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RPM signal

Posted: Tue Jan 12, 2016 3:21 pm
by Zaphod
As mentioned elsewhere I have a Mercedes CLK320 that I am working on, all the bits are installed and plumbed in with the exeption of the last three wires

The RPM one is probably the most important of those left, but the car has a coil for each plug, but just to add to that it actually has 2 coils for each plug, so the earth for one cylinder may not work terribly well, is there an RPM signal at the ECU I can use?

the other twop are the left and right bank lambda, which I would like to have, ideally to be picked up at the ECU end of the loom

Re: RPM signal

Posted: Mon Feb 01, 2016 2:36 pm
by scottyf
Should be fine just taking it from a coil lead negative. Can't see why it wouldn't work.

Mines a wasted spark system so actually fires every cycle of the bottom end and the software compensates for it.

Re: RPM signal

Posted: Mon Feb 01, 2016 5:52 pm
by LPGC
Yeh like Scotty says, no problem wiring your OMVL system rpm wire to any of the coils - and that's the way I'd do it, unless you have an ECU pinout diagram which shows an rpm out for (say) tacho.. Depending on year of your car there may not be such a pin.

Simon