Today I took the shortest, slowest test drive of my entire life... and it was awesome!!!
After spending lots of time (and a few tool runs) trying to modify the donor van's trans cable bracket into something I can use, today it finally hit me: it simply isn't going to work. Okay, start again from scratch. With an open mind, I came up with an idea so simple that I couldn't believe it hadn't occurred to me until now. Half an hour later, I had (at least partial) shifting ability. Close enough for now.
I fired up the car and got the engine fully warmed up. While doing so, I noticed my shiny new radiator's equally new cap was leaking coolant. Hmm. Easy enough to address later.
With the engine warm, I shut it down and then began testing the fusebox for an ignition source which is live in both ON and cranking. Once I found that, I fed it into the relay for the TCI trans controller. At last, I was ready to bring that controller online. Ignition on, I went through the setup wizard and everything seemed perfect. After I let it store the 'new tune' I re-fired the engine. Immediately, the TCU barfed a fault code. What?!? It gave me a TPS error. I shut it off and dug out my multimeter, and I started testing each wire at the sensor. Everything was right on spec. When I installed the sensor, I followed the TCU instructions and tried to position it so that at "zero throttle" the sensor was putting out a very small amount of voltage. Now as I checked on that, I saw the sensor was actually putting out 0.0v at idle. Ah-ha. I dismantled the TPS assembly, modified it to make sure it was slightly engaged, and reassembled everything. Key on, go through another setup wizard, save the new setup, and start 'er up. At last! The TCU is happy and reports no errors.
I left the car idling while I began cleaning up my tools. With that done, it was finally time to get the car off the jack stands and back on the ground. I decided to lower the nose first since the jack was already under the engine crossmember. With those two jack stands out of the way, I lowered the jack... only to have the weight of the fully-operational big block push the crossmember low enough that the jack was stuck under it. (sigh) I noticed the left front tire was a bit low, so I routed my air hose from the garage to the front end and inflated both front tires to 42 psi to try and add more clearance. Better, but still not quite there. I went next door and got my neighbor to lift up on the left fender while I yanked the jack from underneath, and that worked. The tail end sits considerably higher, so there was no problem with that end.
And now, finally, I was ready to go for a drive. My plan was simply to drive around my block, nothing more. In eager anticipation, I hopped in and buckled up. I put my foot on the brake and shifted into reverse, then very slowly backed down the driveway onto the street. I shifted to neutral just to see if it would work as desired (it did), then shifted to Drive. I eased off the brake and started on my way. Even at idle, I was picking up a little speed... and just as I was about to actually apply some throttle, I suddenly heard a soft thunk-thunk-thunk coming from under the car. I quickly braked to a stop and the noise stopped as well. I let off the brake, and the noise came back. Hmm. It definitely seems to be a driveshaft noise. I had only made it to in front of my neighbor's house (the same neighbor who helped me get the car off the jack), but I decided my first drive was over. I backed up to my driveway, then pulled right back in next to the house where I had been just a minute before.
Obviously, I have a few issues to address. But you know what? I don't care. It actually moved under its own power! I am so stoked.