Question Regarding Ignition Wires

[dgc333]

My car developed a roughness just off idle that got progressively worse until it was a definate miss. It started right when I put a new carb on so for the past couple of weeks I was chasing that until I ruled it out.

I ruled out internal engine with a compression test so looked to the ignition. I had a new set of Moroso Blue Max spiro core wires on the shelf so I decided to give it a shot and sure enough the engine is now running great.

Now for the question; The wire I removed were Accel Super Stock 8mm Radio Suppresion wires (conventional core with out the sprial wrap), less than 5k miles on them. After I got these off I decided to check them out and the all ohm'd out in the 6-9K ohm range right where they should. My question is what could have gone wrong with these wires? Two of then runn near a header tube but have a fiberglass sleeve on them.

 

[rumblefish360]

I'm not really the best at ignition. I have a constant problem with the key wroking right, but I'm not done with the fix-its. (Read; short comings of a hack job)

The wires, even with protection sleaves, will still be subject to heat and it's problems. If everybody ohms out within it's listed ohms per foot as per the manufacture, they should be good.
Now were down to positive connections and possible fouled plugs, good grounds gone bad. (Or leads)

I have noticed the hotter a wire gets, the more resistance builds within it. This could be the case. I believe it is with my problem not to mention a hack splice on the main battery wire to car feed. Sucker will try and start once. If I fail to start the car, I may get a second shot. If not, screwdriver time.

 

[dgc333]

The resistance change with heat makes sense since the miss-firing seems to get worse as I drive the car.

The insulators on cylinder 5 & 7 that go between the header tube and the head had the color backed out of them where they touched the headers. I had purchased the Moroso wires with angled boots so I could route 5 & 7 down and under the header tube there is plenty of space around the others. We will see how it goes.

Now I just got to richen the carb back up! :\ I had gone down 4 jet sizes thinking I was running rich.

 

[fishy68]

Dave do you think it is possible they were firing through the insulators and grounding out to the headers? Did the boots look that fryed? I've had them do that before. If there is a crack in the insulation on the boot it will grow as it warms up.

 

[MoparSteve]

The wire I removed were Accel Super Stock 8mm Radio Suppresion wires (conventional core with out the sprial wrap), less than 5k miles on them.

I had the same Accel wire with the same problem. When I removed them, I noticed the heat from the headers has been killing the rubber boot at the plug end, to a point where they were almost brittle. Now I am running Taylor Thundervolt 50 with Summit protective boot sleeves. The car has never run better before. :toothy7:

 

[dgc333]

externally the wires looked fine and electrically they tested fine at room temperature. I had those fiberglass insulators on 5 & 7 to protect them. The insulators had the color cooked out of them where they were closeset to the headers.

I have been a big fan of the sprial core wires and the Accell's weren't. Normally I would not buy them but my daughter gave them to me for fathers day last year so I wasn't about to not use them.

In anycase the engine is running fine with the Mororos Blue Max wires and since these were cut to fit I was able to route 5 & 7 under the header tube so I shouldn't have issue there in the future.