Ms1 V2.2 trigger fault

[cncautomotive]

Right so I have a vehicle in my workshop at the moment , Ford Transit with a lexus 1uzfe vvt motor swapped into it. The ecu has a VR condition circuit built in using the conventional LM1815 circuit, I didnt build the ecu but it looks correct. The issue I am having is the engine will free rev to around 3500 rpm and start to miss fire but when it is on the dyno under load it will start missfiring as soon as it is above about 65% throtle at any rpm. The problem starts at around 1200 and is there everywhere, so far I have tried resistors inline with the VR+ wire with no change except if I put over about 8k ohm it loses rpm input. I got my scope out and started checking for noise etc and it all seems fine, I have scoped all the way to the LM1815 chip and the signal going in is fine but the output to the ms1 cpu has missing teeth at random. I will like to a vid of what is happening .
https://www.dropbox.com/s/k5zjtjyhg7pia ... 4.avi?dl=0

[cncautomotive]

I have also replaced the LM1815 chip with another new one I had here in stock with no change.

[slow_hemi6]

What are the values of the resistor and capacitor connected to pin 14? f it is 39K and 0.01uF the one shot output might be falling over around 3Krpm with a 36-1 trigger. Data sheet suggests you can get 5Khz from 150K and 0.001uF that would be over 8Krpm with 36-1 but I don't know if there would be any detriment at low rpm or not.
Actually looking back to 2008 it seems the Jean suggests just grounding the pin14 and removing the RC.

[racingmini_mtl]

Actually looking back to 2008 it seems the Jean suggests just grounding the pin14 and removing the RC.

It is indeed the best thing to do.

Jean