Okay, what all is needed to replace my ignition system?

dotorg · 07-10-2003, 02:39 AM

So I haven't tried firing her up this morning (condo complex, 6am, people would be pissed)

For those who didn't see my post last night, I finally drove my car home last night (yay), and it drove fine except for some misfiring above 4k (boo), stopped and started a number of times, until I got home. Moved my other car out of the garage, and it wouldn't start. (crap)

So I was told to do some basic stuff... make sure its getting fuel (I think it is... last night when I was trying to get it to start it would crank and crank and crank, then stumble a bit, but not fire... I figure it wouldn't be stumbling if it wasn't getting any gas. I can hear the fuel pump anyway... I was also told I should check timing (oops, no timing gun, need to get one!), points, loose wires, etc. Maybe replace the cap/rotor.

So this is really confusing. I took the cap off this morning, and while everything looked familiar from tuning small block v8's in high school shop class, I seem to have killed some brain cells in college and don't remember a bit of it. I pulled out Wayne's book, hoping, for example, to find a picture with an arrow saying "this is the points thing everyone's been talking about". No luck. What the heck are the points? Are those the nubs up in top of the cap? Mine look grimey if so.

Anyway, I'm confused. The car had a jacobs milagemaster and ultra coil in it originally, and they were pulled out because the PO couldn't find the tach adapter he bought, and I wans't comfortable driving a car I didn't know the "sound" of without a tach... so its back to a stock coil. I was going to put it all back in since I have the tach adapter now, but the mechanic to built the engine in there recommended the MSD unit, and suggested I sell the Jacobs stuff. He said its an easier install, and he's had better luck with them. Okay, I think, I can probably do that. Unfortunately I don't understand what all is really needed to do that. Last night sufing here I found out about these optical ignition thingamajigs, that make me not even have to know how to adjust dwell and stuff. That sounds good, too.

So here's the crux of my question. (Yes, I've searched the archives, and all the posts here seem to assume a bit of prior knowledge about this stuff I don't have). I need a basic kindergarden explanation of what exactly I'd need to change to replace the ignition system with one of these optical things, and multi-spark coil things... Use small words, I'm a ECU map kind of guy!

And if anyone has a picture of "points" and can load it up in Paint or something and circle one of these bad boys, post it, so I know what the heck I'm supposed to be looking at!

(Oh yeah, 2.0L 1968L motor, recently rebuilt with S cams, and some other stuff... I'm 99% sure its a Bosch distributor since its not a real tall cap like the Mirelli ones I've seen)

McDaniel · 07-10-2003, 03:24 AM

here is the pic of a set of points from the Pelican CD.
Price is $8.20
Also by scrolling up and down at this link you can see distrib
cap and rotor button.
Good Luck!

F:\pelicanparts\catalog\shopcart\911E\POR_911E_ign iti_main.htm

dotorg · 07-10-2003, 05:21 AM

Quote:

Originally posted by McDaniel

F:\pelicanparts\catalog\shopcart\911E\POR_911E_ign iti_main.htm

I don't think that URL is quite right.

McDaniel · 07-10-2003, 05:44 AM

Sorry, I did that off the CD catalog they send with parts shipments which was in my F: drive. Go to their on line
catalog and look under electrical. It shows all the info
I mentioned.

dotorg · 07-10-2003, 05:52 AM

Yeah I just went digging. Informative, I had no idea thats what I was supposed to be looking at.

dotorg · 07-10-2003, 09:55 AM

Come on, I know lots of people have done this... someone just post a list

All the websites selling these things (and for that matter, the manufacturer sites) aren't terribly informative about what you need, and what works together with what, so its not clear what is actually needed to get things working. Optical box like the XR700 with stock coil? With MSD box? Do you need a coil in that case? Which coil if so?

Everyone running this stuff, please reply with what the hardware you're using is. There's a lot of posts in the archives, but I still can't find a good explanation of what is really needed and why.

Ugh I hate being a noob.

On a side note, do programmable ignition controls exist? (Like an ECU, only just controlling ignition/timing, not fuel injection?) I'm just starting to figure this stuff out, but it sounds like the distributor design determines your timing curve, so your fuel requirements and agressiveness of the timing is largely set in stone based on the distributor you're running. Is that correct?

My dream box would be something I can plug into the distributor that replaces all this electronic stuff with a box I can plug into my computer to map throttle position and rpm to a timing value... That way I can have 87 octane, 94 octane, and "oops, this leaded 112 octane is street legal, right?" programs.