MechNARP

Ladies and germweeds,


I need some help and once again turn to the expertise of you brilliant mother$%#ers! I recently went to the track, and upon getting on track I started hearing lean popping and my AFR started acting all "catty wompus." Got her back to the pits and shut her down, checked to make sure I didn't have a vacuum leak or anything, then tried to start her again and wouldn't start. Finally figured out the fuel pump had stopped, so I had someone else crank her over, and pounded on the bottom of the fuel tank until it broke loose and started enough to get her back on the trailer. So, bad fuel pump. She was getting voltage but not turning at all when stopped, and had real low fuel pressure when it was running, so problem solved, easy, right?


Well, got her home and ordered a new fuel pump and have been having some issues. I ordered a Aeromotive Stealth 340 to replace my Deatschwerks 300. Put the new one in and won't start. Relay is clicking on when it starts cranking, and clicking off 1-2s after it stops cranking. I can't really hear it too loud when it is cranking, but then gets real loud after the engine stops, and I can feel the pump vibrating the whole time, so it would appear as if it is running, but I am seeing zero pressure the whole time. I took the feed line off and put a rubber hose on it, and there is zero fuel coming out of it. I am thinking it has to be one of 3 things. Either a) The new fuel pump is spinning backwards (I don't think this is likely, the wires going into the plug are on the correct side according to how the pump is labeled, blue positive and black negative), b) The motor is turning but the pump for one reason or other is not (also not likely I believe), or c) The pump has a gigantic air bubble in it and won't pump it through because the delP across the pump for air is so damned small.


So, I am going to try a couple of things when I get home today to try and get it running, but I was wondering if anybody on here may have some helpful suggestions? My thought is to first try and suck some fuel through the pump to see if that will prime it, and if that doesn't work, I am going to take it out again and give her power to see if I can determine if it is spinning the pump the correct direction. Anybody seen this before? Starting to **** me off that I can never seem to just throw a new part on and make **** work correctly. Please let me know.

sprx19

iTrader: (5)

I'm very curious what you figure out because I'm having similar issues where my walbro 255 as well as my stock pump turn on and hum, but won't pull fuel through the pump.

I can try it and hear the pump run and then disconnect the lines at the pump and there is nothing in the lines. I can start the car by spraying starter fluid into the intake and still nothing from the pump. The filter isn't clogged because I tried it without it. I can blow air through the lines on the pump hat. Nothing appears to be clogged.

MechNARP

So, I went ahead and tried my idea. Had a rubber tube hooked up to the fuel feed line on top of the basket, and wasn't getting any flow even though I heard the pump running, so I basically just sucked on the end of the tube until I damn nearly drank E85! I am totally health-conscious like that. But that fixed it. Had the wife crank it over right after that and sure enough, fuel came flowing out. In my case, the problem was that fuel was just not getting to the pump inlet, it was totally air locked. Makes sense that the pump needs fuel in order to create enough of a pressure differential to move more fluid. I just had to calm the EFF down and think about it for a day or so at work. So, sprx19, I would say you should try to suck fuel through the pump (without ingesting TOO much E85) with your MOUTH (or a vacuum pump would be smarter). That way you can "prime" the fuel pump and get the stupid air bubble out. If that doesn't work, you should make sure that you have it wired correctly. I haven't seen a Walboro 255, but I would imagine that it has markings for the + and - wires, make sure those are on the correct side. If I am remembering correctly, reversing the polarity will reverse the pump direction, so if it is wired backwards, it will push fuel out of the inlet. So, try that and let us know what you find sir!

sprx19

iTrader: (5)

I will try this. Thanks.