M8 configuration for M PCHOP trigger wheel

[prsh]

M8 trigger config.jpg (7.48 KiB) Viewed 21104 times

Hello,

I have a very noisy rpm signal on a car fitted with this trigger wheel and want to verify the setup. With a timing light hooked up, I am seeing the timing jump around as much as ten degrees, and while tuning, the rpm is very "jumpy", this can be seen in the datalogs as well. There is a slight amount of slop between the wheel and the distributor shaft, which may be an issue, however I want to verify that the configuration is correct for this trigger wheel. Also, the wheel looks like the "M PCHOP CCW" , but I don't see any markings on it to verify. I see that there is a M PCHOP CW and M PCHOP CCW, one for clockwise and other other for counterclockwise rotation. Can someone identify which one I have ? Any help or suggestions appreciated, I would like to avoid having to put a separate cam and crank trigger on this car if I can.

[SprinterTRD]

Looks like a porsche distributor?
The distributor rotation must be the same as a Ford to use mode 182 have you tried mode 183?
It may be the detection of the narrow tooth that is giving you the problem

[prsh]

SprinterTRD, thank you for the help, yes this is a Porsche distributor. I have not tried mode 183, I see that modes 181-184 are all Ford Narrow Tooth, but don't see any other details noted. It was my thinking that there must me a setup sheet for this trigger that Motec sells for the this distributor. Hopefully someone from Motec will chime in.

[SprinterTRD]

The last number tells the software which edge is used as the running edge, which must be evenly spaced.
The short tooth's trailing edge is used for indexing the crank.
There are drawings on the MoTeC AU site that explains this.

You just need to work out what the running edge is, Rising edge ( the signal goes from 0V rising to 5V) or Falling edge ( the signal Falls from 5V to 0V).

Rising and falling edges are also explained in the online software help.

[Holmz]

You may want to check that the dizzy is ok too.
<Back in the day...> I saw the timing light showing hugh jumps when the dizzy bushing was worn out and that was points and condenser.
(I am assuming that the trigga-wheel is buried in the dizzy housing)