Ifitaintbroke Posted April 18 Author Share Posted April 18 Personally I'm not that worried about OEM in-tank high pressure electric fuel pumps. I think they've proven their value. Aftermarket replacement in-tank electric fuel pumps are a little more questionable. It seems that there is a fair amount of junk out there, but I'm sure there are good ones as well. But for a carbed Onan generator you can't use an OEM in-tank high pressure electric fuel pump. I'm not aware of any OEM in-line low pressure electric fuel pumps (I'm well aware that there may be some I'm not aware of). And my experience with aftermarket in-line low pressure electric fuel pumps had led me to try to avoid them whenever possible as well. You just spelled it out EXACTLY. If I can avoid an electric anything I will. Link to comment Share on other sites More sharing options...
viven44 Posted April 18 Share Posted April 18 Quite a backstory. Chasing a working electric fuel pump is part of how I got my job at the parts store. Every fuel pump I put in the rear tank on the truck failed (or had a wrong resistance range-but that's another story) except a Holley. I still got so disgusted with them that I went to a mechanical pump. Looks like electric fuel pumps got you where you are I think a large part of the problem in the history of electric fuel pumps is vapor lock - high pressure in-tank pumps completely solve the problem of vapor lock by pressurizing the fuel ahead of the pump so much that vapor lock is impossible. In addition, being in-tank means little to no fuel to be vapor locked from suction - low pressure pumps in-tank are still subject to vapor lock due to the relatively lower fuel pressures ahead of them in the engine bay. - low pressure pumps away from tank are a big risk.. the long suction part is definitely a big risk for creating vacuum which is when vapor lock occurs, and the low pressure ahead is also not helpful in the engine bay heat. So far I've had success with frame mounted low-pressure fuel pumps... fancy or cheap ones.. as long as a few best practices have been followed to avoid vapor lock. (proximity to tank, mounting angle). They are cheap and easily replaceable on the road. Link to comment Share on other sites More sharing options...
Ifitaintbroke Posted April 18 Author Share Posted April 18 Looks like electric fuel pumps got you where you are I think a large part of the problem in the history of electric fuel pumps is vapor lock - high pressure in-tank pumps completely solve the problem of vapor lock by pressurizing the fuel ahead of the pump so much that vapor lock is impossible. In addition, being in-tank means little to no fuel to be vapor locked from suction - low pressure pumps in-tank are still subject to vapor lock due to the relatively lower fuel pressures ahead of them in the engine bay. - low pressure pumps away from tank are a big risk.. the long suction part is definitely a big risk for creating vacuum which is when vapor lock occurs, and the low pressure ahead is also not helpful in the engine bay heat. So far I've had success with frame mounted low-pressure fuel pumps... fancy or cheap ones.. as long as a few best practices have been followed to avoid vapor lock. (proximity to tank, mounting angle). They are cheap and easily replaceable on the road. Cheap and easily replaceable, yes. But I'd always be waiting for it to go out. Why don't we just mount the fuel tank on the hood and let it gravity feed to the carb. No pump needed! Link to comment Share on other sites More sharing options...
viven44 Posted April 19 Share Posted April 19 Cheap and easily replaceable, yes. But I'd always be waiting for it to go out. Why don't we just mount the fuel tank on the hood and let it gravity feed to the carb. No pump needed! I can understand your frame of mind. I have been soo bit by something I am never going to try it again. Like a Toyota in my case which I'm sure 99% of the people think I'm crazy but I don't care that's just what I think. Â Â Link to comment Share on other sites More sharing options...
Ifitaintbroke Posted April 19 Author Share Posted April 19 I can understand your frame of mind. I have been soo bit by something I am never going to try it again. Like a Toyota in my case which I'm sure 99% of the people think I'm crazy but I don't care that's just what I think. Â Heh. I've had some fun with a Toyota before... Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted April 19 Share Posted April 19 You just spelled it out EXACTLY. If I can avoid an electric anything I will. I have a Hudderite aunt who lives in northern Idaho. She seems to get by just fine without electricity! 💡 Link to comment Share on other sites More sharing options...
Nothing Special Posted April 19 Share Posted April 19 .... So far I've had success with frame mounted low-pressure fuel pumps... fancy or cheap ones.. as long as a few best practices have been followed to avoid vapor lock. (proximity to tank, mounting angle). They are cheap and easily replaceable on the road. That's what I had on my Bronco. But "cheap and easily replaceable on the road" is faint praise when you're stranded on the side of a freeway in afternoon rush hour on a rainy day the second time a low-pressure in-line electric fuel pump failed (at least it wasn't raining the first time it stranded me in afternoon rush hour). Now I have a mechanical fuel pump. I know they can fail too. But all three times I had one fail (and all on Chevy 350s, for what that's worth...) I could still limp it at least off the freeway if not all the way home. And those three times were all with fuel pumps that had over 100,000 miles on them. Neither of the electrics that failed on me had even 20K. But I'll repeat, I don't feel the same about the OEM in-tank high pressure pumps. I'll stick with fuel injection on my "real" cars! Link to comment Share on other sites More sharing options...
viven44 Posted April 19 Share Posted April 19 .... So far I've had success with frame mounted low-pressure fuel pumps... fancy or cheap ones.. as long as a few best practices have been followed to avoid vapor lock. (proximity to tank, mounting angle). They are cheap and easily replaceable on the road. That's what I had on my Bronco. But "cheap and easily replaceable on the road" is faint praise when you're stranded on the side of a freeway in afternoon rush hour on a rainy day the second time a low-pressure in-line electric fuel pump failed (at least it wasn't raining the first time it stranded me in afternoon rush hour). Now I have a mechanical fuel pump. I know they can fail too. But all three times I had one fail (and all on Chevy 350s, for what that's worth...) I could still limp it at least off the freeway if not all the way home. And those three times were all with fuel pumps that had over 100,000 miles on them. Neither of the electrics that failed on me had even 20K. But I'll repeat, I don't feel the same about the OEM in-tank high pressure pumps. I'll stick with fuel injection on my "real" cars! That is true. I haven't crossed that bridge so I don't know what it will take when faced what that crisis. I have nothing against mechanical pumps. The vehicles I had with a mechanical pump, they were really easy to maintain and service. No wiring to deal with, etc... as simple as it gets.. Based on what I read on the possible failure modes, I did worry about diaphragm rupture and fuel getting into the crankcase... that did worry me a bit. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted April 19 Share Posted April 19 That is true. I haven't crossed that bridge so I don't know what it will take when faced what that crisis. I have nothing against mechanical pumps. The vehicles I had with a mechanical pump, they were really easy to maintain and service. No wiring to deal with, etc... as simple as it gets.. Based on what I read on the possible failure modes, I did worry about diaphragm rupture and fuel getting into the crankcase... that did worry me a bit. When mine failed it didn't leak, it just wore the fulcrum right out of the pot metal trunnion. I was in a drive through and popped the hood, got out, took the air cleaner lid off and filled the primary bowl through the vent with a 60cc syringe. That's enough to idle for a couple of minutes, but only enough to make it to a parking spot. I was set up now, so I positioned my truck so it was easy to tow. Then I called my buddy Theo. 😉 Link to comment Share on other sites More sharing options...
Ifitaintbroke Posted April 19 Author Share Posted April 19 When mine failed it didn't leak, it just wore the fulcrum right out of the pot metal trunnion. I was in a drive through and popped the hood, got out, took the air cleaner lid off and filled the primary bowl through the vent with a 60cc syringe. That's enough to idle for a couple of minutes, but only enough to make it to a parking spot. I was set up now, so I positioned my truck so it was easy to tow. Then I called my buddy Theo. 😉 How many miles did you have on it? Link to comment Share on other sites More sharing options...
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