94 Mustang GT: Ignition

I knew that it was getting time to do the ignition in the car. It was running a little rough and I know from past experience that it was due to spark. I run an autolite 24 plug in the car since it still has the iron heads. The stock plug is an autolite 25. The 24 is one heat range colder. I figured that if I was going to do it, I was going to source everything first.

I ordered Motorcraft wires. I figured if the originals went 100k miles, these should also. I also ordered motorcraft cap and rotor for the distributor, and also picked up a Streetfire coil from my friend since he had one on the shelf. As I mentioned before, I also ordered the Autolite 24 plugs, 8 of course.

The installation is pretty straightforward. I gap my plugs for the sole reason that I have always done that. Talk to any engine builder and they will tell you that gapping is unnecessary, as long as the plug is 'good'. Remove a plug boot, remove the plug, replace with a new spark plug, change that wire with one of the same length. Plug the wire into the NEW distributor cap, in the same location. By the time you are done, all the wires are and plugs have been replaced and the wires are connected to the new distributor cap. Remove the old cap and rotor. Install the new rotor, and place the new cap (with all the wires on it) onto the distributor. Sometimes the wires are numbered, which helps if you know the firing order. Using the method above takes the guess work out of it all. While replacing the number 4 wire (passenger side, all the way in the back) I noticed that it was not seated correctly. This was probably the root cause of the car running a bit rough.

I moved on to the coil, which is a very simple remove and replace. Its right on top of the engine which makes it very easy. I also decided to check the timing. It was set at 10*, which is perfect. I started up the car, and everything worked perfectly. And it ran much smoother. I now have 17k miles on those plugs / wires. Since they are a copper plug, It may be worth it to replace them at 20k since they are only one dollar or so per plug.

This was one of the easier upgrades, and I did it for less than 60 dollars in parts, shipped to my door.

I was told that adding an MSD ignition box or equivalent may help with gas mileage. I have not yet done that, so I won't comment at this time.



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