weber 32/36-fuel pressure

[Anonymous]

howdy folks... my 32/36 is spilling fuel into the throddle plate area and flooding the engine. I checked my needle and float and both appear to be good. I called a weber dealer inquiring about a new carb, and they said that I was probably just running too much fuel pressure...... the 32/36 should have 2-4.5psi and no more...... anybody had experience with a particular pump on this carb? I've been running my regular mechanical....David SoCal

 

[jamyers]

howdy folks... my 32/36 is spilling fuel into the throddle plate area and flooding the engine. I checked my needle and float and both appear to be good. I called a weber dealer inquiring about a new carb, and they said that I was probably just running too much fuel pressure...... the 32/36 should have 2-4.5psi and no more...... anybody had experience with a particular pump on this carb? I've been running my regular mechanical....David SoCal

Sigh...my experience with Weber dealers and mechanics is that they seem to think any problem is either fuel pressure or float height, regardless of what's actually going on. :x So I don't ask them anything, and I'm a lot happier for it.

I ran mine for a year with a stock mechanical pump. I did lower the float height way below specs to solve the "left-turn-stumble" issue with my sideways mounted 32/36.

But no issues with overpowering the float like you've got. Might try a needle / seat from a Ford 5200 (same carb). Might have a smaller seat or something, but I'm just guessing.

Edit: I think the stock mechanical pump is right at 4 psi. Anybody confirm/deny that?

 

[66 Fastback]

I would have to check my notes to see if I did write it down, but I think my stock pump put out 5 psi or more. I ran it for a several years that way. Last year in pursuit of higher mpg, I installed a fuel pressure regulator. At the same time I also made some jetting changes, but I picked up a few mpg.
Doug

 

[mcmillal]

David, When I was running with my 32/36 I was using a fuel regulator to reduce the fuel pressure. The stock fuel pump was putting out 6 1/2 to 7 psi. The regulator is cheap, adjustable, and really easy to install.

.............Cheers, Alex

 

[cfmustang]

I ran mine without one for years, but added one last Summer when I was having a slight problem with being too rich in one particular circumstance (mainly, shutting down the car warm and then restarting it). In that specific case, it seemed to help solve that problem. However, that was a minor problem and did not really see any difference in any other way.

Contrary to all the advice out there, I do not see them as a required accessory in our case.

 

[powerband]

howdy folks... my 32/36 is spilling fuel into the throddle plate area and flooding the engine. I checked my needle and float and both appear to be good. I called a weber dealer inquiring about a new carb, and they said that I was probably just running too much fuel pressure...... the 32/36 should have 2-4.5psi and no more...... anybody had experience with a particular pump on this carb? I've been running my regular mechanical....David SoCal

I also was told this by a Pro-race Holley builder. He was practical and recommended a cheap pressure regulator. I picked up a Mr. Gasket regulator at an auto box-seller store for @ $ 25.oo . Be sure to get the "low" pressure type for mechanical pumps not the higher FI type.

I played with a Vac/Fuel Press. guage with the mechanical pump. The pump would pick up more pressure under high RPM. That may be the problem , especially when the engine is under "acceleration" .

Powerband

8)

 

[Anonymous]

thanks, the regulator did solve the problem..... david

 

[xctasy]

The reason is that Ford made two types of carb, and the US style Pinto 2000 version without a return line (bleadoff line) came on a car with 4.5 psi fuel pressure. It leaked fuel in roll-overs, and had hot fuel handling (vapur lock) problems in hot conditions. The European type approval banned it from 1973, so Weber regiged that European 32/36 carb, and added a return line, aka 1983 Mustang 4-bbl, and the problems were solved. The US Holley Weber is just a pre 1973 Weber 32/36, with a few mods. Imported new 32/36's don't have return lines, and look to be based on the earlier casting.

The stock fuel pressure with stock fuel pump went down from 4.5 to the recommended 3.5 max for Webers.

Ford Australia did the same thing in 1973 on there Pinto engined Cortinas, and again in 1983 on the XE Falcon with Weber ADM 34. It got a return line on the stock Carter fuel pump to reduce pump pressure from about 5 to 6 pounds, to less than 3.5 psi.

In America, everyone it seams universally hates return lines. Hence six cylinder Fords with stock I6 fuel pumps and Webers just need a fuel pressure regulator which doesn't hurt volume to the carb. The benefit is

1) that the float won't surge, and

2)you have the choice of runing the float level at any one of the two recomendatios Weber used, 41 mms or 35, depending on how its measured.

3) Fuel economy on rough roads improves.

4) Cavitation due to hot fuel handling is reduced.

 

[66 Fastback]

Your are a wealth of knowledge!
Doug

 

[xctasy]

Brilliance is all about not revealing your export sources! So I don't get a swelled head....

When you know what cars are like stock, what they are like modified, and how a properly engineered modification should work, you get to know it pretty well. I used to hang out in car wreckers yards a lot too

Hence all of my knowledge is stollen from Aussie Wheels magazines (Oz market production cars with consistant and full testing of every facet of amost every car ever sold in Australia) and Street Machine (anecdotal reporting of almost 100% customised Aussie , American and British cars) and David Vizard books (fanatically analysed and practically explained by typical theoretical Pom who lived on the bones of his ass and then got his hands dirty on gareden variety British and Yank iron engines).

Looking at Autodatas information memos allows you to get most details online

Incidently, Vizard felt the stock 2000 cc OHC's 5200 or 32/36 carb was a good piece of work. Perhaps because the US 5200 is a little bit better than the stock pre 1973 32/36 Weber, he made no mention of fuel pressure except to say that reducing the pressure was a good idea in several books, and he cited fuel consumption. I found that Pat Braden said that Eurpeans ran low pressures, so that was important, and whenI found the changes Ford made on other markets outside the US, I solved the Weber problem, bacause someone else (Ford and Weber engineers over two continents) verified the rest.