Stromberg carb sputtering fuel from top left hole?

PostPost by: dcmarsh » Thu Jul 20, 2017 3:14 pm

elancarbsputter.jpg and


I just rebuilt the carbs and the front carb sputters fuel out of the hole circled in red, but not when the choke is on. I was pretty precise with the float measurement. I've been reading somewhere about not using the replacement fuel bowl valves and to stick with the original stock ones, but didn't see that until after I had them back on the car.

Any thoughts?

Thanks

Dave
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PostPost by: david.g.chapman » Fri Jul 21, 2017 4:14 pm

I had this a long time ago with my Stromberg +2.

Trying to remember I think it was the inlet fuel valve to the float chamber sticking open, as you suggest.
The carb floods and pumps fuel through that hole - not a very safe scenario if the air box is off..

I would have a good look at the valve - if you can take it apart - and see if there is anything blocking it. A tiny particle can cause the problem, so have a magnified look. If there is any doubt get a new one from Gowers and Lee, Burlen fuel systems, etc.

I have not heard of good or bad new valves regarding sealing - but they may be out there.

It's worth also checking the float for leaks, and the float height.

Dave Chapman.
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PostPost by: dcmarsh » Sat Jul 22, 2017 5:29 pm

Ok will do. Thanks!

Dave
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PostPost by: miked » Sun Jul 30, 2017 7:30 am

Dave, this a long shot but a guy I met told me that he had this and eventually found he had a rouge fuel lift pump. It was relieving pressure higher than it should and overcoming the float valves. If you are on an electric fuel pump it is easier to drop a gauge in to check the pressure. Bit harder with a mech one. As I say, a long, shot but he had destroyed a block according to him before finding it. Even had the carbs rebuilt even after the rebuilt engine until he found it.
I personally had this on an Elan but it was debris from a carb guy gluing the main jets in with Araldite. A shot of Redex had lifted it and got it stuck under the needle valve

Mike
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PostPost by: dcmarsh » Sun Jul 30, 2017 1:35 pm

Fixed! Thanks to all for the help. When I pulled the front carb back off, a small piece of debris came out of the inlet pipe. Likely fuel hose, which I had replaced, but perhaps some piece drifted in. Other suggestions were a fuel pump with too high pressure but when I mentioned at a local club meeting that it was a new mechanical fuel pump from RD Engineering, everyone dismissed that as a possibility. I met Ray recently at LOG in Birmingham and indeed he knows too much to send an incorrect pump!

I have Dellortos on my 912 engine in my Elite and may try to find a Twin Cam head that can take Dellortos. That conversion from a 907 with Strombergs to the U.K. 912 with Dellortos has been bulletproof.

Thanks again to all.

Dave Marsh
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