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Leaky Fuel Pump and Weak Performance

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M

mxp01

Jedi Warrior
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All:


I have a 59 BE with a 948, SU carbs, and mechanical fuel pump. The car was tuned and given a clean bill of health in Nashville. I then drove the car to Washington DC. Since arriving the car has been smelling a little of fuel and the performance has dropped off considerably (difficulty climbing hills, doesn't like to go over 50 mph). The fuel pump is leaking. I've tried tuning the carbs and idle, but nothing seems to make a difference.


I suspect the fuel pump is the culprit, but can anyone else chime in with thoughts/advice?


Mike


Also: I live in an apartment and keep the car in a garage. I have some tools but not the major ones to help me lift the car, work under it, etc.
 
Mike, the fuel pump is not hard to rebuild - or have rebuilt. General consensus is that it is better to rebuild than replace as the new ones aren't as good. You should be able to remove the pump without lifting the car. (though a couple of jackstands and a lift are cheap at harbor freight)

If the diaphragm is torn (most likely scenario) gas will leak into the crankcase - compromising the lubricating ability of the oil, so, don't wait.

That said, how long had the car sat before you got it? and, what gas do you use? Ethanol can mess up your carb floats in a big hurry.

As I type this, tell us about your fuel tank too and whether you have filters - which can either get full and clogged or if you don't have one can allow crud to get to the pump.
 
Check your fuel lines -- make sure all the clamps are solid and the hoses are not leaking. Also check the float bowls and jet tubes on the carbs for leaks. If you see any kind of wetness or discoloration on the carburetor heat shield, the leak is there.

It's also quite possible the smell of gas and the lack of performance are two separate issues. You may want to do a compression and/or leakdown test to rule out an internal engine problem or a blown head gasket. I know when my '69 Sprite's head gasket blew, it felt like "the little engine that could" trying to get up every hill. Where 'bouts in D.C. are you located?
 
I'm in NW. The car is in Clarendon.

I've looked it all over. The only leaks are at the fuel pump - most noticeably the diaphragm.

SaxMan said:
Check your fuel lines -- make sure all the clamps are solid and the hoses are not leaking. Also check the float bowls and jet tubes on the carbs for leaks. If you see any kind of wetness or discoloration on the carburetor heat shield, the leak is there.

It's also quite possible the smell of gas and the lack of performance are two separate issues. You may want to do a compression and/or leakdown test to rule out an internal engine problem or a blown head gasket. I know when my '69 Sprite's head gasket blew, it felt like "the little engine that could" trying to get up every hill. Where 'bouts in D.C. are you located?
Click to expand...
 
See my thread titled "mechanical fuel pump" from a few months ago. Sorry, I can't figure out how o post a hyper link to the thread.
​
 
My 948 cc mechanical fuel pump is leaking, but AH Spares doesn't appear to sell rebuild kits. Nor does British Parts NW nor Moss Motors: any suggestions? Thanks, Doug
 
Interesting I wonder why None of the "usual" suppliers don't carry the rebuild kits any more??
 
it's an error on their part I think, but they have the data on what sells and for how much. these guys at "then and now" will charge about the same amount for a rebuild kit that will last another 50 years as the usual suppliers are selling reproduction fuel pumps for that last 3000 miles. I don't want to blame our suppliers for at least trying; without them the sport would be dead. getting the feedback to them before they contract with a manufacturer to supply them with another 5 years worth of bad parts is the challenge.
 
Using a mirror and flashlight, it looks the manufacturer of the fuel pump on our 948 cc BE was AC, and the identifying number was SU9810. I spoke to Then and Now earlier today but didn't have the number. If anyone has a mechanical 948-1098-1275 fuel pump lying around handy, I'd be interested in hearing what the number appears to be. THanks, Doug
 
HealeyRick said:
This fellow specializes in AC fuel pump rebuild kits: https://classicpreservation.com/fuelpumpkits.html Maybe he can help.
Click to expand...

I spoke with the gentleman that runs that "classic preservation" business when I was having my fuel pump problems. He's a really nice guy, and he could rebuild your fuel pump for you if that's what you want. I think he kind of specializes in completely restoring and making the pumps look factory new, as well as functionally restored. I ended up buying a kit from a gentleman in Australia at "classic carburetor". Once again a really nice guy with a lot of knowledge but with the exchange and shipping(which got screwed up and took a month) it ended up being close to $90 for the kit. This spring I contacted "Then and Now" for a fuel pump kit for my uncle's Alfa Duetto and talked with the gentleman there for quite awhile. Long story short, he's very knowledgeable about our fuel pumps and the shortcomings of the reproduction fuel pumps from Taiwan that are currently available. The fuel pump rebuild kit he sent me for the Alfa was superb, and he assured me the kits he has in stock for the AC pumps that came on the 948 and 1098 engines we own are made with the same quality materials and attention to detail for around $50(but don't quote me). Check out my post from earlier this year: https://www.britishcarforum.com/bcf...ical-fuel-pump&highlight=Mechanical+fuel+pump

best regards
mark
 
Mark - thanks for the suggestion for Then and Now https://www.then-now-auto.com/fuel-pumps/ . They advised that pump SU0189 was used from 1955 to 1964 (I had read it as SU9810, backwards with the mirror) and has 5 machine screws holding it together. Cost for a rebuild kit is $ 37.50 US. I'm a happy camper, and will initiate a separate thread with a title like 'source for fuel pump rebuild kits', or something equally inspiring so it'll be easier for folks to search for. Thanks again! Doug
 
Hey! Is this what they refer to as "hijacking a post?" (Kidding!)

Anyway, I was able to rebuild my fuel pump from parts removed from a new replacement pump. I was forced to swap out the internals of the pump when I found the new pump didn't quite fit onto the mounting studs. That, and some adjustments to the carbs, and no more gas smell.

I just found it amusing to see this thread still ongoing. I relocated to the Middle East and, remarkably, several carriers block access to the British Car Forum (inexplicably also Piedmont Natural Gas Company, as well), but today I was using a different carrier and, voila, here it is!

MXP
 
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