Ok, I got a full standalone EMS (australian made) running my B16a/B20bVTEC for over a year now (daily driven). 3 weeks ago, my battery went dead, replaced the battery only to find out that I had a bad alternator, I can't find a b16a alternator so alternatively I bought a b20b alternator which has roughly the same dimension apart from having a slightly bigger pulley and different terminal for its Ig, L and etc. Quick fix was to just jumped the wire and i ensured i got the right wire to each terminal. Car ran well with no problem.

2 days later, I can't seem to start my car after having lunch only to find out that all my ECU mappings were gone!!! What gives? I pulled out the battery to reset everything back and mappings were back in order. Next day, drove for 2 hours, the whole car started to jerk and eventually the car died while driving. I pulled over and checked that the whole mappings were gone again. I had to retune the car again and after 2 hours, the car ran fine again and guess what.... it lost its map AGAIN!!!!

What can cause the ECU to lose its mapping? I doubt its the alternator though coz i know a lot of guys who's running it as well without problems. I'm scared to even drive my car now because it only loses its mapping when the car is driven, its basically sitting in the garage at the moment until i get idea's on what can cause this to happen. I haven't taken the ECU apart yet to check whether i got some fried diodes etc... Even if it did, i still can start the car and let it run standstill without problems, so thats ruled out already. Can improper groundings be a caused??

Any input is greatly appreciated.

 

oh yeah, sorry for the bad grammar.

 

*bump*