Fox Body Mustang Restoration
Fox Body Mustang, 1979 to 1993 Ford mustang Restoration. This blog goes over the process of restoring Fox Body Mustangs. Fox Body Mustangs are any mustangs that were built from 1979 to 1993, although there are many similarities there also many differences through the years. This blog does discuss some of these issues.
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- HOME PAGE
- Convert 4 cylinder Mustang to V8
- 1979 Ford Mustang 4 cylinder to V8 Brake conversion
- Mustang Parts Car Demolition
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- Bro's 1988 GT Mustang
- Mustang Engine Work
- Mustang Floor Pan Replacement
- Mustang UNDERCOATING
- Bend fuel line like a pro
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- 1G to 3G Alternator Conversion
- Subframe Connector Install
- Power Steering Cooler for Autocross Competitions
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- Door Lock Replacement
- Reset Odometer Miles
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- M81 McLaren Research "Rarest Mustang Ever"
- Mustang Differential Maintenance
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- Mustang Roof and Rear Quarters sectioning
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Thursday, January 20, 2022
Sunday, July 11, 2021
Troubleshooting Electrical system
Recently I had some issues with the 1979 Ford Mustang. Engine would warm up and then it would misfire.
After contacting Holley I was able to get ohm specs on the MSD coil I had installed. I did end up replacing the coil as it failed secondary test, but after I replaced the coil with a new one I noticed the issue come back. Engine would idle fine then it would misfire after warmed up. Timing was right on, so I decided I was going to pull off the high performance ignition system and put the car back to a factory Duraspark II system and test things out.
In the last post you saw me make a coil relocation bracket which worked out great.
After installing the original harness back on and disconnecting the MSD components I installed a brand new Duraspark II Ignition Control Module and new Super Stock 12v Ignition Coil.
On first attempt to start the engine it failed. Instantly, I could tell there was no fire. First step was to check voltage at the coil. To my surprise I only had about 6 volts where I should have 12.
Ah hah, I found another problem in this old car. At this point I decided I am going to disconnect the harness for the Ignition Control Module, Distributor, and Ignition Coil.
Next test I wanted to perform was testing the male side of the connector that is connected to the harness going into the car.
I made a diagram of the plug on my old trusty Army notepad and traced back the ignition power wire to find the correct pin to test. I turned the ignition key to the run position and verified that I had just over 12 volts, which I did. This was a relief because it meant the harness leading into the car was completely fine and the source of the problem was in the engine harness. I sourced myself some terminals. That took a bit to figure out what exactly they were. Dorman makes an assortment pack, but for this plug they are called Ford Wedge Lock terminals. I found out that Summit Racing also has these terminals. No one Sells a pigtail version of the this plug, so if issues are bad you need to rebuild it.
Mustang Coil Relocation
Fabricating and making your own ignition coil mount.
Pending on your year and the modification you have done to it you may need to relocate things. Here was my solution. I've been having some issues with ignitions system, so as a troubleshooting step i figured I would rollback to the duraspark II system which was original equipment. I didn't want to remove everything for now, so I created a new mounting point for the classic style coil. Also needed to be closer to the distributor because no one had in stock the performance wires that would stretch the distance to the left hand side of he engine compartment. My solution was to create the new mounting point that allowed the coil to be closer to the distributor while still reducing heat. I made this nice aluminum bracket from spare scrap aluminum laying around in the garage.
First creating a template.