MS1 V3: Another RPM problem :( Please Help!

[churts]

Hi All.

I'm new to post here - although have been lurking around as a non-member for a while picking up information.

I have an MS1 V3.0 on my car and its runs perfectly...so I recommended it to a friend.

So, I am helping a friend who is converting his to MS and run into a problem.......

He bought a used MS1 V3.0 which was in running condition. It was being used to run a Mazda/Miata. He has a zetec engine and therefore needs the other RPM input circuit (VR). Unfortunately this hadn't been built onto the board, but from reading the manual it didn't seem to difficult. We ordered the correct parts from the manual and fitted them. Adjusted the VR pots back fully CCW and moved the jumpers as stated in the manual to select the VR circuit over the hall circuit.

It is still not reading any RPM on my stim (this is definitely working as I tested it on my own ECU). We are running 029y4 firmware on it if this makes any difference?

Other than trace and retrace the whole circuit looking for any visual problems, I'm out of ideas.

I'm really stuck at this point - so any advice is welcome!

Thanks in advance,

Matt

[Matt Cramer]

Can you make a tooth log of testing the RPM and post it along with your MSQ?

[DaveEFI]

Before going any further try adjusting R56 with the Stim connected. Usually, if it doesn't work straight off, about 6 turns clockwise can sort it. But of course may need adjusting for the real tach signal later. The VR input can change from not working at all to fine with a few turns of that pot. But it's not normally a critical adjustment.