engine and drivetrain Ignition Advice - blue or black coil? which dizzy?

[josh72ooh2]

I have been told by several people that my ignition set up is incorrect and after some reading on the FAQ, it seems that it is indeed incorrect. Mind you... my car runs OK. A bit slow off the line but fun once she gets going. I don't know what's right or wrong... so i am asking you guys.

The car is a 72 with a weber 32/36. no real engine mods.

it has an ireland eng tii distributor on it with the electronic ign.

problem #1 ? - i have been told that the distributor is too advanced for my car. Works good at higher RPMs but not good on the low.

potential solutions... i have the old 021 vacuum advance dizzy that i could put back in the car with the electronic ignition or i have a 008 vacuum advance dizzy that has a petronix electronic ignition in it (from a parts car). I assume they both have different curves and maybe the 021 is best suited for my set up? i could put the petronix into the 021...?

Problem #2 - Additionally, the previous owner put in a blue coil and wired the resistor with it. I can see that the resistor and a blue coil is a no-no.

If i disconnect the resistor, what do i do with the two wires that are connected to it?

From the same parts car, I have a black coil that says 705 on it. There is no markings on the coil that say Bosch. (see photo). What do i have?

Is it worth hooking that black coil up instead? if so, again, what do i do with the wires that go to the resistor? clip them? connect them?

Given all the parts i have... i'd love to get some advice on what i can do without spending money at the moment.

thanks!

-josh

[PatAllen]

if you have low compression you realy want the 021 dizzy back in there, with the vacuum port connected as well to the 32/36 ported vacuum port, for part throtle timing advance.

do you have the complete 021 dizzy part number ? i am currious. thanks.

[josh72ooh2]

0 231 168 021

do you have the complete 021 dizzy part number ? i am currious. thanks.

[Guest Anonymous]

You have the best of both worlds! I would mount one in heart beat if I had a carb with a vacuum port. 2 reasons: first the advance comes on more slowly so it matches your nominal compression engine better than a Tii unit. Under full throttle you get all the advance you could want. Second under part throttle you get more advance because of the vacuum advance. This is additive to the centrifugal advance.

Have fun

[wegweiser]

About half an hour ago, I removed the Bosch blue coil from my car and threw it in the trash. I'm now running a Bosch RED coil with the appropriate 1.8 Ohm ballast resistor. (These resistors are easily sourced - google "Bosch 1.8 Ohm resistor" to find folks that sell 'em....took me 5 minutes.)

The coil in your photo is black in color, but has printing on it that suggests it's more akin to a BLUE coil (which use no external ballast resistor).

I'd recommend using a stock Bosch black coil with the original resistor or upgrading to a Bosch red coil and using the correct 1.8 Ohm unit with it.

Stick with Bosch stuff. Except spark plugs...I swear by NGK parts in the fire holes.

Things hyped like mad by vendors and still bad for our cars: Bosch blue coils and Platinum plugs. Evil...pure evil.

HTH!

Paul

[kbmb02]

You have the best of both worlds! I would mount one in heart beat if I had a carb with a vacuum port. 2 reasons: first the advance comes on more slowly so it matches your nominal compression engine better than a Tii unit. Under full throttle you get all the advance you could want. Second under part throttle you get more advance because of the vacuum advance. This is additive to the centrifugal advance.

Have fun

That all presumes the distributor is in working order, with springs, weights advance mechanisms working per original spec...

Let me know if you want to have it checked, Josh. -KB

[///mChris]

Did you finally remove the ballast resistor from your blue coil?

If I were you, I'd put the time, energy and money into fuel injection. These problems will all go away. A smart way to step into it would be to run spark only with your 32/36. All you need is the crank sensor, megasquirt and coils.

We could easily get your spark only working in a day.

[josh72ooh2]

Chris, i haven't removed the resistor yet. I'm not sure if i should ignore the two wires that are connected to it or connect them together?

The whole point (of my post) was given what i currently own, i want to make it 'right'... without spending any money.

If i spend money, i am definitely going to invest in something that is compatible for an EFI setup.... and i'll definitely hit you up when i cross that bridge.

[JohnS]

You should read this FAQ, It's an interesting read:

http://www.bmw2002faq.com/content/view/69/32/

It explains why the blue coil is actually a down-grade from the original coil that requires the external ballast resistor (or the resistor wire used on the 1974 and later cars). Basically, you loose the boost function of the coil (during starting) if you set up the blue coil properly. Blue coils work fine as long as you bypass the ballast circuit correctly. On some cars, like tiis, you might want that boost (extra spark) when starting. Best to leave it as BMW designed it. I've found that all of my original "Black" coils are the same as the "Red" ones sold today. My black ones have stickers on them saying that they require the 1.8 Ohm ballast resistor. I guess some 2002's came with Black coils that required a different 0.9 resistor, so check what you've got. Your resistor should be marked on it's metal base with either a 1,8 or a 0,9.

[MMII73]

i want to make it 'right'... without spending any money.

Connect the wires.

[josh72ooh2]

THANK YOU!

the 30 second fix i was hoping for.... but i will probably switch to the other dizzy next time i have a few hours to kill in the garage... then someday, i'll get some modernized ignition control unit to tie into a EFI conversion... someday.

-Josh

i want to make it 'right'... without spending any money.

Connect the wires.

[eurotrash]

Josh, I was forced to go to points and 100% stock ignition. .9 ohm Black coil, etc.. I have it dialed in and the damn thing bump starts and runs just as well as it did with pertronix before it took a dive..