It runs now! (pulls liike a beast too)

[christer.medin at lennoxintl.com]

Well, yesterday we fixed the annoying stumble! (Well, needs to be properly fixed still, read on..)

After checking, double-checking and triple-checking most mechanical stuff, replacing the plugs, and replacing a plug wire that had a small cut in it, we figured we had covered most possibilities as far as purely mechanical problems.  Spent most of the evening building a $7 Lowe's special PVC cold air intake, hooking up the Haltech computer to the fan relay so it could control the fans, and other small odds and ends.
Took it for a drive... stumble was STILL there at 3K.  Since I had this gut feeling (which I should've followed earlier, but it seemed so unlikely) that whatever was happening was tied into the timing advance going in in full, I suggested we bump the advance curve up a bit to see what happens... so set it to pull in full advance at 4K instead of 3K, and guess what?  Thing pulled like a monster all the way to 4K or thereabouts.  Hmm. :)  Next step in troubleshooting was to see if the problem was related to _when_ it puts the timing in, or _how much_ timing it puts in.  Set it back to full advance at 3K, but dropped down max advance to 32 degrees from 38... (tried 36 the day before without curing the stumble) -- stumble was _gone_.  Roads were a bit wet, but we hit 4500 RPM or so a few times without a single misfire.  Since we'd been beefing up the fuel maps the day before, the o2s were in the 850-860 range consistenly.
The problem?  Looks like it's related to 'rotor phasing'.  I don't know squat about how the reluctor wheel/sensor in the distributor works (seems like it needs to be adjusted), but having come this far and learned so much, I have faith that we'll figure it out :^)  Whoever mentioned the rotor phasing deal yesterday on the list, thank you -- I learned about it flipping through the Haltech book and there was an appendix mentioning it, which caught my eye because I had read that very term only hours ago. :^)
So, as it stands, the car runs well and can be driven around, which is great because my friend needs it to get to school and back, and had to borrow a beat-to-hell pickup from a buddy for the last two weeks. (Lesson in this, a 3 day engine swap can turn into two weeks of changing the intake from TBI to TPI, installing a dfi setup, and getting the thing to run right...)
Few things to address: Once the car warms up, it idles around 800-850 rpm which is right where it should be with the cam (220/228) that's in it.  However, before that, it sits around 600-650 rpm and stumbles a bit... we set the Haltech to 800 rpm base idle, and 300 additional rpm when cold.   However, that doesn't seem to change things one bit.  It's a minor thing (relatively speaking) though, so it's more of a nuisance than anything.  Also need to set the converter lockup map up to where we want it, and do some overall fine tuning.
Thanks to everyone for suggestions and support the last few days, this has been the first time we've ever messed around with a DFI setup, so it's been quite the steep learning curve ("what the heck does THIS parameter do?").  Now that we know how to set it up, though, I may just have to get a Haltech to run my future project car...

Christer