DaveT

Plan on going through the entire cooling system, it must be 100%. All of the several hoses, radiator has all fins, not clogged etc.

How old is the battery? How many miles on the alternator?

Crank angle sensor is in the distributor. Spray a second or 2 of carb cleaner into the throttle body. Hold oedal down. Crank. Does it fire?

Low oil. Low coolant. Run on highway until poor running. Then dies. Not good.

There might be a link for the schematics somewhere on the forum. Or maybe the whole manual? Am am not sure, since I've had them since I bought my first GL. I have not seen this as a common failure, or read about it here often, if ever.

I've towed 1000lbs with a GL. That's about the limit. Never went more than a few tens of miles. If you consider it, a very thorough cooling system inspection and maintenance would be a good idea.

I have not had that particular failure. Yes, some parts you are better off with oem.

I've ocasionally ended up with odd pairs of tires. I ran them during non snowy months mostly, switch the 4wd on momentarily if I wanted extra traction on rain for a quick start, then right back off. An advantage of switchable 4wd over awd. But it's definitely better to have all 4 the same.

The 3.7 vs 3.9 mismatch is hard to miss. I drove mine with that for a while before I had time to swap in the correct transmission. Are the 4 tires the same model and wear? That can make drag also, but not as bad as the gear ratio miss match.

+1 what grossgary wrote. When I added 4WD to my 87, I made that mistake. It would bind a lot on dry pavement. It would be squirrely in snow. I swapped the transmission with another, and it's normal now. In my case, the 4wd transmission that had the odd ratio was from my 86 carbed 4wd. All of the others I gave are 87 and newer version, and have the same ratio, but different from the 86.

One of the original Subaru selling points was shift on the fly into 4WD. I do it frequently. Get used to your car first, to be sure everything is correct. Hard turns are not the best time to switch. But straight cruising along, not heavy load, is no problem. Everything is already turning at the same RPM anyway.

Another possible path is through the main alternator output wire. Partially failed rectifiers can do things like that. Simple to check, just un bolt it. But it is live if the battery is connected, so pull the GND (-) side first.

If I'm following correctly, the timing belt was done at 75k. The engine is now at 160k. It's now close to 80k on that replaced belt. So you replaced it just now? (Which is good).

Tires all the same size and molage? Did you just get this car? Did it used to work normally? You should be able to switch 4wd on and off at will going straight. No noticeable change in loading, if everything is correct.

On interference engines, I have only used OEM for timing parts. Not worth the risk..

I don't know anything about alldata. Go by the FSM, plus experience from people on the forum. Details needed. Which engine? Did you replace all of the idlers and tensioner? Did you use OEM or high quality kit? Did you work ALL of the air out of the cooling system before going for a drive? This is not a simple process, and a large air pocket is a likely cause of the overheat. Wouldn't hurt to know mileage. Have headgaskets ever been replaced?

The CTS tells the ECU what temperature the engine is at. It's the one with 2 wires. The sensor for the dash gauge is a one wire sensor. They are separate. See what comes back when you clear it. Check the connections and wiring in addition to the sensors. The FSM has testing details. If a sensor is bad, it's pretty much done, unless it's a wire broken off kind of thing. Possibly some failures of the Throttle Position Sensor could be fixed.

Oh, the ECU numbers are all visible on a label located in the center of its cover. Just have to remove the plastic panel, and look. I've never reinstalled that panel....

The shaft seal on the oil pump can be replaced. The fel pro conversion kit has one in it.

Not directly - cylinder to cylinder... I guess depending on what the valve positions are in the adjacent one, compression would get pushed out intake or exhaust. Not sure how that would pick up oil. Leakdown should be interesting.

I took a look in one of the know ECUs the 88 - Quite different from the one I started with. I'll add more info about that tomorrow. Hopefully, we can identify what cars the flatter ones came from, as they don't seem to match the others.

Some things to think about & consider: Exhaust manifold being loose has nothing to do with compression test results. Compression that low should show up as poor running, I would think. Blown head gasket would almost certainly be blowing exhaust gasses into the cooling system. Except, if the 2 cylinders have a leak between them, which would also explain them both having the same low reading. Lots of blow by can push oil up everywhere. How many miles on the engine? Might be worth checking the timing belts / marks for proper orientation.

Here is a list of ECU part numbers and cars they came from / are in. Looking for patterns, and more data from any other out there, if you can read yours and add them, that would be good. GL / Loyale SPFI ECU numbers / versions. Assuming 49 state unless marked otherwise. 1987 2WD 3AT wagon [4WD added] 2261 AA200 MECF – 011 7122 3E Big letter to the left = N Painted ECU 1988 4WD 3AT wagon 2261 AA390 MECF – 021 7805 3C Big letter to the left = 18 Painted ECU 19?? 4WD ?? wagon 2261 AA100 MECF – 001 5Y14 Big letter to the left = E Painted ECU & flatter case 19?? 4WD ?? wagon 2261 AA102 MECF – 002B 6429 Big letter to the left = R Painted ECU & flatter case 1990 4WD 3AT wagon – not 100% sure, just by process of elimination 2261 AA394 MECF – 023 9Y27 G5 Big letter to the left = A9 Gray ECU 1992 4WD 3AT wagon 2261 AA395 MECF – 025 1X03 H7 Big letter to the left = J4 Gray ECU 1993 4WD 3AT wagon - California market 2261 AA395 MECF – 025 2622 H7 Big letter to the left = J4 Gray ECU I have one from a 1987 4WD 5spd d/r wagon, one of the unknown ones. I have one from a scrap yard, probably a wagon, don't remember. I may have another floating around that I can't locate right now.

You are looking for Fel Pro number HS 9392 PT-2 and CS 9390 for the conversion kit. Amazon and a lot of other places sell them online.

Fel Pro have a good reputation in general on here, I've had good luck with them.