Sprint high tension/spark plug leads

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Sprint 77

Sprint high tension/spark plug leads

#1 Post by Sprint 77 »

Hi
We have recently purchased a 76 Dolomite Sprint. When we bought it it wasn't going, starter was kicking over but not firing. After moving it on a car trailer and trying it again it fired up on 2 cylinders and idled. Pulling the plug leads off determined it is firing on 2 and 3. It had been sitting unstarted for close to 2 years and am not sure how well it was running before that. I have changed the oil, emptied the fuel and replaced it with 98 octane unleaded with some valve saver!

From what i have read and friends who have a bit of an idea we are thinking possibly the hi tension leads may be the problem. What I cant find is what range of resistance the leads should be showing when tested! I have tested using a multimeter the resistance, ohms, of the leads was 1 = 25000, 2 = 24000, 3 = 13000 and 4 = 75000, give or take a few hundred. The test was taken with the leads in the distributor cap, from the screw to the spark plug end. I believe the leads and distributor cap are original as the car only has 28000 miles on it!! Have all the paperwork from new.

So can someone tell me what resistance range the leads should have?

Sprint 77
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soe8m
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Re: Sprint high tension/spark plug leads

#2 Post by soe8m »

With a conventional ignition system you want/need about 10kOhm max and 5 kOhm as a minimum to stabilize the spark. When you look at the scope with a 0Ohm ht system all looks spikey and not consistent.

But all adds up. From the coil to the plug. You can have copper core leads and a 5Kohm coil lead or 5 kOhm ht leads etc. etc. Bosch distributors have a 5Kohm resistor in them already and all plugs with an R in them like BPR6ES have a resistor in them also There are plugcaps with inbuild resistor.

It's just matching the parts you have. I had made at magnecor many years ago some sets that had plastic plugs with 5kOhm resistor that did fit inside the sprint tube that used the original top hat to look original. The leads were 0Ohm tinned copper core from magnecor without any white text. So totally original from the outside but modern plig caps with the resistance you want.

Jeroen

I did put some on my facebook site a while ago about this but it's in Dutch.

https://nl-nl.facebook.com/classickabel ... 9723457498
Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com
Sprint 76

Re: Sprint high tension/spark plug leads

#3 Post by Sprint 76 »

Thanks Jeroen
My level of understanding with this is pretty low, but I think I will get there eventually! M y English is bad enough and I have lived with that all my life, my Dutch I have non and my Facebook not much better!!!

Alan
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