no tach signal gm 8 pin
Posted: Tue May 29, 2012 11:50 am
ok... MS2 v3.0 board NOW RUNNING v2.905
I used this ECU with v2.885 to control fuel only on a ford straight 6. it often had a noisy tach signal so i used a diode inline to quiet it down which worked. i have since pulled the ford straight 6 and dropped in a chevy v6 turbo charged with TBI injectors. the new motor uses an 8 pin small cap external coil distributor which i plan to use timing control to pull timing as boost comes in. i have tried every mod including the MK-HEI mod kit from DIY. i used the DIY nova project as my blueprint. that got me nothing in the way of a tach signal. so after searcing for a bit i stumbled onto the MSextra wiring that uses the d14 and d16. i wired that up and i got the motor to fire but ran very very rough. lots of bad starter kick backs even with the base timing set at 10deg (verified with timing light). i currently have my whole timing map set at 14 degrees. it seemed like the timing was erratic. i was looking on the laptop at some of my settings...i had the key "ON" but the motor wasnt running. i heard my fuel pump kick on..and off and on then noticed my injectors firing intermittently. i then realized that i was still running the v2.885 firmware. so i installed the MSextra 3.2.1 firmware thinking that will fix all my problems. since i have upgraded to the MS extra i cant get a tach signal at all. i tried the tooth logger in tuner studios and didnt register anything. with the 4 pin connector disconnected from the distributor i get spark.
UPDATED>>> i have since went back to the V2.905 with the MSnS-E modification and still absolutely no tach. would it be worth my while to replace the optoisolator at U3? i feel i have tried every mod out there to no avail
any help would be greatly appreciated!
Vic
I used this ECU with v2.885 to control fuel only on a ford straight 6. it often had a noisy tach signal so i used a diode inline to quiet it down which worked. i have since pulled the ford straight 6 and dropped in a chevy v6 turbo charged with TBI injectors. the new motor uses an 8 pin small cap external coil distributor which i plan to use timing control to pull timing as boost comes in. i have tried every mod including the MK-HEI mod kit from DIY. i used the DIY nova project as my blueprint. that got me nothing in the way of a tach signal. so after searcing for a bit i stumbled onto the MSextra wiring that uses the d14 and d16. i wired that up and i got the motor to fire but ran very very rough. lots of bad starter kick backs even with the base timing set at 10deg (verified with timing light). i currently have my whole timing map set at 14 degrees. it seemed like the timing was erratic. i was looking on the laptop at some of my settings...i had the key "ON" but the motor wasnt running. i heard my fuel pump kick on..and off and on then noticed my injectors firing intermittently. i then realized that i was still running the v2.885 firmware. so i installed the MSextra 3.2.1 firmware thinking that will fix all my problems. since i have upgraded to the MS extra i cant get a tach signal at all. i tried the tooth logger in tuner studios and didnt register anything. with the 4 pin connector disconnected from the distributor i get spark.
UPDATED>>> i have since went back to the V2.905 with the MSnS-E modification and still absolutely no tach. would it be worth my while to replace the optoisolator at U3? i feel i have tried every mod out there to no avail
any help would be greatly appreciated!
Vic