Ever since converting to manual I was always sure my car had lost low end torque. I had gutted the cats at the same time and thought that was the cause. New (and better) cats didnt solve the problem so it somewhat left me stumped... untill tonite.
I had always beleived that the EA - EB1 auto's and up to ED V8's (unsure about EF and EL but I suspect it would be the same) were able to use the original Auto version of the engine ECU when converted to manual.
This is true for the 6cyl but not the V8's.
Basically the V8 have an operating mode where in reverse gear they run a torque limiting mode to protect the reverse gear. There is a link from the auto trans ecu to the engine ecu dedicated for this mode.
The problem when changing to manual and there fore removing the auto trans ecu is that the engine ecu no longer receives the signal. This poses a problem. Here is a peice copied directly from the Ford Factory Workshop Manual: Section 7-2-70
Default Engine Operating Modes
7B:Reverse Gear Indication
Engine Controller, EEC-IV will assume torque cut off mode in all gears. However when the calculated engine-to-road speed ratio is outside the range of the reverse gear, toque cut off is ignored. If a fault is undetected, a reduction in power may be percived in lower forward gears and shifts may be firm
So obviously the firm shifts won't apply to the manual but the lack of power will. It will be evident throughout first gear and at the start of 2nd I think. This is the exact reason why I have felt my 2nd gear was quicker than 1st to accelerate. It also explains why it doesnt show up that well on the dyno. Basically when its in 3rd gear its only at really low RPM that it will be in the torque limiting mode. There is no EEC fault code for the missing signal
The connection is between pin 3 on the 95LE trans ECU and goes to pin 5 on the engine ECU. Looking at the chart with the different states of the various outputs and inputs the Transmission Communication Link gives the EEC a 25hz or 50hz signal depending on the state (reverse or not). So that makes things harder because it isn't as simple as using a resistor and feeding pin 5 with the correct voltage.
A friend of mine who is pretty clued up with Falcon's has a couple of EB1 V8 ECU's and we are going to retrofit one into my car. We will have to wire in a BAP sensor and also rewire the WAC relay for the air conditioning. This will also mean I will lose the recirculation override feature of the air con system.