Blaize

Gents, I have been asked to help a guy with his MS and thought I would ask here to see if any of you have run into this before and have any idea's. Car is a 1995-6 1.8 with a mini cooper charger on it. M/S1 3.0 pcb, built by a 3rd party as per brainiacks write up.

It runs fine but the tach is playing games. When cold everything is ok, but after 2-3 min of running the dash tach starts to hop all over the place. The M/S gets a clean signal all the time and the datalogs come back fine with no spikes or odd readings. But the tach is hopping all over the place. Now this is a 1.8 so I know the coils work a bit different than mine (I am 1.6) so just plugging my MS in with his map in not an option right? Any idea's?

richyvrlimited

iTrader: (1)

Bad earths, even stock cars do it, clean up the ground near to the throttle body.

From the year it's likely still a 4 pin coilpack, so the tacho is fed from them, you could build a tacho output circuit and feed it from the ECU, that may help, but I'd do the above 1st.

Braineack

iTrader: (62)

Your dash tach gets its signal directly from the coils...

Sorry, read your sig and not the post

richyvrlimited

iTrader: (1)

it's a 95-96, so it may be a 96 with a 3 pin coilpack and fed from the ECU, then again it may be a 95 and fed from the coilpack

Blaize

Yeah, sorry I don't know the exact year. I "think" its a 95 but not sure. I'll have a look at the grounds then and see if there is anything there to be corrected

Joe Perez

iTrader: (8)

Look at the coilpacks. Specifically the low-side electrical connectors going to them. Does each connector have three or four wires going to it?