96 replies to this topic

[robnjen]

Hi - newbie here (new to this forum) but at 53 yrs old, not newbie to much!!! I have read through this thread and bells are ringing here as I have had a similar problem some time ago and it turned out to be a combination of two things - that's what makes it hard to diagnose sometimes.

I cannot guarantee that this is your problem, but it's worth a look. My first problem was the LT wiring to the coil. One of the wires was kinked at the spade connector and several of the small wires that make up the inside of the LT cable had broken, leaving just a couple hanging on. The voltage / current could not pass correctly as some resistance was being encountered. I found this on a very dark night out in the countryside where there were no streetlights - the faintest spark was appearing at the LT connection to the coil - impossible to see in any form of light, but just visible in total darkness.

The other problem I had was an air leak at the distributor cap - a new one, but not well sealed - this affected the vacuum advance at the distributor - I had no replacement but found a tube of hermetite gasket goo and ran that round the base of the cap and flew home.

The idling problems had caused excess fuel build up and all sorts of problems, but rewiring the LT cables at the coil and sealing the distributor cap fixed the idling issue - hope you sort it out.

[JakeJakeJake]

Hi - newbie here (new to this forum) but at 53 yrs old, not newbie to much!!! I have read through this thread and bells are ringing here as I have had a similar problem some time ago and it turned out to be a combination of two things - that's what makes it hard to diagnose sometimes.

I cannot guarantee that this is your problem, but it's worth a look. My first problem was the LT wiring to the coil. One of the wires was kinked at the spade connector and several of the small wires that make up the inside of the LT cable had broken, leaving just a couple hanging on. The voltage / current could not pass correctly as some resistance was being encountered. I found this on a very dark night out in the countryside where there were no streetlights - the faintest spark was appearing at the LT connection to the coil - impossible to see in any form of light, but just visible in total darkness.

The other problem I had was an air leak at the distributor cap - a new one, but not well sealed - this affected the vacuum advance at the distributor - I had no replacement but found a tube of hermetite gasket goo and ran that round the base of the cap and flew home.

The idling problems had caused excess fuel build up and all sorts of problems, but rewiring the LT cables at the coil and sealing the distributor cap fixed the idling issue - hope you sort it out.

Thanks for the ideas, however I don't think it is the LT coil leads as if I connect a HT lead to a spark plug out side the block it seems to spark fine. Will check the voltage across the coil just in case and try to test the resistance of the LT wires, see if I find anything.

I don't have vacuum advancing ignition is all mechanical so that won't be it.


Took the carb apart and found this in the float chamber plate



Might not be anything though.

I am also going to try some fresh fuel as the problems did seem to start around the same time as I filled up (fitted almost £30 in! must have been empty), this is most likely coincidental and probably will come to nothing but won't hurt to try.

[samsfern]

i get my sparkling plugs from the motor factors, i get a set of 4 for less than £5, but i do get trade discount.

[JakeJakeJake]

Removing spark plugs 2 and 3 makes no difference to engine running. Tried different spark plugs in each and it made no difference, bearing in mind HT leads, dizzy cap and most of the ignition parts are new and having just done a compression test that showed 180 psi on every cylinder, what is the problem?

[pikey7]

dunno if you mentioned it, and cba to read the other 4 pages to find out... what leccy dizzy do you have?

[JakeJakeJake]

Converted from a 45D with a accuspark kit, problem started before conversion.

[samsfern]

have you put the leads on the right order?

[pikey7]

sure you've got 2&3 connected the right way round?

Have you got / can you get another dizzy to try?

[JakeJakeJake]

have you put the leads on the right order?

sure you've got 2&3 connected the right way round?

Have you got / can you get another dizzy to try?

Definitely the right way rough checked many times, also swapped them over just to be sure

Trying a new distributor was my next idea, seems strange though for it to fail on 2 and 3 though?

[pikey7]

possibly an out of round cap, or a dodgy bearing resulting in a weak spark.

[JakeJakeJake]

possibly an out of round cap, or a dodgy bearing resulting in a weak spark.

Could be the cap, but I the problem started before I changed it.

Dodgy bearing?

[pikey7]

The bushes inside the dizzy. If they are shot the arm may not run correctly.

[JakeJakeJake]

The bushes inside the dizzy. If they are shot the arm may not run correctly.

OK cheers, will defiantly try another dizzy, or take apart my current one.

[Mr. Bridger]

I've currently got what sounds like a very similar issue so I'd be interested to know if you found the cause of your problem.

[JakeJakeJake]

tried swapping plugs 2 and 3 with 1 and 4, this made no difference. Also wired up coil LT circuits again, which also made no difference.

Ordered a new distributor on the 24th, just waiting for it to arrive.