3.9 Dizzy

Hello,

my dizzy cap is loose its a new one that was there since i brought the car i was woundering is the a o ring or somthing like that ment to be there because it moves from side to side as well as up and down, i do have the two clips on but they dont seem to do anything

sounds like one of three common problems:

1/ Crappy Non-Gen Dizzy Cap / Wrong cap for dizzy
2/ Crappy non-gen rotor arm or rotor arm that's damaged or not fitted properly
3/ Dizzy shaft running 'eccentric' - usually worn dizzy shaft bushes, but sometimes something 'adrift' in the assembly; think if the rotor arm tugged off badly, you can pull the advance mech out of skew....

But, answering initial Q, no there shouldn't be an O-ring or anything under it.

its only the cap that is moving so i think poss or wrong cap

no the dissy has been pulled about and the rotor arm is pushing the cap around

the cap moves when the engine is not running

the latch lugs could be stretched but very unlikely sounds more like a duff after market map

If all else fails I guess it's a case of take out the dizzy, strip it down CAREFULLY! Reassemble using new genuine Lucas arm and cap and see where you are after that.

Make sure you know and understand how to time your engine and do make sure you mark the position of the dizzy before you take it out. Make sure you have clearly marked the timing marks and you know where the timing pointer is.

Be aware that the rotor arm will move backwards when you pull the dizzy out (15 degrees I think it is - but check that) and remember that you need to align the oil pump drive as well when you put the dizzy back in.

It's really not a big job and there's nothing particularly complicated about it. It will give you the opportunity to make sure that the dizzy shaft bearings are good, that the mechanical and vac advance are both working and that the arm and cap are correctly in place. Setting the pick up air gap can be done using an ordinary piece of 80gsm plain copier paper folded in half as your feeler gauge. Make sure you don't stretch or lose the springs on the mechanical advance which is under the pick-up base plate.

I stripped my Dizzy down a couple of weeks ago. Make sure that the plastic spacer is present as this caused me no end of problems. It sits below the mechanical advance unit.

ok thanks for the advice i might try it on sunday