MGB failing to start

[James Fettiplace]

Dear all – I’d be grateful for some advice. I have a 1968 MGB GT.

I rebuilt the engine in the autumn. This then fired successfully and the carbs/timing were tuned such that it was idling well and it ran well for short journeys (the car is SORN). The engine then stalled suddenly and I have been unable to start it ever since.

-The HT leads, the coil and the distributor (points) are new. There is 12V at the coil.
-The car will start on 'Easy Start' before dying again.
-The engine turns well on the starter
-The compression in each cylinder is good (circa 160 in all 4)
-The fuel pumps works, there is good fuel pressure and there is fuel in the carbs – float chambers are full.

I’m at a bit of a loss. The ignition system seems to work – there is a spark and it starts with Easy start. There is fuel at the engine. The likely culprits such as the coil and dizzy are new items. It all worked before and yet now it doesn’t.

Any advice gratefully received.

Thanks, James

[David Ramsbotham]

Hi James, If the car starts on Easy start, it sounds like a fuelling issue to me. When you try to start normally and it doesn’t start then check the plugs, are they dry or wet? If dry then fuel is not getting from carbs to cylinders, that is to say your engine is not pulling in the fuel or your carbs are not allowing it to. Sometimes if inlet manifold is not correctly seating to engine this can cause fuel starvation.
If plugs are wet then fuel getting thru so check spark plugs are firing externally by earthing individually on block and cranking. If plugs sparking and fuel getting into cylinders then timing should be examined.
Hope all this is of some help, best of luck, David.

[Vic Butler]

Are the jets lowering sufficiently when the choke is operated? Presumably you're trying to start from cold. Only a thought because a few years ago I had a starting from cold problem on my BGT. It would start eventually but after a battery flattening amount of cranking and I discovered the jets on the HS6's weren't lowering fully with the choke pulled right out. A few minutes adjustment and no further problems.
. Vic Butler