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MG TD TF 1500 - Missfire

I have been plagued by an intermittent misfire, it can happen hot or cold no set conditions. New points, rotor, condenser, coil and dizzy cap, it still happened. I checked the plug caps when it happened Monday and found one open circuit and the others at 14/17k ohm. I ran the car without caps and all was OK.
Fitted new caps (5K ohm) and it runs sweet.
I then realised I am using resistor caps and resistor plugs, is this OK or should I forget the caps.
Ray TF 2884
Ray Lee

You'll be fine

Most later cars running resistor plug leads(carbon string) use resistor plugs

The problems arise when full wire non resistor leads are used on resistor plugs and the abundance of spark would rather travel down the outside of the plug
This is a real problem with some coil on plug cars that don't have plug leads-Running resistor plugs in them ,although spec'd for them causes terrible missfiring
Early Ford Mondeo's are well known for it

Enjoy the drive
William Revit

I use copper wire cored ignition lead with resistor plugs and caps, is this OK ?
Mind you the car is running perfectly now.
Ray Lee

Ray, unless you are concerned about radio noise, or are using an electronic ignition, I can think of no reason to use resistor spark plugs, caps, or leads in one of our cars. Why are you using them? Just curious.

I had to switch to non-copper leads when I began using a pertronix LS Igniter. Bud
Bud Krueger

I just happened to buy some cheap!
I have just read an article on a microlight site that double resistors are a no-no, they are normally OK but will fail to fire with the slightest fouling or slight richness.
Have now swapped back to non resistor plugs, the car does not feel any different but I feel more relaxed.
I use a transistor assisted points set up so use resistor caps
Ray Lee

This thread was discussed between 02/11/2017 and 03/11/2017

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