3.2 conversion cars, Public service announcement Options

[mepstein]

We have 20 bad ecu's (3.2 engine computers) in the shop. I sent a couple to Steve Wong / 911 Chips for repair. He asked if they were from a 914-6 conversion car since they had a particular defective part. They weren't but most of our cars are 3.2's into early 911's so sort of the same idea. Steve said the reason we were blowing ecu's is because we were mixing the ecu's with a non 3.2 tach. It's very common for a 914 conversion to either modify their 4 tach with an electronic unit or modify an early tach to work with the 3.2. Steve said it may work for a short time, sometimes longer but failure often happens at high rpm. Go to the track, ralley or just some spirited driving and the higher rpm's kill the ecu's. I have to believe him since we have a pile of them to prove it. We had one burn out after 1.5 miles. Even hooking up the shift light wire on the 3.2 tach incorrectly will burn up the ecu's. Not right away but over time. A rebuilt ecu runs $900 and the burnt core is worthless. It's a known problem so it isn't accepted by most, if not all of the ecu rebuilders. You also must use a coil for a 3.2. No substitutes. All of this was unknown to me and the guys at my shop until today but you can be sure they will be more careful about this in the future. 1 more thing and it's something we did already know and practice, always remove the battery terminal from the battery when connecting your ecu.