Hello gentlemen! Was wanting some opinions on a electric fuel pump. I have a 1978 d100 that ive been working on. Has a 1979 360 that i believe was out of a chrysler 300. I did a backyard rebuild on it hone cylinders new rings and bearings. Has a small summit-1789 cam edelbrock rpm heads and edelbrock rpm air gap intake. Dougs headers msd ignition. Fuel tank is out of a 1985 ramcharger sending unit has a return on it. My first attempt to running engine off the tank i had the return hooked up. Had no fuel going to the carb so I unhooked the return line ran fine after that. I was wanting too replace the hard fuel lines was really wanting to run the return. Im assuming the factory style machincal fuel pump does not
pump enough to run a return. Is it worth running a electric fuel pump? I already have a holley regulator laying around. Trying to make sure fuel delivery is on point before i start dialing in the carburetor. I appreciate any suggestions.
Electric fuel pump?
- Thread starter Sam_318
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Icetech
Well-Known Member
I personally will never use an electric pump on a street car, the noise makes me nuts and they tend to die WAY more than mechanical.. (unless it's a OEM in the tank style...)
Quick question.. why do you want to run a return at all? I use a $15 amazon pump and it's been fine... they are so cheap i keep a spare in the trunk that i can swap out in 10 mins if i need to...
Quick question.. why do you want to run a return at all? I use a $15 amazon pump and it's been fine... they are so cheap i keep a spare in the trunk that i can swap out in 10 mins if i need to...
Well simply because the sending unit has a return on it already. I also hear good things about running a return figured since im replacing the lines might as well add it now.
Icetech
Well-Known Member
K was just curious, i have never run one and never had an issue.. i would just block it myself.. BUT.. i have heard guys say it helps with vapor lock.. but i have never had that happen myself..
Yeah if I would've known this tank was going in this truck i would've bought a sending unit without the return. But its a new sending unit that ive had for awhile so I cannot return or exchange, nor do I wanna spend the money on a new one. So i figured if its not hurting anything might as well hook it up.
Just use the factory Mopar fuel filter with the return made into it. It has an orifice that's like .060 in the return nipple. The factory Chrysler fuel system is sufficient for mild to moderate street builds.
There is lots of info on the site about fuel vapor issues and return line systems and modifications. A return style fuel filter is the easiest. Where is your fuel filter located?
Thats what I had on it when trying to run the return. Swapped it out for a regular fuel filter and got fuel to the carb.
Under the cab.
Then put the filter between the carburetor and pump.
Did you install the filter upside down?
That will work. Set it at 5# if you have a pressure gauge.
There's no reason in the world a stock Mopar mechanical pump will not pump enough using a factory style return filter. They came that way from the factory. If yours won't do it, then something is wrong.
Im not disagreeing with you but ive tried two brand new factory style pumps and had no luck. Not sure if its the lobe on the cam but thats also why im considering a electric pump.
Do whatchya gotta do. I'm just telling you what oughtta work. Were you putting the filter between the pump and carburetor?
Yessir
Icetech
Well-Known Member
if it's a small block it doesn't have a lobe on the cam, it has a eccentric that bolts on the end of the cam.. they don't wear like a lobe and if it was eaten through or came loose you would really know it
i assume you don't have a scope to look in there? ($20 and worth every penny)Thats how my setup was i took the hard lines with the tank from a 1985 ramcharger I had, Just bought a new filter.
Right wasnt sure what exactly it was called. It could very much be the issue i just re used what came off the engine. And the engine did appear to be sitting from the looks of it when I pulled it. And yes I do have one ill see if I can possibly get a better look on my day off.if it's a small block it doesn't have a lobe on the cam, it has a eccentric that bolts on the end of the cam.. they don't wear like a lobe and if it was eaten through or came loose you would really know it
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Icetech
Well-Known Member
it's fine to reuse them literally forever as long as they are smooth... how bad is the line from the tank to front? could possibly be sucking air?
They appeared to be i alright shape, I just sprayed some carb cleaner and used compressed air before installing.
Professor Fate
Push the button, Max...
Your pump eccentric is fine, if it wasn't, you wouldn't get fuel when you close off the return.
I'm willing to bet you're having the same issue I ran into a while back.
The fuel filter is your problem.
Many new filters (regardless of brand) cheap out and don't have the necessary restrictor in the return fitting, which kills your fuel pressure/flow.
Look into the return fitting- you *should* see a metal plate with a ~1/16" hole in it. If all you see is the filter media, then the restrictor is missing.
Fuel Return
My final solution was a 1/4" brass hose barb, which I tapped the inside bore to 1/4-20 and screwed in a brass allen screw with the proper size relief hole drilled into it.
Not so much as a hiccup since.
Good luck and let us know what you find!
I'm willing to bet you're having the same issue I ran into a while back.
The fuel filter is your problem.
Many new filters (regardless of brand) cheap out and don't have the necessary restrictor in the return fitting, which kills your fuel pressure/flow.
Look into the return fitting- you *should* see a metal plate with a ~1/16" hole in it. If all you see is the filter media, then the restrictor is missing.
Fuel Return
My final solution was a 1/4" brass hose barb, which I tapped the inside bore to 1/4-20 and screwed in a brass allen screw with the proper size relief hole drilled into it.
Not so much as a hiccup since.
Good luck and let us know what you find!
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The Carter #4594 elec pump is what you want. It is a rotary vane pump like the Holley red pump, but quieter & more reliable. With the d100, you can mount the pump behind the rear wheel. You will not hear it with the engine running. I have my pump mounted there & do not hear it.
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