I am helping my brother with his 87 vette. The car will not run unless the throttle is constantly stabbed. I originally thought it was an ignition component,(plug wire possibly), however after a complete tune up no change. I have been burning tunes for him, and we looked to that next. We threw an old hypertech mem-cal in, and no change. I put the moates adapter back in with the flash chip, and accidentally put the mem-cal in backwards.The car runs fine, however it throws a code 41, (faulty or incorrect mem-cal).

So any ideas as to the problem?? Oh we did put another stock mem-cal in and the car runs terrible as well. Is the ECM bad? I remember reading something about limp home mode, is this why the car runs fine with the mem-cal in backwards?

Thanks in advance for your responses!
Craig

 

Just an update, we put his ECM in my car, and my car runs fine. Not exactly sure what is going on, but I think the key is that when the mem-cal was put in incorrectly the car runs fine.

Thanks

 

Ooops, I misread your last post.
So, let me get this straight...his ECM works fine in your car (pretty much eliminating the ECM as the culprit), what about the chips? Do the chips you're trying to use work in your car as well, but not in his? As far as the "memcal backwards" thing, when that happens I believe the engine runs off the base timing and computer control is completely disabled, which would explain why the car runs better.

Could be in the chip (I had a similar issue, and that's what was wrong with mine) or the ignition module.

 

Thats a good point, we did not replace the ignition module. We through two different Proms at it, and both didn't make any difference. Are cars are alot different, so I am not sure if his would even run on my tune, but I could try.

Would the ignition module just fail with no warning?

Thanks