DaveT

Today, so far.... Capped the small vacuum port on the passenger side that powers the egr, and the hvac controls. Capped the brake booster port. No changes. A couple of the short hoses were hard, so they will be replaced. Tried injecting propane into the intake boot - via the crank case port in back, and the one for the IAC, and into the AIC. Made no difference. Pulling / capping the IAC line caused rpm changes. Propane / no propane seemed to have little to no effect. Note, I turned the gas on & off a normal amount for a torch flame, not trying to flood the engine, etc. Unhooked the FAM sensor, pulled the intake boot. I can see gas traveling across the throttle plate to the edges at idle. evenly all around. Looks like it does on my other EA82, which I did the same on. The O2 sensor started off about 0.26V. Calmly dropped to about 0.2V until idle went down to normal after warming up. Moved between 0.25V and 0.5V from there. Kind of jumpy unsteady hard to get good readings on the digital meter due to slow updating. Analog meters are way better at dealing with varying voltages. After a while, it stopped the switching and stayed at 0.25V. Off to do the leakdown tests.

Oh, CO problem. Yikes! Yes, check that out. Somehow exhaust may be getting in.

I'd probably try an oem junkyard one. ECU failures are exceedingly rare.

Water plumps are notoriously bad at moving air. Some Subaru engine / water pump designs end up trapping air in the pump due to the routing of the passages and hoses. Once enough air builds up, it stops pumping.

What Gary wrote.

Ignition timing has no effect on compression.

Sorry, Factory Service Manual.

Torch wouldn't hurt. Once it's bust like that, a weld bead around the inside might just shrink it and heat stress it enough to get it loose. I've used that trick to get stuck outer bearing races out.

If it runs for an hour, the coolant has to be circulating. If the headgaskets were blown bad enough to effect compression, or show wet coolant on the plugs. Or show with a coolant system pressuring check. You couldn't get more than a mile or 2 if they were that badly blown. My comments are based on what I have seen in my own cars, and many threads I've read on here. Hopefully a few others who have dealt with that specific engine will add ideas.

The air passage from the TB to the head is one round tube. The head splits the airflow between the 2 valves. I could see a vacuum leak throwing off 2 cylinders on one side more than the other 2.

The gas test is notorious for false passing. I have yet to hear of any othe cause for coolant to be pushed out of the radiator. The water pump suction side pulls from the radiator. Thermostat has to be at around 190 degrees to open. If there is no flow because of an air pocket starving the pump so the heater loop and bypasses are not flowing, the thermostat won't open. Coolant eventually boils, pushing out the overflow. Sometimes the disturbance will get some water in the pump, and some circulation will then open the themostat, pulling coolant back in.

It is a standard thread. Right = tight.

Well that proves the wires are ok. Might be worth compression checking at least one other cylinder for comparison. It is odd that it is much worse with new plugs and wires. Having a hard time thinking of how that could have bothered the disty. Any chance you cross wired 2 cylinders? I did that once, it ran like crap, but it ran. Just want to rule out stuff before going on a wild goose chase.

The wires are in the harness. They go to a relay board near the fuse box. The oem switch is on the light control stick - I bought a new one from a dealer, and the lights and the relay. Plugged them in and fog lights. With no hack job installation, or huge project to do it nicely. The only thing I'll eventually change is the way the power is routed. The oem setup makes it so you cannot have the fogs on without the headlights. Stupid this is, since in really bad fog, the whole point is to shut off the headlights.

There should be an online FSM for that, you can find every connector in those.

CTS can fail in ways that mess up drivability without causing a code. There should be a chart in the FSM that shows temperatures vs ohms. If it's not steady, and in spec, it's bad.

Put them back together with anti seize coating everything. Come apart no problem next time.

The adjustable front struts have a plate with 2 nuts under the pan that the bottom of the spring sits on.

04 with original radiator? I'd replace it.

That's odd. Try using the old wire on that plug. Or the old #1 wire. The idea is to swap out the wire, to verify that the new one isn't bad. I only use NGK wires.

try finding a factory service manual, or someone who has a link to one. There should be a step by step procedure in there. 1400 is really high, if it's all warmed up. I've never had an 80 with a carb, so I can't be much more specific.

Yes, what happened before the new radiator and thermostats?

Look up the roadkill episode of this on youtube. They did it and dyno tested it. Waste of time.

no hints? Anything look good / bad here?

any arc like you describe is going to interfere with ignition. It is not normal, it's failed insulation.