BMW Ignition Maps, and tach question...

[Barry_D]

Hello all,

It's been a long time since I've posted here, because my project has involved my whole engine. My 1974 2002 BMW 2.0L engine now has modified 318i injection, MJLJ & a MegaSquirt.

I fired her up yesterday for the first time since the rebuild, and the timing is way off. The MegaSquirt also needing it's config reworked isn't helping things...

Today is tuning day 1 so I thought I'd post to hopefully find a better map to shorten my MJLJ tuning time.

I'm also not getting a tach signal like others have talked about, so what are my options? Do I hook up my tach to my coil pack using 2 1n4004's and a zener like in the graphic here on the site?

If that's the answer could someone explain that a little? Would I be soldering and running more wires off the coil packs? I don't get it...

[Todd Charles]

Others may disagree with me but I would start with a "mechanical advance" curve then incorperate a vacume advance later. Do this by setting your RPM bins between 500-3500 rpm then set your MAP bins from 10 to 100. Fill the MAP bins all the same under each RPM column. Start at 8° or so then work yourself accross the RPM bins to a max of 32-36° at 3500 rpm. Later you can increase the timing on the lower load MAP bins to improve fuel milage and some drivability. Note, these intructions only apply if you are not running forced induction.

Near as I can tell you just need to "tap into" the coil wires. I plan to this back at the EDIS module if I have a problem with my tach.

Todd