bushytails

Could be a broken cam between 1 and 3.

yay! :)

And did it fix the problem?

"Any suggestions on common causes" The most common cause... it's almost 40 years old. :) Lucas can help slow oil usage, as can switching to 10w40 or 20w50. If the turbo is leaking, replacing it is probably a good first repair step.

Your wheel bearings are shot, the hub nut (big 36mm hopefully with a cotter pin) is loose, or both. Jack up the wheel, release the e-brake, grab the wheel top and bottom, and wiggle. If the whole axle wiggles, including the cv joint cup, your wheel bearings are bad. If just the drive flange wiggles on the axle, your hub nut is loose. Remove cotter pin, put tranny in 1st, tighten until engine starts to turn, put e-brake on, tighten until e-brake slips, lower down, tighten really bloody tight (150ftlbs), keep tightening until cotter pin goes back in. This multi-step tightening process is to make sure the drive flange ends up centered on the shaft and bearings - if you just crank it down with weight on the wheel, I've had them end up crooked. Edit: Another thing I've seen is your caliper has come loose (bottom bolt backed out) and is rubbing on the wheel, but that usually causes loud clunks and occasional lockups, not grinding and occasional lockups.

I too hate drum brakes... That's why I don't have any anymore! :P

That's for the fairly rare Carter 1-barrel carb. You could get a matching Carter 1-barrel, or slap anything else on for a good horsepower gain. A 49-state Hitachi is the easiest manifold+carb swap, and parts are easier to get. EA81, not EA18, BTW. If you have access to TIG welding, you could probably weld on a generic Weber converter kit. Here's a Carter that might bolt directly up: https://www.ebay.com/itm/168145191200 Listing doesn't say what it's from, but it looks like the right mount, and even the correct subaru plugs, so it might be an exact match. But, as I said, you'll get better performance with a Hitachi intake swap, and much much much better parts availability.

I had an EA81 for a while where every couple months I had to add a bit of oil to the dist to keep it quiet...

It's plugged on GLs, and has a switch on DLs, as the text says. Note the thread is 1/8 BSPT, not 1/8 NPT, but they're similar enough it usually fits. Also note if you swap in a DL engine into a GL, and then plug the wire into the switch, where the wire is exactly the length and position and connector to plug onto the switch, you cook the dash gauge. Seen that done twice now...

The spring clips need to be pushed in so they go in the notch in the pad, not sticking out on top.

I think there's a hidden filter in the injector. You might try seeing if it's got a chunk of decaying fuel line or something stuck in it, that might happen to the new injector.

The IAC has no effect at open throttle, so it's easy to rule out anything to do with it.

I'm thinking of the mpfi version. they were still doing spfi in 93? Shows how many of those I've worked on. lol Sorry, my bad. egr valve stuck open?

I haven't troubleshooted that problem on one of those, so just some random ideas... Does fuel pressure go up to 35+ when you give it gas, and stay there as the rpm drops? Did you recently get gas, or other chance of contaminated fuel? Sample a bit into a clear container from the pressure test port if not sure. Does the exhaust coming out the rear feel normal, with distinct pulses per cylinder as it idles? Does it feel like all cylinders are weak, or like one or two cylinders are cutting out? Coolant level and condition normal?

I hate trying to remember things. It's not like I've done this several dozen times or anything. lol. I'll try... The thumbnail (I haven't watched the video) shows the drive flange and caliper mount removed. Don't need to do that if just doing pads. The only bolt you need to remove is the little one on the bottom caliper slide pin, then rotate the caliper up. Squeaker goes on inner pad bottom. If you use the pad from the other side of the car, the squeaker will end up on top, and gets mushed by the caliper and makes noise instantly. Pads go in bottom first, push the spring clip in so it goes in the notch in the pad, angle the top of the pad in, do the same with the upper spring clip. The pads will sit perfectly flush and solid on the rotor when the clips are all properly sprung. Any wiggle at all means one of the clips isn't in the right place. Regrease the slide pins every time you do brakes. On the top one, slide the caliper off, wipe the pin clean, coat with fresh high temperature grease (ceramic, often purple - not wheel bearing grease), put a bit of grease in the caliper, slide caliper back on. For the bottom pin, pop it out from the boots, do the same thing. Failure to regrease will cause them to get sticky and trash your pads. Work back and forth and pop boots back on once sliding nice and smooth. A bit of brake fluid also works well for lubricating the boot. Spin the piston in with any available tool until it's almost flush with the casting. Align the piston so the V notches face parallel with the claws, that is, the short way across the caliper, which will be radially in and out when the caliper is installed. When you rotate the caliper back onto the pads, there's a bump on the back of the inner pad that needs to end up in one of the notches. If you have the piston rotated the wrong way, it will end up on top of the bump, and may mush the piston or your brakes will suck until it self-rotates until it lines up. If the piston is difficult to spin in, the caliper is crusty, and may also drag. If you spin it in, then step on the pedal three times to push it back out, then spin it back in, etc, a few times, you can get it sliding a bit better. Or wear your seal out more. One or the other. Spring clip kits are still available and are dirt cheap if you need them. After you put the new pads in, and spin the piston back in, making sure it's rotated to the position where it'll sit over the bump when you tilt the caliper back down, tilt the caliper down and reinstall the bolt in the lower slider. You'll usually need to push the slider pin back a bit to get the caliper down, then wiggle it around to line the bolt up with the hole. Then, with the car off, step on the brake pedal several times until it gets solid. Then do a visual inspection to make sure the pads are still sitting perfectly flush on the rotor. Then put the wheel back on. The brakes will suck at first; I usually power brake for a little on a quick test drive. You may need to step on the pedal hard a few times to get the e-brake to adjust, depending on caliper crustyness level.