As the begining of this topic shows, I suffered numerous FET failures without any real reason, and no one can to this day tell me what the cause was other than the box being a self build. With the advice of one of the developers, I installed the IGTBs and been running since
I did everything recommended to replace blown FET devices, I changed all the FET driver chips, 4 in total, the FET gate resistors and the FET driver capacitors. The loom was completely pulled apart to check for faults. The loom was ALL new wire and built as per the guide lines, injectors were changed, grounds were remade closer to the ECU, and it made not one blind bit of difference.
IGTBs would appear to be a quick solution where there appears to be no answer to the FET failures and when all other avenues have been exhausted. You
MUST use
ALL IGTBs for
ALL injectors on the same engine. I would expect that if IGTBs start to fail in this situation that not all probable faults have been eradicated.
I have just replaced the last of the FETs in the box with IGTBs (excluding WBO2). I am now only 4 short on the ignition chanels for a full house
Looking back, I can see possible where the prime mover for these failures came from, but I am not clever enough to actualy understand it if it was. I used what I thought was a bipolar stepper motor, when infact it was a DC motor and a switch (four wires) I did not check the reistance. This smoked one of the stepper chip drivers. this was at first start at the time i suffered the first failures. While mucking arround, I split the grounds as strongly suggested NOT to do and then smoked the P259 chip, at which time I think it damaged the Mcp ADC chip, which showed up as EGT chip failures or at least I thought.
My black box has had a hard time of it, but its still going and I have become quite good at replacing surface mount chips with only the basic tools
And I dont think its going to be the last I do
