6 replies to this topic

[Jakeyw20]

Hi all,

Okay so my problem is that the engine is turning over but wont actually get running, you can sometimes get it running for a split second and then it will die on you.

The problem arose the in the afternoon when I had driven it the day before and it was fine, so its quite strange there is a problem at all (but then again, it is a Mini...).

Initially it wouldn't even turn over and so I have re-earthed my battery (was in a bad way) and cleaned my spark plug tips, which are very black and even have some fuel on them. I have also got my battery on charge this eveining

Obviously my engine is running too rich, is this my problem? Could I be flooding my engine when starting it somehow?

Anyone got any ideas or suggestions?

Any comments would be appreciated, cheers

[Surfbluegarage]

spark plugs being black can mean afew things normally sugests being too rich. is it a sooty black you ca wipe off with your fingers or a stickly thick black that stays if the first one its probably running too rich. dependant on which carb you have depends how you weaken the mixture. have you checked the points haent burned out/slipped? checked to see if your gettins a good spark at the plug?

[Jakeyw20]

Okay so I've just recharged my battery and tried again and it started with the choke in but only stayed running for about 2 seconds. I'm guessing this means I amGetting a good spark becuase it has started running?
Is the engine cutting out becuase something like a choke is stuck on and it is chucking fuel in and suffocating the engine? This would explain why I can start it first time and then it gets harder and harder...
Any suggestions?
Cherrrrs

[dklawson]

The choke does not throw fuel down the carb throat. The fuel is drawn out of the carb by engine vacuum through the carb venturi.

A simple test is to tip a thimble of gasoline down the carb throat and try to start the engine (no choke needed for the test). If the engine starts, runs for a few seconds, then dies, you have a fuel delivery problem. If you have an HS series SU carb, it will have a float bowl on the side of the carb body. You can remove the cover to the float bowl to check the level of fuel and to remove any sediment in the bottom of the bowl. Haynes manuals will tell you how to adjust the float position and clean the float valve itself. If you have an HIF carb with the float bowl built onto the bottom of the carb, cleaning it out and adjusting it is a bit more tricky. Again, refer to your manual.

That said, do NOT do anything to change the mixture (rich or lean) until you have completely gone through an electrical tune up. Start by adjusting the valves on the engine while cold, then fit new points and a new condenser and adjust the points. Since your plugs are carbon fouled at this time, I would fit a new set of plugs. Do not forget to gap them. Since this is a new development the timing should be close enough but it would not hurt to at least check the ignition timing once the new points and condenser are fitted. Once all that is done, see if the engine runs better/properly before even thinking of touching the mixture settings.

[Jakeyw20]

Thanks alot for the reply mate,

Have just been out on it again and looked at my points gap, it was slightly out and so have put that back. Also noticed the middle plug on the cap on the inside had its spring loaded connector missing, so replaced the cap with a spare, and Dad managed to get it running and stay on but with no power and wouldn't keep itself running.

So im thinking replacing the condenser (as it's cheap and it can apparently go without warning)?

Does that sound like a good idea or is there anything else that can be suggested?

Edited by Jakeyw20, 16 November 2011 - 08:20 PM.

[dklawson]

Start with the cheap stuff. However, don't shotgun the repair, change one thing at a time so you know what was the problem and can recognize the symptoms in the future.

You said: "Also noticed the middle plug on the cap on the inside had its spring loaded connector missing."
Are you asking about the contact inside the cap that pushes down against the rotor? If that carbon button is missing your engine certainly will have trouble running... like it won't run at all in most cases. You said you cleaned the spark plugs. With what? If you used a wire brush, they can leave metal trace marks on the ceramic which effectively short out the electricity before it can make a spark. If you used a metal brush, buy new plugs when you buy the condenser.

If you find yourself in a period of damp weather, spray the spark plug leads with WD-40 or similar and then wipe off the excess particularly if the plug wires are old. Another trick that may help is to start the engine in a dim/dark place after the sun goes down. Open the bonnet and watch the plugs, plug wires, coil and distributor cap. If you have components with failed insulation you will see a light show.

When you post next time, try and describe how the engine sounds and also tell us what you are having to do to keep the engine running. Since the engine is running with no power and doesn't want to stay running, I am suspicious that you have something failed in the ignition system and the engine may not be running on all cylinders.

[Jakeyw20]

Thanks for the help Dklawson,

I solved the problem by replacing the distributor cap, so that the engine was running, but had no power.

A freind of my Dad's suggested that the vacum cup inside the carburetor had got stuck to the outside of the shell, so I took it off and freed it up and it was fine again.

Lucky enough I never iftted the condensor I bought so I will be taking it back! Sorry for the late reply, just thought I'd up load my solution in order to potentially help others, and to let you all know what it was!

Cheers guys,

and until the next problem... haha!