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MG MGB Technical - Which fuel pump is best for a Weber 32/36 carb?

I have a Weber 32/36 DGV carb with manual choke on my 1966 MGB-GT. I had a cheap old fuel pump that has died and needs to be replaced.

Do any of you have experience with the Carter 4070 rotary fuel pump. It is high volume (60-70 GPH) but pumps at about 4 psi. I have heard it touted as the perfect fuel pump for Weber carbs.

This doesn't exactly agree with what I read on this site in the archives and in the Weber manual. There I find a whole range of pressures recommended for Weber DGV's, from 1.5 to 3.5 psi, with 3.5 being the top recommended pressure.

Do any of you successfully use the Carter pump with a Weber 32/36 DGV? If not, what would you recommend?

Thanks for your advice, Mike
M.E. Whalen

Mike. The book "Weber Carburetors" by Pat Braden notes, on page 22, "In general, Webers should receive a maximum fuel pressure of 3.5 psi."

I have used both the factory style SU pumps and the low pressure Faucet pumps with our cars having the Weber DGV carb installed. My last installation was an SU pump as the primary fuel pump and a Faucet style pump (purchased at NAPA) as a back up pump as per the instructions on David DuBois's website. It has been working well for several years.

Les
Les Bengtson

I've never had a Weber run properly with anything more than 2.5 psi pressure. They are precise and touchy items that don't take kindly to excessive pressure. RAY
rjm RAY

Sorry to hijack this thread. I have a weber pressure question as well. I recently installed the same Weber (32-36)on my 1972 MGB-GT. I was just wondering what whould the symptoms be if the weber is recieving more then the recommeded presure?

I am very pleased with the perfomance of this new Carb.

I am using an after market electric fuel pump purchased at AutoZone. Airtex Master. Part number E8004 it states 4-6 PSI fuel delivery. I am also using a Mr Gasket Co. from O'reilly (checker) part #9710 fuel pressure regulator set at 1.5 PSI. It is adjustalbe from .5-5.5 PSI. I am not sure about the quality or accuracy of this regulator.

Here is my problem...When I shut the car down (park it) and let it set for a while, when I get back to the car I smell strong smell of fuel. Apparently the carb has flooded. It still starts but not as easily and runs a little rough for a while until the fuel clears out.

Looking for suggestions on how to remedy this problem.

I was thinking maybe I need an electiric (in-line) fuel shut-off valve that would stop any residual pressure to the carb during periods that I shut the car down, and then would open again when ignition is turned on. Is there any such fuel shut-off valves available. I haven't found a source yet.

Or is there another way I can prevent the carb from flooding upon shut down?

Thanks,
John F
John Fraioli

John,
Excessive pressure will keep the needle valve in the float bowl from closing properly. I've used 3 psi rated fuel pumps with the Weber and found it required a reduction in pressure using a pressure regulator. I would think the setting you're using should be fine if it is accurate. Check the needle valve for debris or wear and the float level.

Joe G
J. E. Guthrie

Over the past few years, the quality of the Mr. Gasket pressure regulators have gone down hill. If your problems persist, I would suggest that you purchase a regulator from Purolator. They have a good track record and when I was running a Weber side draft DCOE, I never had any problems. I ran this combination for ten years, before installing a Moss supercharger system using an SU transistorized fuel pump. If your budget allows for it, I would use this pump due to its reliability and low pressure output. RAY
rjm RAY

John. A combination vacuum gauge/fuel pressure gauge is relatively inexpensive and will verify the accuracy of your pressure regulator settings. However, as I noted, the Weber should be capable of operating at significantly higher pressures than your believe you are running. While I do not have any experience with the DCOE system, which is where Ray notes his experience lies, I do have some fairly extensive experience with the DGV carbs and have never had a problem with the standard MGB AUF 300 fuel pumps which run more than 1.5 psi fuel pressure.

My Weber carbs were either made in Italy or, the last one, in Portugal. I noticed a few years ago, the last time I needed to purchase a rebuild kit, that the rebuild kits are now made in China. The parts manager, at my local BAP store, told me the Chinese had purchased the manufacturing rights to the Weber DGV carb. I would be interested in knowing where your carb was made and whether it was a new or a used carb.

Les
Les Bengtson

Les, The Chinese have bought out the rights to Weber? What's next, Chinese pizza? And, since when did the Chinese bother to purchase the rights to anything that they manufacture. They simply copy something and sell it. RAY
rjm RAY

Les,

The Carb was manufatured in Spain. I purchased it new last Aug. Installed it in Oct. Here is a picture, it shows the fuel regulator I am using. I will try to test the presuure and see if the regualtor is accurate or not. Then I am going to install a ball valve between the regulator and the carb, and see if that stops the fuel smell and presumalbe carb flooding that is occuring during sitting after shut down. I'll just pop the hood and shut it off after I park the car.

The other possibility I am thinking is maybe the fuel tank is not vented properly or has a bad hose at the fuel seperator. I do seem to smell the fuel odor more when I open the passenger door and stick my head in the car there.

John


John Fraioli

This thread was discussed between 17/02/2011 and 22/02/2011

MG MGB Technical index

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