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MGB 1977 MGB will only run on full choke

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We're all here to learn, aren't we? I know I have increased my LBC knowledge vastly since joining this august bunch!
 
A fair downloadable PDF booklet on the HIF series carbs >HERE.<
 
I took ownership of a 1978 MGBGT last Nov. I have not had a chance for a long drive yet and have been conducting simple jobs like oil and filter change, new coolant hoses etc. However, 4 weeks ago I had the very same problem with my HIF SU carburettors. I had good spark but still decided to replace the spark plugs. I removed the fuel line from the carburettors and the fuel pump is working with plenty of fuel getting through. Checked the coil but still the same problem as you have. Only works on full choke. I purchased a full HIF SU reconditioning kit from an SU company in Sydney (yes I live in Australia!). It cost me just over Aus$200 including postage. A friend helped me refurbish all the parts in both carbys and it solved the problem. Only issue I have now is reducing idle revs below 1000 but I think that will be ok after all the new parts are properly bedded in.
 
Thanks for the reply Tiger37, I was on the verge of a rebuild kit but a couple of weeks ago I decided to give it one last try. I took the carbs apart, gave them a good clean again, reset float levels but this time I fitted a fuel regulator. I don't know if it was the reclean and reset or the fuel regulator but its running much better now, idling is good around 900 so I'm really happy now.👍
 
The SU's don't want much over three PSI fuel pressure. If there's an aftermarket pump you may have fixed the problem with the regulator.

But I guess it doesn't matter, as you now have it running better! Congrats!
 
Lavo said:
Thanks for the reply Tiger37, I was on the verge of a rebuild kit but a couple of weeks ago I decided to give it one last try. I took the carbs apart, gave them a good clean again, reset float levels but this time I fitted a fuel regulator. I don't know if it was the reclean and reset or the fuel regulator but its running much better now, idling is good around 900 so I'm really happy now.👍
Click to expand...
it is worth noting that the last full moon was March 18 which I suspect had something to do with it. :D - They can be vexing things but that is half the fun (sometimes :rolleyes2: ) - It is worth noting that if you take apart and reassemble an SU enough times you will end up with two SUs, so, you are likeley also on your way to an excellent spares collection - now get out there and drive!!!
 
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