I have now set the timing and replaced the HT leads. The car is still not firing on No.3 cylinder. The plugs were new 20 miles ago and were running fine.

Any suggestions as to what else to check?

1300 x-flow, A3 cam, +90 pistons. Std Dizzy set up.

........Neil

New Dizzy Cap / rotor arm ?

dont know much about Fords but this helped on my Rover V8 when using dizzy.

Paul

edit

is the inlet valve opening on No 3

[Edited on 7/3/10 by Paul (Notts)]

are the new plugs iridium? as these dont take kindly to being wet/fould. Use ordanary pulgs until mixtures are right.

Swap no 3 spark plug with one from a cylinder that is working, if no change then check compressions, valve clearances , distibutor cap etc. Also worth squirting WD40 onto the inlet manifold/carb with the engine running, any increase in idle speed would show up an air leak

Check for wear in the distributor bearings, much more than a hint of sideways movement is too much.

Air leak on inlet manifold at no.3 cyl. \check with a rubber tube in your ear!

Neil, has it ever fired properly on Cylinder 3 since you've had it or is this something that has started happening in the last 20 miles?

Perhaps a compression check is in order ?
as perhaps there is a problem with no3

is the valve clearance correct,
push rods straight, and seated correctly

do both rockers move when the engine is running ?

regards

steve

Sticking valve or incorect clearances leaving valve open ??

Difficult really without knowing what youve done

In answer to sme of the questions:

Engine was running fine throughout the rev range. I had it ticking over while checking engine and hose temperatures after I put a new Thermostat in. Car was upto temp and running smoothly. It then cut out for no apparent reason.

I checked the plugs it is running rich but cleaned them up and put them back.

I was getting a belt off the HT leads as soon as I touched them when taking them off, so I changed them in cse they were breaking down.

I set the timing up to 6 Degrees BTDC.

I gapped points to 27 thou.

I did find a screw had come out of the Vaccum Advance bracket so put that back before sorting the timing etc.

I will move the plugs around tomorrow night to see if the problem moves and after that its Rocker off and valve clearences I guess.

The car starts and ticks over no problem but is lumpy as soon as you apply revs.

I will report back. Let me know if anything else springs to mind.

.........Neil