How the 4A-GE ECU works

[SuperHessu]

Hmm... I have an ECU for my AE86 which is made for Group-N rallycars, and I could'nt pass the emissions test's with it so I started to examine. I used an 80's Toyota tester called the TCCS-checker which basicly is connected between the ECU and wiring harness and allows you to display all the sensors signals. Well all the sensors were ok, but I notest a very okward thing, I could disconnect the TPS-signal from the ECU and it had no affect on the engine at all I opened the ECU and there were a few things changed:

1. I don't know what theyre colled in english but they're the things that have resistance, I thould they're changed to alter the signals to "fool" the ECU to run the engine "wrong" as in richer.

2. There were a few black boxes changed, the kinda that have lots of "feet" around them connected to the board. [ LOL at my english vocabulary ]

3. There was a wire on the board connecting two dots that werent originally connected.

Questions:

1. If the stock ECU doesn't use the TPS signal nearly at all as you said, could it be that the Group-N ECU has been modified to ignore it totally??

2. Could that extra wire be there to get an other map running??

To np303: As I have the engine in TE-71 I had to make some of the wiring myself and the stock AE86 ECU has a diagnostic ability similar to newer Toyota ECU's. Meaning it displays trouble codes by flashing a LED.

If you want I can take pics of the ECU board this weekend, I bought a stock ECU for my AE86 so it's free for examination. Oh and by the way, have you ever gotten familiar with the Saab ignition system?? I'm working as a Saab/Mercedes/Honda/BMW/Citroen mechanic so I have. I'm planning to use a Saab-ignition cassette on my 4A-GE, which basicly allows you to sensor the firing quality inside the engine It'll be sometime next year that I'll have time for this thou..