Electric Fuel Pump

[JJRJR]

Hey guys, have been out of touch for a while, hope all is well. Long story short, wasn't getting any fuel into the carb. Gary changed the brand new fuel pump for a new Holley Unit. Still no joy. Hooked up a temporary electric pump and she fired right up.

A couple questions:

1) what the hell inside the engine would make the mechanical pump not work any longer? Do I need to worry that something broke off and is now floating around my oil?
2) we're going with an electric pump rather than tear down the front of the engine to fix mechanical and put a face plate where the mechanical pump was. Any suggestions on the best pump, etc.? Regulator location? Pro/Con of mechanical and electric?

Thanks guys.

John

 

[4spd69RR]

The mechanical pump works off of the engine cam. In the front of the cam there is a lob that forces are small rod to press on the fuel pump arm. Your problem could be that the fuel pump arm is cracked, or the cam lob is worn.
I had a brand new fuel pump go bad within a week of installing it. The spring loaded arm cracked and did not apply enough pressure against the rod from the cam and my fuel pressure dropped to zero.
I would first check the fuel pump arm first before tearing into the top of the engine.

 

[JJRJR]

The mechanical pump works off of the engine cam. In the front of the cam there is a lob that forces are small rod to press on the fuel pump arm. Your problem could be that the fuel pump arm is cracked, or the cam lob is worn.
I had a brand new fuel pump go bad within a week of installing it. The spring loaded arm cracked and did not apply enough pressure against the rod from the cam and my fuel pressure dropped to zero.
I would first check the fuel pump arm first before tearing into the top of the engine.

Thanks. We are definitely not tearing the engine up. We're going to add an electric pump. Just don't understand how a brand new cam shaft and two new fuel pumps wouldn't work. I don't know, but I'm not tearing into the engine. I'm reading a lot of good about electric pumps.

Thanks again.

 

[69hemibeep]

Some of the rods have been prematurely wearing down, and fast.

 

[JJRJR]

Some of the rods have been prematurely wearing down, and fast.

Interesting. OK. Thanks very much. Any suggestions on electric. Been hearing a lot of good about a Mallory 4140 wired with a relay and with a return line (which I already have on my mechanical).

Thanks again,

John

 

[4spd69RR]

There are a lot of electic pumps out there, never used an electric pump myself so I cannot give you advise. My father-in-law always used a holley electric pump on (Dart Game) the race car and never had any issues. I think it all comes down to preference. I'm sure there are some pros and cons with holley's. I hear Mallary provides a good product. Some one on this site will definitely chim in.

 

[moparmike]

Chiming in !!! Been running Mallory pumps for a long time. Dependable AND quiet. John, if you are running a single carb, a 4110 is plenty. 110 gph and adjustable from 4 to7psi. Holley pumps are good too, just so damn noisy! Mount it as low and as close to the tank as you can. be sure to run a good filter between the tank and pump.

 

[4spd69RR]

See what did I say!! Will agree Holley's are noisy, but we could not hear it because of the open headers.

 

[moparmike]

Yeah, open headers will definately take care of the noise of the pump!! But on a street car, you don't want to hear your fuel pump growling continuously. That Mallory is super quiet.

 

[droptop]

Could be the new cam wearing off. Make sure you have some zinc in your oil. You can live without a fuel pump lobe, but if the rest of the lobes wear out, you will be tearing the complete engine down. :cents:

 

[moparmonk]

Good Evening JJRJR,
Yeah what 69HEMIBEEP said! I had the same problem. 2 bolts to remove the pump and then the fuel line and your can peak at it. Maybe someone has a core motor laying around that can supply a measurement of the push rod length that runs from the cam to the pump. As mentioned, my car just gradually lost top end power and continued to get worse. (duh, out of fuel) I guess if it were mine, it would be beneficial to know that you are not still wearing something down. Yank the rod out and run an electric if you wish but if it is wearing, get it out of there!

 

[69hemibeep]

We had this discussion awhile back and someone found a good quality replacement rod, it might have been Hugh's engines. The lack of zinc and phosphorus in oil I think is the culprit in the wear

 

[JJRJR]

Just found the hardened push rod for the pump on Hughes, only $21. The real question: does the engine have to be torn down to replace it??

Thanks,

J

 

[generaljmwlee]

Just found the hardened push rod for the pump on Hughes, only $21. The real question: does the engine have to be torn down to replace it??

Thanks,

J

I don't think so ,think there is a plug to take out to get to it . Anyone feel free to tell me if I am wrong.

 

[V269]

Nope no tear down. Just remove the fuel pump and there is a plug screwed in the block just below. Take the plug out and the push rod will fall right out through the hole. Easy as pie.

Also I have been running Carter electric fuel pumps for years and no problems with them. :yesnod:

 

[69hemibeep]

Nope no tear down. Just remove the fuel pump and there is a plug screwed in the block just below. Take the plug out and the push rod will fall right out through the hole. Easy as pie.

Also I have been running Carter electric fuel pumps for years and no problems with them. :yesnod:

:yeathat: I like the Carter rotary RV pump, its self regulated at 7 lbs. The race version requires a regulator.

 

[JJRJR]

Just ordered the Mallory Comp 4110, Regulator with return port, Mallory fuel filter (between tank and pump), block off plate and relay. That should about do it. The 4110 is preset at 7 psi, but they say all the Comp models should have regulator? I guess can't hurt. Filter was a bit pricey, but probably worth it in the long run.

Thanks,

John

 

[moparstuart]

J[/quote] get one of the big magnetic drain plugs hughes also carries
but you may have to replace the barings I had to , thought i could get by with just
changing the oil several times and using the magnet to get all the metal out but the motor didnt make it but another 2000 miles and the main barings where shot and the crank had to be turned 10/10

 

[4spd69RR]

Looks like a lot of good advise gentlemen, that is why I like this forum site!!

 

[zupanj]

I am using a Carter P74029 and it works very well. Not noisy but you can hear it if engine is off. It is set at 7 psi so a regulator is not needed. I wired it to a toggle switch with a 10 amp fuse in line. I still have my mechanical pump on the engine and a vapor separator. I don't think that is a filter as it only has a screen. I only use the electric pump if I haven't run the engine for a week or so. It primes the carbs and then I shut it off and run off of the mechanical pump.

I would not put a filter between the fuel tank and pump. That is a set up for a low pressure area at the pump inlet and potential for cavitation. If you feel the need for a filter I would put it on the pressure side of the pump or downstream somewhere.