FalconZ28

I got my newly installed 383 HSR up and running, and took it around the block a few months ago.

Parked it, as the distributor needed an adjustment, as well as a few minor other things. After a few days, I tried firing it back up again, to no avail. The fuel pump quit on me. No surprise there, it's been sitting for a long time so I decided to get a Racetronix 255 LPH pump with supplementary harness.

I install the new pump and put the tank back up along with differential, only to find out that the new pump doesn't seem to be working either. In a fit of rage, I emailed the seller (Hawks 3rd Gen on eBay) and said that the pump was a lemon and to send me a replacement. After a painfully long delay of response, I received the new pump (3, perhaps 4 weeks after my initial email?) That's beside the point.

I finally installed the 3rd fuel pump today, and it makes noise but doesn't actually push any fluid. I removed the pump and put it in a 5 gallon bucket of gas, and hooked each lead to + and -....and the pump pushes huge volume. OK, great. I've eliminated the possibility that the 3rd pump is also bad. I move on to replacing the fuel relay. No change. Pump buzzes in the tank but pushes no fluid. I blow out the fuel lines to see if that's an issue. All clear there as well.

At this point, I'm out of ideas. The pump pushes NOTHING out when hooked into the wiring harness of the car, and makes the familiar buzzing noise when it primes before start. It sounds like a healthy pump, and must be getting some form of power otherwise it wouldn't make noise at all.

If there is anyone out there with ideas, or has experienced something similar, I'm all ears and would be grateful for input.

Thanks,

aliceempire

iTrader: (14)

Are you sure the pump is getting full power and has a solid ground?

Damon

You don't have any fuel in the tank for the pump to push?

FalconZ28

Haven't explicitly checked for solid grounds in the tank.

I checked all of the connections for corrosion before reassembling, and they all appeared good.

Regarding the fuel, I'd estimate I have between 4 and 5 gallons in the tank. It went in the car with between 1 and 2, and I added 3 more gallons to be certain the pump was submerged.

I think the next thing I'm going to try is hooking 12V directly into the plug that feeds the pump. If that works then it would have to be wiring related somewhere.

Damon

I think that's a good diagnostic procedure to try. Rule things out one at a time.

FRMULA88

it may be running in reverse when installed in the car.

the pump will still prime and run, but it will not push any fuel if spinning the wrong direction.

you probably cut the harness to wire the new pump and may have switched the + and ground leads to the pump.

FalconZ28

So after trails and tribulations involving diagnosis - upon close inspection of the racetronix fuel pump, I found that the wiring harness was BACKWARD from the factory. The plastic clip, which only goes in one way, had RED going to - and BLACK going to +.

Disassembly and reassembly of the harness was not difficult with a pair of pliers, only a few drops of blood spilled. I think there should be some sort of public announcement on the forum that a series of racetronix fuel pumps have been shipped from the manufacturer wired BACKWARDS. It might save someone a heck of a lot of sweat and head scratching.

Thanks for the suggestions guys - I wouldn't have inspected so closely and ultimately have found the issue if it weren't for the couple posts in this thread suggesting it.

She runs good. Currently bleeding/ flushing the old brake fluid out.

aliceempire

iTrader: (14)

Good to know. Thanks for the follow up.

Damon

Glad you nailed it. Not as easy as finding there's no gas in the tank, but hiding in plain sight nonetheless.

FRMULA88

Glad you caught that.

On a 12V automotive system the black wire is always " - " or the ground wire by convention.

Usually not a big deal unless it is on a pump or motor that needs to spin the correct direction