KdPate
After Hours Garage
I've been contemplating this for a good while now but have decided to do it: I'm converting the truck to mass air. To give you a little background on the 87-91 trucks, Ford set the computer up to be a Speed Density bank fire setup i.e. it fires 4 injectors at once instead of one at a time (bad for fuel mileage and emmisions; might as well kept a carb on there). Plus upgrading to a better exhaust, camshaft, heads, etc. leave little to no margin for the computer to upgrade. Now I'm changing that. On with the goods (used of course):
The mass air meter and computer. Both are from a 1993 Mustang Cobra
The wiring harness from the same car. Going to have to modify it in order to intergrate it into the exisitng truck wiring harness.
After removing the sheathing and pinning out the connectors I was able to seperate the injector harness for the rest of the main harness. Themain part I actually needed was the injector harness since most of the sensors are the same between the vehicles; just in different locations.
In the end I was able to get the main harnesses I needed. The injector harness and the MAF harness...
I also managed to complete the "overlay" harness as well and pick up this gem at Pull a Part for $17....
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Installation was pretty much "plug-and-play" to say the least. Disconnect the existing injector plugs, overlay the injector/MAF harness, etc. The real PITA was when it come time to re-pin the 60 pin connector. Removed 3 pins entirely, remove, re-locate 4 pins, add the injector harness/ MAF sensor pins. Done. I ran a jumper for the HEGO sensors combining the left and right (IIRC the Ford Racing kit did the same thing) and used the MAF I found @ Pull-a-Part. So far I have only one code for a canister purge selenoid whic my truck doesn't have.
Here is what I've learned doing this:
1) the fabled X3Z (1993 Cobra computer) WILL WORK. Even with the 19lb injectors and the 1994-1995 V6 Mustang MAF it runs very good. No lean-out whatsoever.
2) The firing order and the injector pinout need to correspond with each other. It idled like **** initially until I matched the injector and firing order. Non-HO firing order 1-5-4-2-6-3-7-8. HO/351W firing order 1-3-7-2-6-5-4-8. Only have to swap around the pins forinjectors 3, 4, 5, and 7 to get it right. Runs very smooth.
3) 87 octane + 15 degrees of timing + MAF conversion = SPARK KNOCK FROM HELL!!!!!! Bumped the timing down to 11 degrees and all is well.
That is all........for now.......

The mass air meter and computer. Both are from a 1993 Mustang Cobra


The wiring harness from the same car. Going to have to modify it in order to intergrate it into the exisitng truck wiring harness.

After removing the sheathing and pinning out the connectors I was able to seperate the injector harness for the rest of the main harness. Themain part I actually needed was the injector harness since most of the sensors are the same between the vehicles; just in different locations.


In the end I was able to get the main harnesses I needed. The injector harness and the MAF harness...


I also managed to complete the "overlay" harness as well and pick up this gem at Pull a Part for $17....


Installation was pretty much "plug-and-play" to say the least. Disconnect the existing injector plugs, overlay the injector/MAF harness, etc. The real PITA was when it come time to re-pin the 60 pin connector. Removed 3 pins entirely, remove, re-locate 4 pins, add the injector harness/ MAF sensor pins. Done. I ran a jumper for the HEGO sensors combining the left and right (IIRC the Ford Racing kit did the same thing) and used the MAF I found @ Pull-a-Part. So far I have only one code for a canister purge selenoid whic my truck doesn't have.
Here is what I've learned doing this:
1) the fabled X3Z (1993 Cobra computer) WILL WORK. Even with the 19lb injectors and the 1994-1995 V6 Mustang MAF it runs very good. No lean-out whatsoever.
2) The firing order and the injector pinout need to correspond with each other. It idled like **** initially until I matched the injector and firing order. Non-HO firing order 1-5-4-2-6-3-7-8. HO/351W firing order 1-3-7-2-6-5-4-8. Only have to swap around the pins forinjectors 3, 4, 5, and 7 to get it right. Runs very smooth.
3) 87 octane + 15 degrees of timing + MAF conversion = SPARK KNOCK FROM HELL!!!!!! Bumped the timing down to 11 degrees and all is well.
That is all........for now.......


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