Spikes in RPM signal (coil negative terminal)

[voytas]

I have problems with RPM signal taken from coil's negative terminal.
It is correct but very noisy - there are some spikes in the graph (RPM value sometimes jumps from 600 to 3000).

I am using v2.2 board without Dave's capacitor, default R10 and C12 values and D8 (John) diode jumpered.

I've read that there are several fixes I could try:
- add a Dave 220pF capacitor
- increase R10 value
- remove jumper around D8

From which one should I start?

Spikes can be observed in attached log.
Thanks for any suggestions

EDIT:
MS-1 PCB v2.2 - B&G 3.0 code

[Matt Cramer]

Add the Dave cap and un-jumper D8.

[voytas]

Add the Dave cap and un-jumper D8.

I've added Dave cap (which is 220nF and not 220pF as I've written before) and spikes are gone.
D8 is still jumpered.

Thanks for help Now I can start removing stock K-Jetronic injection...