RB20DET tachometer problem

[Benz_200t]

Hi guys....i have an old W123 benz with a RB20DET in the engine bay.....

recently i just had done some wiring to the car.....and accidentally snapped the tachometer wire signal to the meter.

after i connect it back, the tach goes weird...

when the engine is not running, the tach will be at 0

if the engine is running, the tach is pointing to 3000rpm....

i have traced the wire directly to the ecu pin no7...thats the rpm signal pin..

for your information, i am using a A31 meter.

i dont know what is the problem...

found some info in SAU and SDU websites....and i have not found any cure for my problem....

i am very stressed with this problem...it has been a month now trying to settle this problem on my own.....

i really hope that u guys could help me.

of at least do teach me on how does the ignition signal worked on the RB20DET engine thus giving signal to the tach.

Maybe from there i have some ideas on how to solve this problem.

thanks alot in advance......

[fast_s13]

make sure you dont have a short in the wire

[Benz_200t]

i have checked for any type of shortage.....

even,i have done a new wiring for the rpm meter....