DaveT

Ok... It's better. But something else is also contributing. Slight intermittent skip at half to full throttle is when it showed up. Maybe half as bad as before cleaning and testing the TPS.

Ok.. I decided to check the TPS first. Found one of my spare engine wiring harnesses, and separated the throttle cable. The pins slide out the back of the big round connector when you use a jewelers screwdriver to lift the locking tab. Got one of my spare TPS units. Carefully opened it up, these things are well made. 50 years of designing and building electronics with potentiometers, you get to know a well made pot.... Anyway, it looked good, so I cleaned a little glue off, and reassembled it. Trying to check for a flaky pot with a digital meter, as usual, is nearly useless, so I thought about it for a minute.... The easiest way to find a noisy pot is to listen to audio going through it, so I rigged connections from a music source through the TPS, to an amplified speaker. It worked great. Also checked the throttle closed switch, good. Bring the test rig up to the car, and plug the connector onto the TPS. Instantly, I have no ground continuity, music at full volume! wiggle the TPS connector, crackle, no volume, crackle low volume. Well, there's a problem! Never would have found it that quick probing a meter on the pins, since the probes would poke through any oxide, etc. I used my tiny wire brushes to clean the pins, cardboard to clean the sockets in the cable end, a little contact cleaner on both. The test connector now works as well as it did with the reference TPS. Volume goes up and down smoothly with no crackles with throttle position. Tomorrow, I'll take a drive to verify if this is the total fix.

No check engine light. No trouble codes. I forgot to check those before my first post, but yeah, none. [it's been a while since I had a failure that caused a CEL / code without some other obvious clue.] Injector wires, sounds good to check, TPS I was thinking of checking also. I keep thinking it's a 30yr old potentiometer, it could be worn out. Regarding the post from 6star - if the poor running is engine temperature sensitive, check the CTS. Search for my post about CTS, I have listed several values & voltages for good ones. They do fail in ways that do not trip trouble codes.

I've been hunting the cause.... I've got a new fuel pump, and regulator with a gauge I can read while driving - the fuel pressure is good. It will climb a long hill from a stop, floored, 2nd gear [3AT] but occasionally stumble once the RPMs get up. Not constant, just a glitch now and then. Sometimes on acceleration from a stop, a little trip before it gets going.

On your last picture- If you remove the bearing holder, you will have to re set the bearing pre load / pinion & ring gear alignment. Maybe if you carefully, mark the position, and count turns while removing you could get it back where it was. I have not tried this. I have read the FSM directions for assembly, it doesn't seem trivial / fun to do right.

If ypu never had the intake off, or it wasn't put together with anti seize, run it till it's up to temperature before loosening the bolts. Saves snapped bolts.

One of the intake manifold gaskets could have failed. Or the weird o ring under the throttle body. Either could supply enough coolant to make a big smoke show.

I never saw a 1 v pulley on an EA82. At least 1 pump I have, the hub for the pulley can be pressed to whatever height is needed.

I noticed looking at a couple of oem ones I have laying around there are 2 slightly different kinds.

I'm not xt specific. But starving for fuel can do that. T in a pressure gauge after the last filter. Other thing I had do this was the guts of one of the catalytic converters broke loose, and mostly blocked the exhaust. Both of these were intermittent when I had them happen. The test for the exhaust is to loosen the y pipe bolts on the studs to get a gap between the heads and the pipe, like 1/2". It will be loud. But if it runs great, the exhaust system has a blockage.

I replaced the balls in one of my oem ones. The cup was good, the star was ok, but the balls in this one had taken the abuse. I got new ones, re assembled it, so far, so good. Keep your eyes open for used oem, but it's going to be tricky depending on where you are.

OEM axles are painted dark green on the cups. Unless they are extremely trashed, clean, regrease, reboot. FAR better than aftermarket axles. Do a few searches on here for all of the past threads with horror stories about aftermarket axles. CVJ / half shaft / front axle.

I don't know those specific ones... Some motors & alternators have a small hole that you put a piece of wire through to hold the brushes back.

referring to the picture in the Jan 3rd post - the tab that the wire connects to broke off of the thermometer thermistor for the temp gauge.

Check the CTS. Coolant temperature sensor. Should be a 2 wire thermistor near the thermostat housing.

The emergency brake on the front wheels is the clue. The calipers do not push in. The piston needs to be screwed in.

It sounds like it has been sitting for long stretches? The idle passages could be gunked up. I don't see anything in your destination that Points to electrical / ignition problems. I don't know specifics about EA81s, I skipped over those years. EA82 Hitachi carbs are a real problem to rebuild.

I had one front diff run dry, leaked out the axle stub seals. The dead bearings wrecked the inside of the front case section. The oil pump shaft just slides out. The dissasembly starts at the rear end. The transmission parts are likely still as good as they were when it was running. The diff is seperate, uses gear lube. The seals between the diff and the transmission sections are probablyruined also.

No knock sensor on SPFI.

I've never had the O2 do anything but cause emissions failure. Could be mildly starving for fuel, T in a pressure gauge. 21PSI, no less. The CTS can cause drive ability problems, but usually it will run ok hot OR cold. Or random / intermittent. I have never had a MAF problem. Also, check the wiring from the sensors to the ECU. They can fail also. BTDT.

The top pic is a jack block I made from plywood. The bottom pic is the proper front jack point. Notice the 2 little notches in the pinch weld. Between them is where you put the Subaru jack. There are a similar pair of notches back near the rear wheels.

There were 2 different final ratios in the 3ATs. My 86 had slightly taller gears than all of the ones I got later, from 88 through 93. The 88 up do about 65mph at 4000rpm on the flat. To go faster, you need more rpm. The 86 was something like 500 to 600 rpm lower. Also noticably slower acceleration, and bog down on hills more. More HP would level that off.

From what I can see in the FSM, the thing on top of the thermostat is the Auxiliary Air Valve. From one of the diagrams, it would let air bypass the throttle plate. Didn't find much describing why / what it does.

Looking through my 86 FSM, [includes the MPFI turbo EA82] the Coolant Temperature Sensor is screwed into a coolant manifold from the top. It has a rectangular 2 pin connector as part of it. It's good to test these sensors, not replace them, unless you have a lot of cash. I have posted a list of readings from my MPFI sensors and FSM test points, but I do not have any details for the MPFI Turbo one, it is a different part physically.

The single terminal one is only for the gauge on the dash. I have to see if my FSM shows the one for the engine control.