Properly setting the ignition timing can help you squeeze every last bit of power out of your Fox Body’s engine. Incorrect timing can cause sluggishness, poor fuel economy or pre-ignition.
Timing that is set too low can cause slow performance and poor fuel economy. Setting timing too high can cause hard starting or pre-ignition.
The stock timing on most Fox Body Mustangs is 10 degrees before TDC (Top Dead Center). To increase performance it is common to bump up the timing to 12 or 14 degrees before TDC center.
I hadn’t set the timing on a vehicle in 25 years. I had to do a little research before diving in head first. IMaybe someone else will find this information handy too.
Tools Needed To Set Timing
(1) Induction Timing Light
I was given this old school timing light. If you don’t have a good timing light, this one on Amazon has great reviews and is around $35 Highly Rated Timing Light on Amazon
(2) Ratchet w/Extension and 1/2″ Crows Foot. Any tool that will loosen/tighten the distributor hold down bolt will work. I like the crows foot because it has multiple uses.
I found my crows foot set on Amazon. They were value priced and quality made.
(3) Paint Marker or Similar Paint
Preparation
The harmonic balancer has hash marks on it. These marks represent degrees of timing. Hash marks are used to dial in the desired timing settings.
The right edge of the thin metal pointer is used to align to the hash marks. You may find that the harmonic balancer is rusted making the hash marks difficult to read.
I used a bit of fine sandpaper to remove the rust from the harmonic balancer. I then wiped it clean with a rag and brake cleaner. To make the lines easier to see, I painted the 12 degrees BTDC mark with my blue paint marker. Then, I used my yellow paint marker to mark the 14 degrees BTDC mark. You can choose any colors that you like.
How To Set Timing
(1) Bring the engine up to operating temperature and turn off all accessories.
(2) Remove the SPOUT connector located near the distributor. DO NOT lose it!
SPOUT connectors can be found on 1986 to 1995 Mustangs. If your Mustang does not have one, skip this step.
SPOUT Location on wiring harness. (SPOUT has already been removed in the photo below)
(3) Connect your timing light to your battery and the number 1 spark plug wire. Be sure to watch out for the fan.
If you aren’t sure which plug wire is number one reference the chart below.
(4) Point the timing light at the timing pointer near the harmonic balancer. Pull the timing light’s trigger to activate the strobe light. Do an initial check of the timing.
(5) To adjust the timing use the ratchet and crows foot tool to slightly loosen the distributor’s hold down clamp.
(6) Rotate the distributor until you achieve the desired timing.
(7) Carefully, tighten the distributor hold down clamp back down.
(8) Double check the timing to ensure it didn’t move when tightening the hold down bolt.
(9) Plug the SPOUT back in.
(10) Road test the car running it through its paces. If you don’t experience pre-ingition, you may choose to go back and advance the timing further. If you do have pre-ignition go back and back the timing off a degree or two.
Adjusting the timing fine tunes your Fox Body’s engine for optimal performance. It only takes a few minutes to check and adjust timing. Do it! You will be glad you did. It is definitely a performance gain you can feel.
Additional Information
If you experience spark knock but like the performance increase from advancing the timing a higher octane fuel may help. Try a good 93 octane gasoline. I am usually not a big fan of fuel additives. But, there are some octane boosters that have been reported to help eliminate pre-ignition when running 87 or 89 octane gasoline.
If you still experience strange spark issues there are a few other things you can look at. Make sure you have a good distributor cap and rotor with brass terminals. Make sure you are running a quality set of spark plug wires. Also make sure your spark plugs are in good shape and that you are running the correct plugs.
Find this information useful?
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