Fuel Piggy-Back Wiring & WB-O2 Q’s

[Gavin]

I have a Split Second PSC1-003 signal calibrator that I’m planning to use to adjust AFM signal (while I modify my fuel set up). To install the unit I’d like to tap into the ‘AFM’ ECU input signal and ‘Tach’ output signal at the main ECU terminal connection point.

Can anyone tell me what wires (colors/terminal slot locations) I should tap for ‘AFM Signal ECU Input’ & ‘Tach Signal Output’ at the ECU main terminal connection?
(I have the 55 pin Motronic 1.1 ECU, in an 88 325)

Also, I’ve just finished installing a wideband O2 sensor & gauge in my vehicle (the sensor was installed where the two factory collector pipes merge). The gauge usually reads about a 14.5 AFR, I don’t assume that BMW has designed the SETA to run this lean, and I’m betting my gauge needs calibration, but I thought I’d ask: What should the factory AFR sit at?

[rs4pro3]

pin 7 Gray/Yellow-Air flow input to the ECu
pin 6 Black-Engine speed output to the tach
pin 1 Black-Timing control to the coil(tach signal can be pulled off either these pins)

[Gavin]

WOW. That was quick and very helpful.

I appreciate the assistance rs4pro3.

Now if anyone can tell me what AFR I should be expecting to see, I’ll be all set.

[Gavin]

Thanks for the help rs4pro3, fuel piggy-back installed...

Next up: ‘i’ head on my SETA bottom end, and installation of my home-made ITB’s (It’s been a hell of a long time coming).

[craz azn]

home brewed ITBs?? I'm listening :)

[Gavin]

I actually completed all the fabrication work a long time ago – port matched & chopped down a spare intake manifold, then spaced out & welded on a series of GSXR 1000 throttle-bodies – I’ll be sure to post some pictures once it’s installed.

[Gavin]

A quick teaser shot of my ITB progress to date