instabillity in tach input

[water1982]

HI everyone ,

i'm working on 2 car but with the same motor , 3S-GTE.the 2 motor using the same trigger wheel ( 12 theets with a second trigger). the 2 car idle fine but at neer 2.5k rpm , i'got some glith in RPM and the timing is lost sometime.

there is the difference betewen the 2 car

fisrt car > V2.2 with 2 circuit lm1815

second > v3 with one circuit lm1815

all the board was test with a WAV file with teh sound of 12 theets with second trigger at 8k rpm and everyting runing fine but, in the car .... you know.

-thank