[Mgs] 79B won't start

Paul Hunt paul.hunt1 at blueyonder.co.uk
Wed Oct 26 02:06:22 MDT 2011


Can't speak for the USA but in the UK fuel doesn't go stale, I regularly 
have fuel five or six months old over winter and into spring and it starts 
and runs just fine.

Did the pump chatter away when you first turned on the ignition?  It should 
have as the carbs would probably have evaporated to dry in that time.  If 
not, then there's your answer.  Pumps with points do suffer from oxidisation 
when left unused, even new pumps come with a slip of paper saying to clean 
the points before returning the pump as faulty.

If the pump only clicked once then possibly the float valves are stuck 
closed, although I'd say that was unlikely.  Try rapping the float chamber 
with the handle of a large screwdriver or small hammer.

After cranking with the choke out without starting I'd expect it to be 
flooded, and you would get a strong smell of petrol from the exhaust when 
that happens unless outside on a windy day.  If you didn't get that, remove 
a couple of plugs after cranking a while.  They should smell strongly of 
fuel.  If there is no fuel smell it is a fuel problem.  If they are wet as 
well then it *is* flooded, you can clear that by pushing the choke home and 
cranking with the throttle fully depressed, being ready to release the 
throttle and half pull the choke when it fires.  However you should 
investigate the spark first.

Lay a plug on the block and crank and watch for spark.  If you see a spark 
check all the plugs, and if they are OK check the static timing.  However 
the plugs could be old and not sparking under compression, in which case 
they should be replaced.

If no spark it could be damp in the distributor cap - has the heater valve 
been leaking?  Is the radiator full?  Assuming standard ignition and points 
with the ignition on manually open and close the points by hand and check 
you are getting a small spark when opening them.  If not check for 12v on 
the coil +ve with them open, 6v with them closed.

PaulH.

----- Original Message ----- 
> We just got back home after 6 months away. I tried to start the MG to no
> avail (cranks well) and due to all the other things that need done haven't
> gotten back to it yet. The car started and ran fine the day we left.


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