I finished fabbing the new roof rack rails, sans crossbars.
I installed the new fuel injectors, upgraded from 1-hole to 4-hole Bosche injectors. Many people report an increased MPG or two after this upgrade.
After that doing that I reset the "adaptive memory" of the ECU/PCU/PCM/whatever. It's supposed to make it re-learn the correct settings now that it has better fuel injectors, but that may be a wive's tail for all I know. Either way I'll need to go through at least a tank of gas before I see improvements as it runs rich while it's still re-learning and it says it can take 50 warm up cycles or 500 miles before the adaptive memory tables are populated again. So far the idle feels a little smoother but I'm not noticing much else. The old injectors looked like the OEM ones but they didn't look too dirty and I've ran a few bottles of SeaFoam through the gas to keep them clean, so maybe this wasn't much of an upgrade. We'll see.
I also removed the plastic pieces behind the rear wheels. I'm still thinking about what to do with the sheet metal there, any one care to provide some insight? On one hand, it seems to me that freeing up the airflow there can help a lot - it would be like an extreme mud flap delete. But on the other hand I don't know squat and all the examples of trucks with good aero - like the Phil Knox truck - make me second guess this idea for sure.
Or maybe the air is so disrupted by the front of the vehicle that it will never have a chance to smooth out and take advantage of any aerodynamic enhancements made to the rear of your jeep.
Oh, and there's rust that would be best cured by cutting it all out. And obviously something must be done about that rear bumper...
I'm gearing up to do a light engine overhaul.
I'm going to do the mechanical fan to electric conversion. Stock for 1997 is one 15" mechanical clutch fan, and 10" (I think) auxilary electrical fan that only comes on when temp gets 220*F. I'm still deciding if I want to replace the mech fan with one 16" electric fan, or replace both stock fans with three 10" electric fans.
While I'm doing that I might as well replace the radiator since I'm having problems with it. And while I'm doing that I might as well replace the timing chain - it gets a little loose after so many miles and the valve timing can suffer. So they say.. I'm also looking into have the engine professionally cleaned via motorvac service. Maybe I can also adjust the valves/tappets and stuff.
So here would be the new serpentine belt diagram after deleting the AC compressor and mechanical fan pully:
Not only should this free up a pony or two, it's also much better for the alternator because, in the stock location, it's too close to the ground were it gets blasted with water, mud, salt, etc. and it's always one of the first things to die if doing water crossings (driving through shallow streams). So it's a win win. And maybe I can get a lower-resistance alternators - do they make such a thing?