running really bad

[hotrodder13]

i had this problem with the old dizzy, so i got a nice shiny new one it run pefect for 3 weeks now its doin the same, its hard to descirbe but if i slowly Accelerate its fine, but if i boot it, it seems sumthing is holding it back doesnt want to Accelerate at all ,and sumtimes it trys to die even if i do it at speed,

anyone got any ideas,

cheers tom

[MarkyB]

Check the piston in the carb is moving freely, and drops with an audible clunk.
Also make sure there is oil in the dashpot.

[morris minor man]

mine was running simular to that.lack of power poor running.the rotar arm was too slack.rattling about in the dizzy cap.a brand new spark plug was breaking down under load.and in side the su carb was burnt black-sutty..sounds like fuel problems

[morris minor man]

but iv bought rotar arms.that when fitted was arcing all over poor quality.have you assembled the dizzy right

[beero]

If it ran okay for 3 weeks then the same problem occurs as the old dizzy, I would say you have a different but intermittent fault. And it does sound like fuel, or lack of it to me.

[hotrodder13]

the problems at first was the electronic ign was lose inside the dizzy, so thats y i got a new one,(it was knackerd) this one had a new powermax rotar arm, the dizzy came assembled, the carb is moving freely but i will have to check the oil 2moro it had a new fuel pump a few months ago, ive not had time to set the dizzy up perfect(i had a little go) and the carb is set up correctly

cheers tom

[d_harris]

Pre-ignition under load?

[hotrodder13]

another problem is when cold, it backfires throught the carb, but when warm through the exauhst

[d_harris]

What carb do you have fitted?

[hotrodder13]

hif 44 with k&n

[bmcecosse]

You have to track it down systematically....... Start with the plugs - what colour are they ? Are the valve gaps all correct ? Can you get a compression test and post up the readings ?

[hotrodder13]

it got to the point were the car was dying when trying to set off, so i filled the dashpot up with oil and it run better but still not gud, il check everything when its not raining

[katy]

Does that distributor have a vacuum advance unit? If so, check that it's working properly and also check carefully for vacuum leaks.
Another thing to check is that the centrifugal advance in the distributor is working properly.

[bmcecosse]

He says it's a 'shiny new dizzy' ........

[hotrodder13]

brand spankin new, think its got a warrenty if thats the problem gona sort it out at the weekend

[bmcecosse]

Check the points gap - or is it electronic ?

[hotrodder13]

electronic , ive checked all the connections and the rotar arm

[katy]

Just because it's "shiny new" doesn't guarantee that it's going to work 100%. It should, but does it?