MSefi.com read only forum (Jan.15,2018)

Hi guys,

I've got a problem with my ms2 v3 hei 7 pin tach signal. I buildt the ms2 using the hei description on de ms site and added the 100ohm resistor and jumper update as described on DIYAutoTune.

The problem is as follows if i'm cranking he rpm signal is perfect in the logs but when the engine catches rpm jumps to about 600 and right after that it drops to zero and to the cranking rpm again. Also the tach count resets to zero. This repeats every time the engine catches(tries to start).

To me this looks like the rpm signal isnt strong enough to follow a rapid change of engine rpm.

What could this be?

Thanks a lot,

Edd

here is a log where it started died right away, I cranked again started and died right away

I think we would be interested in seeing your msq also...........

Ken

Your right i havent got my current log on this computer but here s the one i used to base mine on. Only the fidle in this one is different. I use fidle to control the vref for the ignition timing

I had a similar problem starting mine. I have an 8 pin HEI. The problem was the wires on the output of the "Limp" relay had gotten reversed. It was an easy fix, but hard to diagnose. Nothing made sense.

In the relaxed mode, before starting and running, I accidentally connected the output to 87A instead of 87. It gave really weird cranking datalogs. If I remember correctly it would try to run BADLY every two seconds during continuous cranking.

Hope this helps.

Holl