30-03-2022, 09:09 AM
(This post was last modified: 30-03-2022, 09:19 AM by John Cornforth.)
Hi Graham
Piecing together all of your descriptions, I would be more inclined to suspect ignition/electrical rather than fuel.
I can only suggest you re-check the spark side of things, the possibilities below are ordered from most to least likely:
Condenser. Even new ones can be faulty, try another
Contact Breaker Points. Oil or tarnish on faces. Clean with thin card and petrol, avoid abrasive paper
LT supply to coil via ignition switch. Check with a test lamp or voltmeter.
Earth from distributor to engine block. Is the clamp firm ?
HT leads. Unscrew acorns and check, especially the king lead
Rotor Arm
When cranking, connect one HT lead to a spare sparkplug resting on the head. There should be an easily discernable spark even with a plug gap opened up to 40 thou, as the gap isn't under pressure.
If you have established a good spark and still no joy, time to re-visit the fuel supply.
Hi Graham again
Having now read your other post about distributor wear and points, I think they would be the first thing to check. The distance from the base of the cam to the tip is only about 40 thou, so it's not hard to see how a bit of spindle bush wear can have a damaging effect. The smaller the points gap, the worse this will be.
Maybe your gap closed up due to the initial bedding down of the heel on the cam ? As others have suggested, in the short term try opening up the gap to say 18 to 20 thou, and check it on all 4 lobes.
Piecing together all of your descriptions, I would be more inclined to suspect ignition/electrical rather than fuel.
I can only suggest you re-check the spark side of things, the possibilities below are ordered from most to least likely:
Condenser. Even new ones can be faulty, try another
Contact Breaker Points. Oil or tarnish on faces. Clean with thin card and petrol, avoid abrasive paper
LT supply to coil via ignition switch. Check with a test lamp or voltmeter.
Earth from distributor to engine block. Is the clamp firm ?
HT leads. Unscrew acorns and check, especially the king lead
Rotor Arm
When cranking, connect one HT lead to a spare sparkplug resting on the head. There should be an easily discernable spark even with a plug gap opened up to 40 thou, as the gap isn't under pressure.
If you have established a good spark and still no joy, time to re-visit the fuel supply.
Hi Graham again
Having now read your other post about distributor wear and points, I think they would be the first thing to check. The distance from the base of the cam to the tip is only about 40 thou, so it's not hard to see how a bit of spindle bush wear can have a damaging effect. The smaller the points gap, the worse this will be.
Maybe your gap closed up due to the initial bedding down of the heel on the cam ? As others have suggested, in the short term try opening up the gap to say 18 to 20 thou, and check it on all 4 lobes.