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ignition problems still

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sim

sim

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Ref 1958 sprite with aluminum head Spark plugs are NGK D7EA WIRES TO THE PLUGS ARE COBALT
DISTRUIBTOR IS pERTRONIX all about 2 years old less than 2 k miles on them
Replace coil ,rotor red one and distributor cap.
also the spark plugs however they were one step colder then the NGK D7EA.
Car started without any problems 2 quick trips a day apart and it started missing again.
I am now thinking the wires to the plugs not so good and need the correct plug. Do not want to replace with same.
Want something better what will work with the Pertronix.
Been thinking of using the copper wire ones and putting a metal mesh over the wire to cut the RF noise that will mess with distributor.
Or should I just go with the magnecor that Moss offers. BTW moss order taker that I talked to knows nothing. Would not even suggest the magencor
Suggestion are welcomed good bad or ugly
thanks
Sim
 
What do the existing plugs look like?
Kinda important to read them and see.
 
HI
The problem is a lot of short trips. under 4 miles
the ones that were replace were black have not looked at the last set
Thanks
Sim
 
ok just bought a Taylor universal kit wires from Summit Racing
Got lucky and talked to the order taker that has an MGB with a pertronic system on it.
I asked which wires he was using and bought those. Will let you know what happens
Sim
 
You got one that's white, the rest black, I would suspect it isn't ignition.
Unless 3 are missing so badly....

Good luck.
 
only pulled one
will remove rest when the new wires come.
It is missing has to be the wires
thanks
Sim
 
Really?


Overly rich carbs sooting up plugs.
Wrong heat range plugs.
Bad valves.
Intake leak.
Flat cam.
Broken rings.
Cracked distributor cap.

Several other things spring readily to mind.
Black plugs is generally NOT wires, but go ahead.

Get the right heat range plugs in it, lean out the carbs a bit, READ the plugs.
 
Too long a rotor throwing brass dust into the distributor when it was hitting the brass contacts to the spark plug wires. This one took a long time to solve.
 
A flat cam a possibility However when the things runs it sounds great has good power.
 
There was dust in the old rotor cap
Did buy an new rotor and cap. I am still betting on the wires.
 
If the plugs are white, lean.
Lean missfire is one end result, generally from overheated plugs, due to A) too hot a plug, and B) too lean a mixture.

One way to ascertain is to pull a plug wire off each plug while running, see if the miss goes away as you slowly increase the distance (and increase the firing voltage).

Yes, bad plug wires can be a cuse, so can dozens of other things.
Generally, plug wires work or don't, don't go for a while and missfire.

What is the resistance reading of each plug wire?
Did you run it at night with no lights and bonnet up?
See any sparks?

You gave a clue early on in this discussion.

"the spark plugs however they were one step colder then the NGK D7EA."

Then:
"The problem is a lot of short trips. under 4 miles"

Short trips require hotter than stock plugs, not colder.
They never heat up properly, will load up and give all sorts of problems.
 
Then:
"The problem is a lot of short trips. under 4 miles"

Short trips require hotter than stock plugs, not colder.
They never heat up properly, will load up and give all sorts of problems

I think is the main problem I will get some that are one step hotter
the plugs are only white cause they were not used long enough to change color
As for how rich the carbs are running < I have to pull choke till it warms half way or it just stumbles.
 
Cold operation with choke and normal running mixture can often be unrelated.

You can cover a multitude of sins with enough choke.

But when the choke comes off, then you get to see the real way it works.

Now, if your last plugs were black due to excessive choke usage, and the new ones are white due to less choke usage, mayhaps you are lean.

The real problem lies in the lack of documentation.

How much choke on the first set of plugs, heat range of plugs, and colour of plugs, did they clean up when run at speed warm?

Color of ALL the plugs on second batch, and did they show any colour at all?
Porcelain should have started turning.

You keep changing parts, you are going to have an issue finding out what isa correct.

I mean, killing a 3 ohm coil, putting in a 17 ohm Porsche coil, even for test, on a Pertronics, swapping plugs, cap, rotor, now wires, and the problem may be something else entirely.
 
all this is probable
There was only one time in the last year.
have I had this up to teamp for more than 10 minuets.
Problem is I do not have a good ohm meter to test wires. Which means I need to replace them before I can move to the next step. Which would be pulling the engine and tearing it down. been 30 years on the lower part. The head came off and replaced with an Aluminum one about 5 to 7 years ago. I guess I could remove valve cover and check rocker arm heights to rule out the flat cam issiue.
I still have not removed all plugs
I can test for vacuum leak using carb cleaner. Will still wait for new wires
 
yes wires fixed the problem only because I was forced to pull all wires to install new ones. In doing so I found #1 wire did not have a good fit the the plug. Still have the wrong plugs.
It now start easily and did make it to the store and back with out a miss fire
I now have Taylor wires and I did check OHM on old wires and new and new were just a bit less. Both were less than 1 OHM
 
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