I'm Running a SBC with an Edelbrock 650, a stock fuel pump, all new fuel lines & a refinished tank. Sometimes the pump just seems to stop pumping. I have a clear fuel filter so I can actually see the fuel stop coming & this eventually stalls the engine. Already put on a new fuel pump, blew out the lines & made sure everything is vented properly.... I'm stuck here what else could cause this?!?! BYC
Vapor lock? Fuel pick-up in the tank blocked? (I had a Granada with a 302 that did the same thing...randomly ran out of fuel and died, then would re-start after a while. After weeks of replacing parts and chasing the problem, the culprit was found...a piece of cloth in the gas tank would float around and sometimes block the outlet, shutting off the fuel flow. After a while, it'd float away and the car would run until it happened again!) Does this only happen when it's hot? How old is your tank? Any possibility of debris in there?
Thanks Hack, we've been thinking about the same thing, as far a debris... The tank is origional '54 but was refinished & sealed inside & out. As far as engine temp goes; it dosen't seem to matter at all. When it happens the damn thing will start back up & run & pump fine... BYC
Another remote possibility is that the fuel pump drive rod could be worn enough to affect pump performance. It's rare on small block Chevys, but was a very common problem on carbureted Escorts. Using a pump gasket or plate that's too thick can create the same problem.
One way to isolate the problem would be to disconnect the tank to pump line and run a separate hose from a separate can of fuel to your pump. If you have a blockage problem. That will tell the story.
Shit!, I hope it's not that... I know what you're sayin' though. The Engine is a farly new crate motor (stock 350 long block), with only about 50 miles on it from breakin and just drivin arround the block. This issue just kinda popped up outta noware on Monday... BYC
The drive rod is real easy to replace, if that's the problem. Try Petejoe's method...run the engine out of a gas can hooked to your pump and see what happens. Now that you say it's a fresh crate motor, another idea drifts into my mind...the fuel pump drive rod is operated off of a lobe on the camshaft...if the cam was not lubed properly and broken in correctly, then the lobes will wear REAL quick! Start simple first, though...see what happens with the gas can trick and go from there.
Since the Fuel Line is New & I have 3 different Unions in there...Think it could be the pump Sucking air at times through a bad union connection? BYC
It sure sounds like a fuel pump or pickup problem. If the pickup in the tank is not correct, this will happen. As mentioned, if the fuel pump drive rod or cam eccentric is worn, this will happen. If there's debris in the pickup or if a line is kinked, same thing. If a fuel line is routed close enough to a heat source (like exhaust), a vapor lock could occur from fuel literally boiling in the fuel line and causing a bubble. I don't like mechanical fuel pumps. If you can, mount an electric pump back by the tank and I'll bet all these issues go away. Scotch~!
[ QUOTE ] Since the Fuel Line is New & I have 3 different Unions in there...Think it could be the pump Sucking air at times through a bad union connection? [/ QUOTE ] definitely... Why are you running so many unions? Was it needed to get the correct angle?? Eliminate as many as possible.
Needed the unions because we needed to use multiple pieces to get over/under & through a couple cross member & ect, just to give it a clean hidden look. Out of the pump rod issues & things like that mentioned above, would they create an issue intermitten like this one? Thanks for the help by the way guys... BYC
[ QUOTE ] I'm Running a SBC with an Edelbrock 650, a stock fuel pump, all new fuel lines [/ QUOTE ] Same set up as me and I'm having the same exact problems. I plan to toss the mechanical pump and place an electric one back by the tank as soon as I finish the metal work on my hood project.
Actually Cleatus, I have the exact same set up on another car too, It hasn't given me a lick of trouble yet...Thats kinda why I did it again, and it's fairly cheap...Guess I'll be keepin' an eye on it now... BYC
Just as an update for you guys that helped.... The Car runs fine now, turns out the fuel tank pickip line was plugged with a lot of little pieces of some kind of black crap...We Drained & filtered the gass out & cleaned & cleaned & cleaned out the tank. Blew out the lines real good, Slapped on a new fuel filter & everythings good! Thanks again for all your good suggestions! BYC
[ QUOTE ] Any possibility of debris in there? [/ QUOTE ] and Fat Hack wins! with the first response too! I was going to add another since you asked. a tight sealing gas cap without a good vent will do that too. Paul
since the debris was there in a cleaned and sealed tank-maybe you've had some gas stolen sometime recently?putting a hose in the fill kneck can shave off some of its rubber covering into the tank.........just an observation[[how did I think of that?]
[ QUOTE ] Just as an update for you guys that helped.... The Car runs fine now, turns out the fuel tank pickip line was plugged with a lot of little pieces of some kind of black crap...We Drained & filtered the gass out & cleaned & cleaned & cleaned out the tank. Blew out the lines real good, Slapped on a new fuel filter & everythings good! Thanks again for all your good suggestions! BYC [/ QUOTE ] I had a similar problem with my 55 Safari and it too was contaminated with some black crap in the tank.Turns out whoever had the car before me had the tank out for one reason or another and when they put it back in,instead of getting a new fuel sender gasket,they loaded it up with,"monkey snot"(that black silicone shit). I had another car(50 Olds)that I had installed an electric pump on(but left the stock pump in place because I didn't have a blockoff plate)and it died on me one night on the highway.It seemed to be getting gas and would start but stall out quickly.Turned out the braided fuel line had a pinhole in it and was sucking air.When it started the torque of the motor would tug at the line and open the pinhole.Couldn't see it because it was night and the braiding covered it up.I haven't run a braided line on a car since and that was nearly 40 years ago.
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