97 ECM work?

[JohnnyC]

Hi new member I have an 02 Ranger A/T with an 01 Mountaineer 5.0 I was told to use a 97 Explorer V8 ECM to eliminate Pats. Ive been reading up on it and it seems I may have an issue with the transmission shifting with the 97 ECM. Is this true?

 

[JohnnyC]

Anybody? Bueller? Bueller?

 

[RonD]

The issue would be with the speedometer not transmission(4R70W)
AND fuel system

The explorer/mountaineer used the 4 wheel ABS module for speedometer and computer speed signal
Rangers never did, and in 2002, Rangers used a new sensor on transmission for speed signal, OSS, which you no longer have but wouldn't matter since 1997 PCM(ECM) couldn't use it in any case

So you will need to use a speedometer interface to make this build work, seen here: https://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=1192/mode=prod/prd1192.htm

You will tap into the rear ABS sensor's 2 wires for the speed source(INPUT) then run a wire from OUT 3 to computer, speedometer and Cruise(if so equipped)
These may already be hooked together with a grey/black stripe wire, so you just need to splice into that 1 wire to feed all 3 the speed signal

Fuel system
1997 V8 PCM was most likely programmed for 30-40psi fuel pressure
2001 V8 fuel system(and 2002 Ranger) would use 55-65psi fuel system
It should still start and run but VERY Rich until it warms up, then PCM can cut back injector open times, and it should run better, but will set Rich codes

Starting in 1998 Rangers the fuel system was changed over to Returnless, one fuel line to the engine bay
2001 V8 should also be Returnless
Returnless ran 55-65psi fuel pressure

1997, and earlier was 30-40psi
There was never a fuel pressure sensor on Ranger or explorer/mountaineer
Expected pressure was just programmed in to the PCM's air/fuel mix tables as were injector size for that year
So computer(PCM) knew EXACTLY how much gasoline would flow out of each injector if it was opened for say 100milliseconds
If fuel pressure is bumped up by 15/20psi, that's a 40% to 50% increase, so 45% more fuel is flowing in than PCM expects, making for a Rich mix

You might be able to run smaller injectors, not sure on how to calculate that

You could run an external FPR(fuel pressure regulator) to set the 35psi, but still may have to change injectors if 1997 V8 ran different size that 2001
Injectors are rated in Pound Per Hour, like 14lb/hr is 14 pounds per hour of gasoline flow at 40psi pressure, 39-43psi is used for fuel injector ratings

Your current setup has the Fuel Pump and FPR inside the gas tank
The fuel filter has 3 hoses
One come from the fuel pump
One goes out to the engine
The 3rd goes back to the gas tank and the FPR inside the tank, FPR is rated for 60psi, not sure you can adjust it for 40psi

You may be better off to send out the 2001 Mountaineer PCM to have PATS deleted, vs running the 1997 PCM with current setup

But regardless you will need the speed interface device, almost all V8 Ranger swaps need that, except 1998-2000 Rangers, lol, they have a build-in interface, GEM module in those years did that

 

[JohnnyC]

Wow! Thank you Ron D for all that info. So I guess from what your telling me I should scrap the 97 ECM. I think I will get the pats removed from my 01 Mountaineer ECM and use that as you suggested. I will still need the Dakota Digital speed interface which I will order ASAP. I believe I still need the wire grounded in the Ranger harness going to the engine harness. Thanks again for your help

 

[RonD]

You will need to ground the Starter Relay in the engine fuse box, if PATS is by-passed, PATS grounds that relay via the PCM pin 44, allowing starter motor to work

Starter Relay has a Dark Blue/orange stripe wire that runs to pin 44 of original PCM and should be same pin 44 on the 2001 PCM harness
Just needs to be grounded


Pin 58 on the 2001(or 1997) V8 PCM is the Speed IN, grey/black wire
Pin 1 connector "B" on back of cluster is Speed IN, same grey/black wire
Pin 3 on Cruise control module is Speed IN, and .......................yes, same grey/black wire
These 3 share the Speed signal on that 1 grey/black wire

Rear axle ABS sensor has two wires, the sensor generates its own AC Voltage when axle is spinning
0.5vAC to about 7vAC at 75mph
But the voltage in not used, the AC sine wave up and down is used, the frequency of the up and down pulses is what is used
Rear axle sensor generates "about" 20,000PPM(pulses per mile)
Ford uses 8,000PPM AC for speedometer, computer and cruise calibration
The "about" is why you need the interface, and will need to calibrate it for PPM