Using a stock replacement pump for an LG4, return style, Carter 6626 or whatever it is. Roughly a 350HP 350cid engine. I'm getting a high RPM bog, similar to one I had last year. I used a pressure gauge and found pressure dropping off before, so I put in this new pump, and it seemed to work ok. Parked the car for the winter, and now the bog is back.

I can't get the hose off the nipple at the carb to hook up my gauge (i'll try again in the next few days, with more... motivation), but my question is this:

Do you guys think this mech pump is suitable for this power level? Any other source of this (aside from carb itself?) I'm going to look for a kinked line and whatnot. There is a somewhat aggressive bend in the soft line from pump to carb, but I don't think it's enough to limit flow.


Thoughts?

 

Yah, I had the same problem and fought it for one whole summer. I bought one of them Carter pumps (Summit) too. I did all the tests I could and every thing checked out. By the way all the pump tests are done at low RPM's. Anyhow just before I was going to store my ride I pulled the pump inlet line and jumped the oil pressure sw. and was I ever happy when fuel came out of the line. I did not want to change out the in tank pump. I then removed the mech. pump and set it on the bench and it rattled. The pump arm pin had broken. I went to NAPA and bought a pump for a 1984 Z28 Camaro L69 and problem solved.

auggie

 

Hmm, ok, I may as well pull the pump and check it, it's all of 2 bolts. I think I may have an oil leak in that area anyway so I can hit two birds with one stone.
I had broken the pump pushrod with the stock pump before, and replaced it with an aftermarket pump pushrod. Hopefully whatever caused the previous pump pushrod to break hasn't reared its ugly head.
Thanks for the ideas.

 

You bet. Keep in touch.

Auggie

 

What is "high" RPMs? I spin to 6000 with no fuel delivery problems using that pump.

A loose oil pump will cause problems, like oil leaks and low fuel delivery.

One thing I did was use a brass-tipped, light-weight pump push rod. Kind of like valve float, reduce the weight and the fuel pump is less likely to float. It pumps on the return stroke, not the push stroke.

 

Yah, the spring does all the work.

Auggie

 

Do you have an electric pusher pump? I remember a fellow saying that under acceleration the pump couldn't pull the fuel from the tank up through the lines well enough to keep his car supplied with fuel. He said he was only running mid-low 13s when this was happening.

Might be worth looking at.

 

No electric pump, pure mechanical.
High is over 4000RPM.

A loose OIL pump?!? Or did you mean fuel pump? Yea, i'm using the brass tipped pushrod as well, I forget who made it.
I'll check the mounting of the fuel pump ASAP.

 

Oops, "Fuel Pump".