She lives!

[AlponaBMW]

As of 10pm Saturday the M42 powered Chump runs!..just in time to head to the bar and watch F1.  Looks like it'll be a great season.

It wasn't without electrical drama at the end:  First time we held our breath and flicked the master switch poof instant cockpit full of smoke.  While wiring up the re-located alternator I decided to ditch its plastic wire guide which of course made B+ AND D+ very effective grounds:)

Second power-up: Master switch on, no smoke..Ignition switch on, no smoke..Start button pushed, engine cranking, no spark:(  After an hour of brainstorming and checking sensors etc it all looked good.  We were stumped and decided to re-install the stock chip.  Opened up the ECU and found the performance chip installed backwards.

Fired up instantly, great oil pressure, no leaks.
BTW, pin 74?..nothin.

[DesktopDave]

I love the sound of a dead car starting in the morning!

LOL...not a performance chip there, eh?  Did it come back?  They're usually fairly robust.

Yup, I've done the alternator/starter unfused power sparky-jumpy-ouchy bit.  Have a few spot welds on my 1/2" ratchet to prove it.  I tend to disconnect the battery as preventative therapy now.

I have no clue about pin 74, and I've looked.  I'm not even sure if it's an input or output signal.  It does sound possible though.

[AlponaBMW]

With everything buttoned up Sunday afternoon There was time for a few very rural +100mph runs, and time to do a little more electrical testing of that mysterious  pin74 (engine speed output to the stock tach) while the motor was running.

Turns out 74 is not a pulsed ground signal as feeds a traditional tach, nor a pulsed positive, but rather a variable low voltage + very similar to that of the crankshaft speed sensor..in fact it may be that very same signal passed along by the ECU with either no processing at all.  Stock 318 tach is simply a voltage meter.

So probably no tach for the race on April Fools but the chip has a soft rev limit at 7K anyway.  The tach is really only usefull for describing either a problem, or comparing shift points and track strategy with team mates.
-Mike

PS I can now officially announce that with the very minor mods I described before there is zero problem running the 2002 flywheel and clutch assy..and no the slave pushrod does not need to be shortened at all.