Fuel Pump 258

Hi all. I’m having fuel pump issues and want to ditch the mechanical and go electric. Is there anything I need to know about pressure or flow rate when choosing a pump? It will feed a Weber 38/38 on top of a 258 L6.

 

The Weber carbs don't like high fuel pressure, 2-4 PSI. Facet, Carter, and Mr Gasket make low-pressure fuel pumps. 15-20 gal/hr would suffice.
What issues are you having with the mechanical? With my Weber 32/38 I am using a factory pump and a fuel filter with a return port.

 

Good options. I’ll look them up. Thanks. The mechanicals function fine when working but I’m installing my third so I’m looking at options if this one doesn’t last.

 

I was having fuel issues when I rebuilt mine and added a mc2100 carb. I found a higher volume mech pump and removed the electric one did not like the noise The Holley pump forums said when I complained about the noise “ if you can heard the fuel pump you have the wrong exhaust “. lol. Well it’s a Jeep not a street rod.

 

I wonder if you could have another problem causing your pumps to go out. In my experience, mechanical pumps outlast electric ones.

Perhaps there is fine debris in your tank? Do you have a filter on the suction side, or the pressure side?

 

I'm a neanderthal. But I generally think these kinds of mods just invite a slew of new complications and potential problems.

I'd suggest investing some thought in why you've needed three mechanical fuel pumps. That ain't normal.

 

All excellent input. Thank you .
Dwins1-I to like a quiet rig.
AndyinTexas- I had not considered tank debris. I have dual tanks and should probably pull them and clean them. I have a filter on the push side. I’ll add them to the tank sides and see what I get. A lot cheaper than an Epump.

 

I have one of those glass types at the tank up on the frame rail protected from trail rash, and one just at the carb. I installed both of them when I was having fuel issues and thought it was junk in the tank. Come to find out, the standard mech pump was not able to keep up with the larger carb. That is when I discovered a mech pump that was higher volume and the issue went away. Removed the Holley Red series electric pump and never looked back.

 

standard one that gave me issues



the one I installed

 

That second one may help. I have a new mechanical on the shelf that I’m gonna use for now but I will upgrade if issues persist. My initial problem was hard starts if the Jeep sat for a while, which I was recently told may be that the old pump was slowing allowing fuel to leak back down if the Jeep sat for a week. Cracked diaphragm maybe?

 

Or a speck of crud in a check valve.

If the diaphragm is bad, beware of fuel diluting the crankcase oil.

 

quote: "My initial problem was hard starts if the Jeep sat for a while"

I have this problem also. Even if I don't drive it, I have to start it daily if I want an easy start-up. It seems odd to me because there's a certain amount of fuel in the carb bowl that can't "leak down" to the fuel pump (it would have to leak up, over and through the needle and seat). Fuel would have to be leaking out of the bowl into the intake manifold depending on the design of the carburetor. My Jeep did it with a Weber and also now, with a Motorcraft 2150.

The old Q-Jet four barrels commonly did that when plugs in the bottom leaked. The cure was epoxy. Maybe that's what my 2150 needs?

The peculiar aspect to me is, my old `48 CJ2A fires right up no matter how long it sits.

Anyway, if anyone knows the absolute cure, please share.

 

Modern fuels are more volatile and will readily evaporate out of the fuel bowl vents if sitting for more than a few days. Some carbs are worse than others. The 2G on my '69 will last a week or so and still start, but the Edelbrock four barrel on my '71 only lasts a couple days.

 

My mc2100 does that too even though I can see fuel in the glass filter. It I drive it regularly I don’t have that except for cold days. The girl is cold natured

 

...and yet my f-head will start fine after months. ???

 

It's certainly possible I'm wrong!

 

Not saying that at all. Just puzzling to me to hear of the same problem so often.

My 2002 Ford Ranger often needs to crank forever, but is fuel injected. I suspect it is the spark plugs being ready for replacement.

 

I had a similar problem with my '66 Corvette. Long cranking before starting after sitting for a week. Then super rich, black exhaust, rough running for a couple miles, etc. Turned out the power valve(s) in the bathtub-size Holley leaked and drained the contents of the float bowl(s) into the intake manifold. New power valves, problem gone.

 

A couple of quick thoughts...........
Mechanical fuel pumps:
I've been seeing a plethora of complaints about replacement pumps lately. Seems the manufacturing isn't what it used to be.

Install a filter in front of the pump. This will filter out any sediment coming out of the tank(s). Be sure to check it often, fuel pumps are "pushers" and don't have much "sucking" ability. It takes very little debris in the filter to stop the pump flow.


Electric pumps used as primary pumps should have a roll over switch installed. This keeps the pump from continuing to run if the rig is put on it's side or worse.