Dan D
Well-known member
Is the tachometer driven directly off the CAS, Ignition transistor, or a dedicated ECU output?
My car has a bizare misfire/rev jump around 3K rpm at low to mid throttle (> 5 psi boost). It doesn't show up on a log, but you can see the tach skip. There is a slight hesitation around that point and sometimes knock(but not always).
I've tried a couple different timing curves around that area of the map to see if I can affect it, but it makes no difference. Plug wires are new but the CAS, Transistor, and coil pack are all original. I wish I had spares laying around to swap in and out, but I don't.
I'm kind of stumped because I can't get it to show on a datalog so I can't correlate any other parameters to the condition. I've tried to monitor the logger visually to see if I can notice a timing or tps snafu, but all looks good.
Ideas?
My car has a bizare misfire/rev jump around 3K rpm at low to mid throttle (> 5 psi boost). It doesn't show up on a log, but you can see the tach skip. There is a slight hesitation around that point and sometimes knock(but not always).
I've tried a couple different timing curves around that area of the map to see if I can affect it, but it makes no difference. Plug wires are new but the CAS, Transistor, and coil pack are all original. I wish I had spares laying around to swap in and out, but I don't.
I'm kind of stumped because I can't get it to show on a datalog so I can't correlate any other parameters to the condition. I've tried to monitor the logger visually to see if I can notice a timing or tps snafu, but all looks good.
Ideas?
