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MG MGB Technical - Carb Problems?? 72 MGB

I am a novice MGB owner ( 6 months) although I had some ( limited) experience of vehicle maintenance as a lad!!

My 72 MGB has always started first time with full choke;recently I have had problems starting; when it does fire it runs is very rough, and occasionally stops.When it does finally start (after trying different chokes positions and pumping accelerator etc)the choke has normally been pushed in.

If I can keep it running, when it warms up it seems to drive OK.

I had noticed fuel pump ticking more than before.

Have diconnected fuel line prior to carb - very good flow when pump activated ( stronger than I would have expected).

Float chambers checked - needle seat / floats seem OK; no over flow when pump activated

One (vacuum) pipe to front carb was blocked - replaced

Removed vaccuum chamber/pistons / needle / blew out line from float chamber to needle seating- no obvious problems/ cleaned / replaced but no improvement

Any suggestions??

Is it likely to be fuel system - or possibly something else? ( car has electronic ignition - Lumenition??)

Also I have now got fuel leaks at base of float chambers where fuel line to needle / jet connects - is there a washer/ compression fitting at this point - when I disconnected it I think this detached itself in body of float chamber and I have damaged them when reinstalling - are these likely to be replacements from MGOC or similar?

All help would be appreciated


Nick

PS Recently (prior to problems ) choke cable was replaced by AN Other when fitting refurbished dashboard.

Nick Waite

Sounds like an ineffective choke if it runs fine when warmed up. If HSs it is easy to check the operation of the choke, it physically moves the jets down and is easy to see and/or feel even if you are on your own and pulling the choke spindle lever up from inside the engine compartment.

Fuel pump ticking more could be misleading. That would indicate overflowing (which you say it isn't) and even if slightly rich it would either start and run rich or flood with a strong smell of fuel and not be able to start again without cleaning off the plugs.
Paul Hunt

This thread was discussed between 19/10/2002 and 20/10/2002

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