Foxbody Mustang Ignition & Fuel System
The factory DuraSpark I and DuraSpark II ignition systems used on the late model Foxbody Mustang was actually an excellent ignition system for the time. Read below for all the information you need regarding the ignition and fuel system on Foxbody Mustangs. HO firing order, ignition timing, spark plug gap, fuel pump and injector specifications, it's all below.
Ford 5.0 V8 Cylinder Location
Ford V8 Firing Order
Foxbody Mustang Spark Plugs
Foxbody Mustang Fuel Pumps
Ford Fuel Injector specifications
1979-1985 Foxbody Mustang Ignition Timing
1986-1993 Foxbody Mustang Ignition Timing
1979-1993 Ford V8 Cylinder Banks (facing engine head on)
Left Bank | Right Bank
4 | 8
3 | 7
2 | 6
1 | 5
1979-1993 Ford V8 Firing Order
1979-93 truck V8's (non-HO) and 4.2 L V8: 1-5-4-2-6-3-7-8
1982-93 5.0 L HO V8: 1-3-7-2-6-5-4-8
| Year | Engine | Part Number | Gap |
|---|---|---|---|
| 1979 | 5.0 L 5.0 L (California) |
ASF-52 ASF-52-6 |
0.050 in 0.060 in |
| 1980 | 4.2 L | ASF-42 | 0.050 in |
| 1981 | 4.2 L | ASF-42 | 0.050 in |
| 1982 | 4.2 L | ASF-52 | 0.050 in |
| 1983-85 | 5.0 L 4bbl 5.0 L CFI |
ASF-42 ASF-52 |
0.044 in 0.050 in |
| 1986 | 5.0 L HO | AWSF-52/44 | 0.050 in |
| 1987-93 | 5.0 L HO | ASF-42 | 0.054 in |
| 1993 | GT40 Cobra | AWSF-42C | 0.050 in |
1979-1993 V8 Foxbody Mustang Fuel Pumps (factory)
Carburated Mustang (mechanical fuel pump): 1979:6.5 psi, 1982:8.5 psi
CFI Mustang: twin electric: 60 lph @ 39 psi
SEFI Mustang: 88 lph @ 39 psi
Ford Factory Fuel Injector Specifications
| Flow | Color | Factory Application | Injector Power Capacity |
|---|---|---|---|
| 14 lb/hr | Grey | Non Mustang 5.0 L V8's (trucks, not HO) | Don't bother. Change them |
| 19 lb/hr | Yellow | 5.0 L HO V8 Mustang | 330 HP |
| 24 lb/hr | Light blue | Cobra GT40 (93-95) | 400 HP |
| 30 lb/hr | Red | 2.3 L turbo (early models) | 500 HP |
| 35 lb/hr | Brown or dark blue | 2.3 L turbo SVO Mustang | 600 HP |
1979-1985 Foxbody Mustang V8 Ignition Timing
| Year | Initial Timing (deg BTC) | Centrifugal Advance (deg @ rpm) | Vaccuum Advance (deg @ in. Hg) |
|---|---|---|---|
| 1979-81 | 12 | 0.0 @ 1250rpm 8.0 @ 2150rpm 14.5 @ 5000rpm |
0.00 @ 3.5 14.0 @ 8.0 24.0 @ 13 |
| 1982 | 12 | 0.0 @ 1200rpm 10.0 @ 2000rpm 19.0 @ 5000rpm |
0.00 @ 3.5 14.0 @ 8.0 24.0 @ 13 |
| 1983 | 10 | 0.0 @ 1400rpm 9.0 @ 2000rpm 18.0 @ 5000rpm |
0.00 @ 4.5 11.0 @ 8.0 20.0 @ 12.5 |
| 1984 | 10 | 0.0 @ 1400rpm 11.0 @ 2200rpm 20.0 @ 5000rpm |
0.00 @ 4.5 10.5 @ 8.0 20.0 @ 12.5 |
| 1985 | 12 | 0.0 @ 1300rpm 11.0 @ 2200rpm 20.0 @ 5000rpm |
0.00 @ 4.5 11.5 @ 8.0 20.0 @ 12.5 |
1986-1993 Foxbody Mustang V8 Ignition Timing
Simply add the amount of your initial timing to any point along the curve and you'll have the total timing for that point.
For example if your running an A9L computer and 15 degrees initial timing and you want to know how much total timing you have at 2600 rpm.
You would simply add the 15 initial to the 22.5 shown on the chart for a total of 37.5 degrees.
| ECU | 1000 rpm | 1800 rpm | 2600 rpm | 3500 rpm | 5000+ rpm | |
|---|---|---|---|---|---|---|
| A9L | 8 ° | 18.5 ° | 22.5 ° | 22 ° | 26 ° | |
| A9P | 21.25 ° | 21.25 ° | 27.25 ° | 26 ° | 30.75 ° | |
| X3Z (Cobra) | 8 ° | 18.5 ° | 22.5 ° | 22 ° | 25 ° |