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MG Car Repair/78 mgb USA


car died going down road@ 40 mph will turn over ,almost fires bud will not start.pulled all plugs and turned over,they all sparked simultaneously ,did tdc with plug one and rotor was in right place when i took off distributor cap .fuel pump is working to carb no water bubbles installed new needle valve in float chamber still nothing im at a loss please help with any ideas please

Hi Phil

If your MGB was running OK and suddenly stopped this is usually a sign of an electrical problem.  (With carburation problems, the engine usually splutters and loses power before it dies).  

The car was running OK up till then, so don't mess with the timing or the mixture settings or else you will only compound the problem.

Was it a wet day?  Was there any sign of moisture getting into the distributor cap?  

Do you have points inside your USA distributor or is it electronic?  If you have points they may have closed up with wear, so check and reset the points gap.  Also, with points, it could be that the condenser is breaking down and needs replacing.

When the car died, did you hear anything such as a POP or a backfire?  I worked on one MGB that blew the rear core plug out of the back of the inlet manifold.  All the owner heard was a pop and the engine died.  It just needed a new core plug fitted and then it was fine.

Let me know what you find.

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Barrie Jones


MG Sports Cars from 1949 to 1980 - Including MGB, MGBGT V8, TF1500, TF, TD and modern Midgets. I also specialise in SU carburettors, Lucas wiring, suspension, steering & brakes.


I have owned my 1955 TF1500 since 1966. Technical specialist for the TD and TF with the MG Car Club T Register. Also owned 20 MGBs and currently own an MGBGT V8. Written 3 books on MGs and produced a DVD on how to strip and rebuild the TD/TF gearbox.

MG Car Club.

Barrie's Notes on the 1953-55 MG TF (author). /=====/ Barrie's Notes on the MGB (author). /=====/ Barrie's Notes on the MGB GT V8 (author). /=====/ The Essential Buyer's Guide to the MG TD, TF and TF1500. (author)

M Phil, C Eng, BSc (Eng).

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