lost tach signal

[mudbasher]

s14 sr20det ms2 3.0 pcb diy auto tune 12-1 cas wheel. had engine running yesterday then lost tach signal. checked wiring earth & 12v at cas sensor good. checked continuity on signal wire from cas to ecu 0.9ohms. signal alternates 0 to 5v as i rotate engine. i've been playing with ing settings to get seq ing working but can't see what would cause loss of signal. tried it on jim stim and ecu gets tach signal. any ideas?

[Matt Cramer]

Can you also post a tooth log from the Diagnostic menu?

[mudbasher]

came out to garage today. cranked with no tach signal then signal came and engine ran. then signal appared to come and go. managed to get a few logs. was wondering if i need to redo r50 r51 for the cas signal filtering? i had it all set before i rebuild motor but didn't change cas sensor.

[mudbasher]

R52 & r56 sorry not r50 & r51

[Matt Cramer]

It looks as if it's having a hard time syncing at low RPM. Adjusting the physical CAS angle can sometimes put the missing tooth in a spot that's easier to pick up.

[mudbasher]

Ok. Ill try rotate the cas and re time it.cheers matt

[mudbasher]

pulled CAS out and spun it by hand, Matt was right it was struggling to sync at low rpm. shifted the timing offset from 120 to 360deg and when spun it by hand and it now sync's well. put CAS back in re-timed the motor with 47deg timing offset & it now sync's and starts . cheers Matt