mrnorm_hemicide

iTrader: (17)

Hey All,

Just installed a new Walbro 255 lph fuel pump to replace my failing pump. The install was straight forward. I plugged the new harness inline with the factory one, verified that it was getting power. Installed the feed hose and return hose, put the sock on in the same orientation. Re-installed the module, heard the pump prime and it started and idled just fine. I drove it around, and about 3 minutes later it just started sputtering and died out, like it ran out of fuel. It would crank after that but would not start. I took the pump out and verified that the hoses werent kinked, and that the wiring hadnt been damaged. The sock looked clean as a whistle, and it obviously hadnt been clogged with anything. I put the pump back in and it fired and ran again for about another 3 minutes before doing the same thing. Now it wont start at all. I can hear the pump running with the key on. I pulled the feed line off and it is flowing fuel but it doesn't seem to be coming out with any significant pressure.

I'm just wondering if anyone has ever had this issue after installing a brand new pump? I am gonna put a gage on the schrader valve and see exactly what kind of pressure I've got. Any input on this problem would be greatly appreciated. Thanks!

96silverram

iTrader: (12)

I may be wrong, but I thought there was a connector in the engine bay that you have to energize to properly prime the pump after installing a new unit? I could be wrong on this and I'm sure some other guys will jump in here and help out. Definitely check the fuel pressure; although, it is hard to believe that you would have a bad pump right out of the box.

Transmission Perform

Could be the relay that was causing your fuel pump to seem bad.

I know when mine went out i heard no pump priming i thought instantly it was a fuel pump i remembered i was hearing loud humming noises from where the relay is located which is under the driverside kick panel.


I replaced it just because it was much cheaper than a new pump and boom started. Still put a new racetronix in though just for reliability concerns.

Bigtoyz

iTrader: (2)

I would check for pressure first and then track down the relay. I drove my car 60 miles to get it dyno tuned. Stopped for the wife at menards went to fire it up and yip damn relay went bad. Just like that........I jumped the relay and pump would run.

mrnorm_hemicide

iTrader: (17)

I will certainly look into the relay, but the thing is I hear the pump running when I turn the key and when I crank it. Its definitely running, so shouldn't that rule out the relay?

whytryz28

iTrader: (28)

I just dropped my Walbro in an it started up right after, didn't even disconnect the battery haha.

mike171562

iTrader: (4)

could be the filter?

mrnorm_hemicide

iTrader: (17)

Its a legitimate point, and I intend to replace it. I had thought perhaps that the new pump may have pulled up a bunch of debris and sent it through the system, but the sock filter was completely clear. I talked to a guy at work and he said he's had nothing but bad experiences with the GM walbro pumps. He had back-to-back walbros go bad right out of the box

mrnorm_hemicide

iTrader: (17)

Update: Called the tech specialist at the company I bought the pump from. He is pretty sure I burned the pump up from lack of fuel from mounting it in the module without putting it in the factory plastic case the original one came in. I'm not sure I believe him, as this was a completely full tank of gas, but he is pretty sure. I'm gonna send the pump back to him and he'll tell me for sure, but it certaintly seems like for whatever reason the pump is shot.

Anyone else ever had an issue just ziptie-ing the pump to the bottom of the module, not within the plastic case?

mike171562

iTrader: (4)

I ziptied mine and its been working great, it shouldnt matter if its submerged in fuel

mrnorm_hemicide

iTrader: (17)

UPDATE: I sent the pump back to the supplier and bought a new Granatelli in the mean time from Summit. This time I installed it in the plastic case. The car fired, ran fine, I drove it around for quite some time pulling some g's to get the fuel sloshing around: no issues. I doubt the case had anything to do with it, but it is worth noting that the case does keep the pump constantly submerged in fuel regardless of where the tank level is.

However, I let it sit overnight and when I came out and started it again it was very hard starting, like it wanted to fire but didn't quite have enough fuel. Then when it did start and run finally it seems to be starving for fuel at high load/speed (not as bad as with the original pump). So now I'm thinking putting in a good pump has shed light on some other fuel system problems downstream.

I checked the regulator vacuum line and its dry. I'm looking at the fuel filter, and I'll see how it responds to a new one. If that doesn't address the issue I might start looking at the injectors. More to come. Thanks again for all the input guys!

mrnorm_hemicide

iTrader: (17)

FINAL UPDATE: So after the 2nd pump failed after about 4 miles of road time, I finally went back to a new GM pump and low and behold it now works like a charm, hasn't given me a single issue in days now. Needless to say this has really put a bad taste in my mouth in terms of aftermarket performance pumps. I think next time I will think good and hard about buying an aftermarket pump at all.

Thanks again for all the input everyone!

StraightTimeStirrups

Seems odd to me that you would change a Fuel Pump without also changing the Fuel Filter at the same time unless I mis-read something.

Joe

WS Sick

very strange, I have changed about a dozen pumps in 4th gens alone with and without the plastic cans and my only quick failures were the chinese pumps. I would look over your pump wiring, its possible a ground or crimp could be the culprit of quick pump burn up.