Section : Starting problems

1200 Mk2 will not start when hot

Posted By : Andrew Burford, 20-Dec-2005, 08:45pm

• 1200 Mk2 will not start when hot

  Posted By : William Davies, 20-Dec-2005, 10:25pm

  Hi Andrew,
  Does the car start quickly from cold, or do you have to crank for a while? If the latter, you may have a weak fuel pump with poorly seating valves. Slight fuel vaporisation is normal with 1200s, you need to spin the engine longer for hot starts as fresh fuel is pumped through. A weak pump may not be able to overcome the vaporisation.
  Check also for any grit contamination the carb's float bowl. This can find it's way into jets causing problems at certain temperatures. I've not experienced this causing hot starting problems, but I've seen it cause problems under just about every other running condition! As the temeprature changes, grit can float in and out of the jets giving frustrating intermittent problems.
  Nothing else comes to mind, presuming the car is standard with the fuel pipe around the front of the engine. If the car is running hot it would cause this kind of problem, but you would have other more alarming symptoms,
  Cheers,
  Bill.

  • 1200 Mk2 will not start when hot

    Posted By : Steve Cureton, 21-Dec-2005, 07:38pm

    Could it be a faulty choke giving a rich mixture when cold, therefore not a problem, but too rich when hot?

    • 1200 Mk2 will not start when hot

      Posted By : Chris Taylor, 22-Dec-2005, 02:13pm

      Although fuel vapourisation or a rich-ish mixture are most likely culprits, it's also worth checking all the other "general tuning" type items such as rocker clearances, points gap, plug gaps and condition, ignition timing, air filter etc.
      If in any doubt, replacing points/condensor/plugs can make a big difference. Also, unless in decent nick, rotor arm, distributor cap and HT leads also make a big difference, BUT USE GOOD QUALITY COMPONENTS!
      Make sure that you do not pump fuel into the inlet manifold by depressing the accelerator pedal while trying to start, or only open it gradually, and once! Each downward press of the pedal squirts fuel into the engine via the accelerator pump.
      Worth checking the air filter is clean and not causing a rich mixture.
      Also worth checking the idle mixture adjustment is correct as per manual (only adjustment on a Solex carb!)
      Make sure the fuel pipe does not get too close to the engine block or head, or exhaust.
      Also worth checking the engine is not overheating (difficult without a temp gauge!) which will give the symptoms you describe.

      • 1200 Mk2 will not start when hot

        Posted By : Andrew Burford, 29-Dec-2005, 09:15am

        Well I went for a run out sat the weekend and as usual started from cold (having not been started since 16th Oct) and we went for a nice run out. After about 15 miles it started to misfire then very suddenly died. I found we had petrol and tried to crank it but it would not fire. I checked the points and noticed a very poor spark so tried to adjust the gap and cleaned the spark plugs. However this did nothing and so i thought about the condensor across the distributor coil and noticed this was warm.
        
        Fortunately I was near Mick Dolphin and he bought a spare to me and we started and were on our way again.
        Hopefully this is the end of this problem and it was a coil that caused us not to start. Thinking of it I heard of similar problems with old minis.
        
        Thanks for all your suggestions and advice.
        Safe winter Motoring and Happy New Year
        Andrew