Problem: loss of power when heating up - clues for the cause?

[Mike K]

Hanno

If you remove the engine cover , then run the engine until it gets hot and the problem happens again. Then, remove a spark plug lead and get somebody to hold the lead near an earth approx. 5-6mm away , turn the engine over and look for a spark from the lead to earth . At least you can work out if its a weak spark problem . Mike

[cletrac (RIP)]

I'd bet on the coil. They did that quite regularly. Most people carried a spare coil.

[Richard Farrant]

No one has mentioned the condenser, they can give similar symptoms when they break down.

[Hanno Spoelstra]

Originally Posted by Richard Farrant

No one has mentioned the condenser, they can give similar symptoms when they break down.

Thanks Richard - I was just reading up on faulty condensers while I wrote my reply above.

Hanno

[Richard Farrant]

Originally Posted by Hanno Spoelstra

Thanks Richard - I was just reading up on faulty condensers while I wrote my reply above.

Hanno

Hanno,
A sure sign of a condenser failing is burnt points. They often fail when run for a certain time, then after cooling will run again. A common fault.
Also check your coil is connected the correct way around.

Richard

[Lynn Eades]

If you have to change the polarity of the coil:
I can advise that there was a thread on the Fordbarn forum where "Bubba" (Jim Linder)(a flathead dizzy specialist in the states, with the credentials) says the coil can loose 80% of it's original output capability, if it has its polarity reversed in service.

[Richard Farrant]

I should clarify, ensure the coil suits the polarity of the vehicle, there are both Negative Earth and Positive Earth coils, then ensure they are wired correctly. As has been said, the wiring reversed will reduce the output of the spark and not only that but the spark is reversed, this can cause problems in the distributor cap too.
Firstly I would go for the condenser, they fail more regularly than coils.

regards, Richard

[Hanno Spoelstra]

Thanks all for the tips!

• Coil was new Bosch 6V approx. five years ago, so unlikely to go but will check (will not be before the end of this week).
• In-line disposable fuel filter is changed regularly, but will check again.

Other options:

• What about a bad condenser?
• Distributor cap: arcing inside the bakelite parts?

Methinks the distributor has to come off for an inspection.

Hanno

[Tony Wheeler]

Originally Posted by Hanno Spoelstra

Methinks the distributor has to come off for an inspection.

Perfect opportunity to fit one of these Hanno, and forget about points and condensors forever!

Pertronix 1285LSP6.JPG

[Hanno Spoelstra]

Originally Posted by Tony Wheeler

Perfect opportunity to fit one of these Hanno, and forget about points and condensors forever!

Good "point", is this a Pertronix unit?

H.

[motto]

Good advice Tony. 'Way to go' Hanno.
Hot Spark will be cheaper than Pertronix if they have a suitable kit. Pertronix have a larger range. Look at their web sites.

David

[Tony Wheeler]

Originally Posted by Hanno Spoelstra

Good "point", is this a Pertronix unit?

Yes it's the Pertronix kit Hanno. I bought mine a while ago but haven't got around to fitting it yet.

TONY1660.JPG TONY1655.JPG img033.jpg img032.jpg

[Andy Mitchell]

Hi Hanno,

I had exactly this problem on a Fordson V8 WOT 2 a while ago ! Changed the condensor and cured the problem.

Cheers,

Andy