Baffling ignition problem

[antontsar]

Hi has anyone come across the following mind bending situation. My new Lucas 35DLMB8 distributor plus new 12v coil, leads and plugs works really well on the bench - spinning the shaft around produces great sparks across all 8 plugs. When fitted into its housing and on spinning the engine over, the sparks become at best erractic to none at all.

We have spent hours trying to find out what is going on including isolating the block from all electrics other than a completely separated battery to run the starter moter and 12v to the coil.

Has anybody out there come across a similar situation?

Sincere appreciation.

[GDCobra]

When installed in the vehicle how does it behave if you take a live feed directly from the battery?
If that works OK it would point to a problem in the wiring anywhere between the battery to the coil via things like the ignition switch, fuse box and any connectors.
Possibly an alternator issue could cause the issue, maybe high output voltage spiking the system?

[ChrisJC]

Logically, what is different between the install in the car and the bench. Maybe wires?, HT leads?

Chris.

[DEVONMAN]

Have you checked the condition of the camshaft cog?