Engine ECM/ECU

The Engine Control Module or Engine Control Unit is the computer that handles the engine management.  Most modern engines now use an ECU for controlling fuel delivery and many do a whole lot more too.  The Standard ECU on the Ford Modular engine also has PATS Passive Anti-theft System.  This is essentially an immobilisation circuit in the ECU that requires a special key with a transponder to be used to start the engine.

When you attempt to start the vehicle, the onboard computer sends out a RF signal that is picked up by the transponder in the key. The transponder then returns a unique RF signal to the vehicle's computer, giving it the ok for the vehicle to start and continue to run.

I had considered building a ECU based on the widely used MegaSquirt by Bowling and Grippo - a self build EFI system that a number of aftermarket companies are now building and selling as a solution to almost any EFI based system.  However, when I looked into it in a bit of detail it didn't look like it could be used as a sequential controller for the injectors of a V8.  (I believe that the latest version as of a few months ago now will support Sequential firing of 8 Cylinders).  I also got little to no assistance from the main UK supplier of the MegaSquirt simply an email stating that he was busy right now and to try someone else (Very Helpful).

So I decided to give that a miss and look at what else was available.  There are a number of aftermarket ECU's out there and I ended up with the following options:

  1. 1. Cheap System, with little to no specific details for individual applications

  2. 2. Fairly flexible systems that are reasonably priced but not able to handle sequential 8 cylinder

  3. 3. Very Expensive professional systems able to handle sequential 8 cylinder, usually used in race applications.

  4. 4. Use the original Ford ECM and Wiring Harness

  5. 5. Use the Original Ford ECM, but have it modified and use an aftermarket wiring Harness

After quite a bit of deliberation I decided I didn't want to build the truck as a 600HP racer so I didn't need to have a real expensive professional setup.  I also didn't want to go with a real cheap system and find I had lots of problems with it and had to spend hours and hours trying to work out the wiring.  One of my main concerns was actually wiring all of the engine sensors etc up.  I had half of the original engine wiring harness but not the part that connected to the original ECM, so I would have to work out exactly what went where and how to connect everything up unless I could find the extra bit of harness I was missing.  I tried finding the extra harness, but eventually gave up after learning that the standard Ford ECM contained the anti theft programming that would prevent the engine from running unless over rode.

After a little research I found that there was a company (The Detail Zone) who provided a complete engine harness that would hook up to the original Ford ECM, but the same company would also reprogram the ECM to remove the Anti-theft option and also tweak it in a few other areas too.   So in addition to getting the new harness I also had the ECM re-programmed to remove the anti-theft components and have it set up for an aftermarket Fuel pump.  The standard Ford Fuel pumps used on the Modular engine are in tank variable voltage units that increase or reduce the pressure as needed and has no fuel return.  I will be using an aftermarket pump, so need constant Voltage and I will have a return back to the tank.