Electrical Use a 94 engine with 89 GT wiring and A9L ECU in non-Ford chassis?

[Wallyman]

Trying to use an all original 1994 complete pullout for an engine swap into a non-Ford chassis. Pullout was bought without engine harness or brain, and I separately bought an 89 GT engine+injector harness and matching A9L brain (based on this being the defacto solution to run a 94-95 for years).. but I am coming up completely dry on the 'how" of doing it. Here's what may influence the potential correct answer:

Converting to Carb is not a preferred option (even tho I know that would solve all my questions)
I want/need to keep SN95 accessories and front dress for space packaging reasons. Converting to Fox body parts is not a preferred option (due to cost and impact on space - fans have to become pushers at minimum).
I want/need to keep SN95 intake for space packaging reasons. Converting to Fox body parts is not a preferred option (due to cost and impact on space - will mean cutting of hood structure at minimum).
I am using a foxbody T5 and bellhousing
Will not be using AC, may not be using PS (car was setup for manual but PS would be nice and I have access to a power rack so it's being considered)
Doing electric fans for cooling, with external stand alone controller
No Mustang dash and other harnesses in play
Cruise control will be chassis-based, not the Mustang system
Temp gauge sender will be converted to match chassis
Oil pressure gauge sender will be converted to match chassis

So, Is this possible? And what specifically will I need to address? I've found very few crumbs after hours of searches.. some mentioning of extending wiring to some sensors is possible.. maybe a rewire of the TPS? Again, nothing very concrete or clear....so any help appreciated!

 

[Noobz347]

Unless you are, for some reason, completely enamored with that A9L and harness, I would totally look into a Terminator X or something you can just wire into the sensors and go.

Can the A9L be done? Oh yeah, given the man hours.

 

[Wallyman]

Unless you are, for some reason, completely enamored with that A9L and harness, I would totally look into a Terminator X or something you can just wire into the sensors and go.

Can the A9L be done? Oh yeah, given the man hours.

Let's just say I am totally enamored and I have the man hours... this is a budget (cheap as possible) build and wiring doesn't scare me. A $1500 terminator is outside the budget.

Sensors are the question, specifically any differences between the two years and how to address them. I've been collecting what I can find online for reference but haven't found a conversion list.

 

[General karthief]

I would find a fox computer harness, 1989 started the 50 state mass air stuff, before that only California models had mass air, 90 up had additional wires for air bags but you don't have to use those wires for anything, speed density can be converted to mass air.
A good wiring diagram and time/patience, any sensor wires can be extended/adjusted as needed.
The accessory drive has no bearing on harness for computer.
Worked on a old Ford Fairlane that used the 89 computer and harness, it is important to use the computer grounds in the harness.
Best I can do.

 

[AeroCoupe]

Being you have an A9L and an ‘89 ECU harness and matching injector harness you are 2/3 the way there. You need the O2 sensor harness and it need to be pinned for a manual transmission. Search this as it’s been discussed on here many times.

If you have the distributor from the 94/95 motor then the TFI was remotely mounted which will not work with any of the 87-93 ECU harnesses so you will need a Fox specific distributor.

The ACT sensor was also relocated into the air inlet tubing on the 94/95 cars and it’s in the #5 lower intake runner on the Fox cars. I believe you can just lengthen the wires to on the 89 harness to utilize the relocated sensor but not 100% on that. I only hesitate here as the temps will be cooler this it will want to add more fuel. This may or may not need tuning to optimize.

Throttle body TPS wiring will need to be lengthened.

I’m sure there will be other small things but that is all I can think of off the top of my head.

 

[Wallyman]

Being you have an A9L and an ‘89 ECU harness and matching injector harness you are 2/3 the way there. You need the O2 sensor harness and it need to be pinned for a manual transmission. Search this as it’s been discussed on here many times.

If you have the distributor from the 94/95 motor then the TFI was remotely mounted which will not work with any of the 87-93 ECU harnesses so you will need a Fox specific distributor.

The ACT sensor was also relocated into the air inlet tubing on the 94/95 cars and it’s in the #5 lower intake runner on the Fox cars. I believe you can just lengthen the wires to on the 89 harness to utilize the relocated sensor but not 100% on that. I only hesitate here as the temps will be cooler this it will want to add more fuel. This may or may not need tuning to optimize.

Throttle body TPS wiring will need to be lengthened.

I’m sure there will be other small things but that is all I can think of off the top of my head.

O2 harness - I have seen that.. must match tranny or bad things happen to the brain. Not sure if my purchased harness has it, will check when it arrives. This spells it out pretty well (and looks like you can convert an auto to a manual if need be): https://www.allfordmustangs.com/thr...3537&nested_view=1&sortby=oldest#post-8863537

Motor has the 94 Distributor.. Searches show moving the TFI remote is a common 'update' for a lot of Fords (https://www.therangerstation.com/tech/remote-mounted-tfi-ignition-module/), you just need the right wires/shielding.. but even better McCully has a harness that will do exactly what I need, I am just lacking the TFI module but I should be able to find one of those. (https://www.mccullyracingmotors.com/index_files/Page1704.htm)

ACT, looks like it's a super common question asked on tapping Explorer and GT40 intakes.. 9/16" drill bit and 3/8" NPT tap. Looks like maybe the 94-95 has the same undrilled boss area, I'll check into it. Understood on inlet vs intake temp variance and the corresponding programming impact.

So lengthening TPS wires solves it, and no reason I would be forced to convert to Fox TB/TPS... right?

Tell the top of your head I appreciate it! If you think of anything else, let me know.. that's super helpful.

 

[AeroCoupe]

I have the McCully Racing relocation kit on my Coupe and it works great!

 

[Wallyman]

Couple updates/plan..

Got a factory 89 EVTM wiring diagram (finally!)
Got the full 89 harness (main, injector and O2) with A9L.
Coolant temp sensor wires are short, need to extend
TPS has to have the plug swapped to the 94 plug
EGR stuff gets taped back (smog and EGR removed)
EGR ports on back of head blanked using $2 worth of bolts from Lowes
EGR port on intake getting blocked using 351 fuel pump block off plate
Low oil level wire taped back (not used in Monster Miata swap pan)
Intake air temp wires reach stock location, which on a 94 intake has to be drilled (3/8" NPT)
Miata OEM temp sender goes in Fox location (with thread adapter) in the thermostat housing, that's also drill and tapped. Wiring independent of the Fox (wire to Miata factory gauge)
Oil pressure sender (using a VDO unit that works with the 95 dummy gauge, based off the NB dummy gauge conversion kit at Moss Motors) gets remote located, NPT to AN line, that also routes to Miata dash independent of Mustang harness
TFI, using the McCully racing relocation kit for the SN95.. so basically replicates the SN95 configuration, using SN95 distributor. TFI will be remote mounted with heat sink, hooks into SN95 distributor pigtail and Fox harness.
MSD 6AL gets wired in like they normally do
Starter wiring uses body/Miata wires, remote mount solenoid is gone (using SN95 starter)
Low pressure adjustable FPR goes away, running stock Miata fuel pump for EFI motor
Running alternator only (no PS, AC or Air pump). Cut the Alt bracket off below mounting points
Swapping the idler to a grooved unit. Going to try Gates 36230 which has same inner bore, mounted using either hacked down stock mount or maybe an aftermarket idler only if I can can't make it work.
So accessory belt will run Crank, Alt, Idler, water pump with factory tensioner.

I think that is it for now...

 

[AeroCoupe]

Only question I have is with regards “Low pressure adjustable FPR goes away, running stock Miata fuel pump for EFI motor”.

You do know that the Fird WCU is expecting 39 pig at the injectors and a stock Miata fuel pump delivers more than that.

 

[Wallyman]

Only question I have is with regards “Low pressure adjustable FPR goes away, running stock Miata fuel pump for EFI motor”.

You do know that the Fird WCU is expecting 39 pig at the injectors and a stock Miata fuel pump delivers more than that.

Perhaps, but it's not something that's even mentioned in the Monster swap manual (just re-read all the fuel related instructions) so I'm going to go with "close enough for my box" The FPR I have in the car was for a carb'd engine, so 6psi wasn't going to help me anyhow Worst case, I am over driving the injectors and running rich.. and I can add a FPR later. But shouldn't the A9L (with it's O2's) adjust fuel trim if it is seeing richness?

I'll toss it to the V8 guys on FB and see what they think (including Martin who wrote the book, literally). Thanks for the tip!

 

[Wallyman]

Perhaps, but it's not something that's even mentioned in the Monster swap manual (just re-read all the fuel related instructions) so I'm going to go with "close enough for my box" The FPR I have in the car was for a carb'd engine, so 6psi wasn't going to help me anyhow Worst case, I am over driving the injectors and running rich.. and I can add a FPR later. But shouldn't the A9L (with it's O2's) adjust fuel trim if it is seeing richness?

I'll toss it to the V8 guys on FB and see what they think (including Martin who wrote the book, literally). Thanks for the tip!

Only question I have is with regards “Low pressure adjustable FPR goes away, running stock Miata fuel pump for EFI motor”.

You do know that the Fird WCU is expecting 39 pig at the injectors and a stock Miata fuel pump delivers more than that.

wasn't thinking when I replied.. I'm using the factory SN95 FPR, so why would I have issues? It's a return style system (95 Miata chassis)

 

[AeroCoupe]

You said you were deleting the low pressure fuel regulator so I assumed you were referring to the stock mustang FPR being it is set at a lower pressure that what a stock Miata uses. Now that you have pointed out you removed a low pressure carb regulator it makes sense.