good for a few years now.

Having said that I believe the MA70's have a voltage drop resistor for the fuel pump which you need to bypass when installing a Walbro as they don't like running on ~9v. I'm not sure if the GA70 has the same thing but it's worth investigating.

[pato]

what would be the side effects of not doing this u recon norbie

the mechanic thinks its the fuel pressure regulator now. iam begging to get really pissed off now and any help would be appreciated

[JustCallMeOrlando]

I installed a Walbro, and it seemed to be running okay. One day I decided to check the voltage at the terminals, and it was like 10V with 14V at the battery. I replaced the 12V wiring, and gave it a nice new earth near the tank and we got up to 13V.

[Norbie]

what would be the side effects of not doing this u recon norbie

Side-effects would be low fuel pressure.

It's easy to check, just put a multimeter across the terminals of the fuel pump when it's running. You should see > 12v.

[ReQuieM]

hmmm. I've got a walbro install all stock wires and no problems. There is a power and two earths tho. One is pop riveted onto the pump braket that other goes to a little black plastic box on the back fo the bracket. Only about 1cmx1cmx2cm. So not big. I just spliced the two earths together and then connected them to the walbro. Seams fine, tho I haven't checked the voltage or anything.

Would that black box be the resistor that your refuring to? I wasn't sure what it was and wast sure if it was going to make any difference as its not in serial, seams to just be off to the side. I thought it might have been a fail safe of some kind. I can probably get a photo of my spare tonight if needed.