engine misfire

[martinbrowning]

Can you help to identify this problem on a big valve plus 2? The car starts and idles but after 10 mins approx it starts to splutter and misfire,rapidly losing power and stopping. After an hour or so it will start again and repeat itself. I have put in brand new carbs,fuel pump,distributer,coil,leads and plugs

[nebogipfel]

Couple of thoughts ......

Condenser (if you still use points) breaking down when warm?

Problem with fuel tank venting?

[nebogipfel]

repeat deleted

[nebogipfel]

and again ..... I only clicked once

[elans3]

If the car is still on a dynamo and voltage regulator, then the coil could be breaking down when it gets warm, I've experienced this before. If his is the case, then you need to check your regulator, as if this goes wrong it causes one side of the coil circuit to burn out, and give exactly the symptoms you are describing. I got through two coils before I found out......
Hope this helps
elans3

[iain.hamlton]

Worth checking the screw holding the condensor in is tight. Mine was loose for while and caused very similar symptoms.

best regards, iain

[Jason1]

Hi

Sounds to me like the plugs are fouling. Have you checked the CO reading?

Jason

[worzel]

Hi Martin

Couple of ideas-

Do you have an alarm/immobiliser fitted?. Similar problem I had was caused by the immobiliser circuit being wired into the ignition. Apparently these things don't like continuous current. Switching to the starting circuit cured things. Does your car give troulble after a certain time has elapsed since starting up ie does the distance you cover not matter if so it might be the foregoing is the problem.

Or- partial fuel line blockage- after running for a certain time debris might be building up under pressure. Switching off relieves the "logjam" only for it to recur once running again.

Regards

John

[martinbrowning]

Many thanks for your replies. In answer to your thoughts, I am running on standard dist/points, with no immobiliser and alarm, on an alternator. When the problem shows itself the fuel pump glass bowl is still full. Latest update -I have just found low compression on 3 and 4 cylinders....valve problem maybe?

Martin