Rough idle until vacuum leak is introduced...??? Bad fuel mileage/power loss?

I have an Aussie YM35RV-MRSBEQ, that appears to have a 2Y engine (the engine number is 2Y then numbers, I was told if it was a 2YC then the engine number would start with that?). Last non-ECU car was an 81 subaru, so I'm very new to this whole 'vacuum hoses running amuck' situation.

On cold start, she runs very rough. No stalls yet, but rough as hell. When I bought it it had a loose hose that I plugged back in, so I figured "hey maybe the owner did that on purpose". Popped it off and it idled fine. Put the hose back on and... it idled fine. Weird. Started again, rough idle. Popped off the hose, good idle. Back on, good idle. No idea what's going on there.

She also had a run-on issue once, and was thirsty as heck for fuel, and blew white smoke at idle intermittently, and sometimes would climb RPM when left to idle after a cold start... So I popped off the EGR valve and yep, pretty sticky. Not sure if it was stuck open or closed, but I filled it with oven cleaner twice, left for 30 mins each soak, blasted out with water and chased the water off with alcohol. Still a bit sticky for my liking but fleabay doesn't seem to stock '88 EGRs for some reason. Anyhow I let the alcohol flash off then popped the EGR back on.

Hasn't run-on (or whatever you call it when you kill the ignition but it still putters away) since, but that was admittedly only the once. Still seems to get pretty bad mileage for a 1.8L, though she hasn't coughed black chunks out of the exhaust in a while either. No real smoke at the tailpipe now, though once I let it idle for a good 20 minutes, and about 10 mins in, started to smoke up. No unburnt fuel smell in the smoke, but a kind of acrid/bitter kind of exhaust smell. Seems to smell appropriate for a banger with 420,000km? No idea, I try not to sniff exhaust whenever I can.

I thought maybe blow-by was upping pressure and running crankcase fumes through the breather (though the carby intake is pretty blackened... no real silver or brass sheen to be seen), but then wouldn't I get oil that smelled like fuel? Oil smelled fine when I drained it for the rear main seal (oh my god you should have seen the bellhousing xD). And if there's no smoke out the back at load or when idling correctly, then where's that fuel going? Not a spot of fuel under the car either, just that one fecking drip of sump oil from the BRAND NEW sump pan seal.

Power-wise, it's a 1.8L van, you kinda get what you brought... but I would have expected just a little more torque for slight hills etc. in 5th gear. Higher RPM seems to have an ok pick-up-and-go, but low end is soft, forced a downshift to 4th several times today trying to keep 100km/h up a hill.

Sticky carb? Sticky EGR? Stuck PCV? Broken BVSV? Any ideas on where to focus my efforts?

Where is the pcv valve?

I don't actually know! This is all I have to go by https://imgur.com/a/LUXNG

Also FYI, turns out the idle problem is probably the same set of issues I've been working on over on this thread http://www.toyotavantech.com/forum/s...o-manual-choke

I have an EFI model so anything dealing with carbs are completely foreign to me.

Hey M87

If you have a 4y engine here is a blow up with the location of the part. Turns out my rough idle was from a spark plug that was half the correct gap. So next time I have to change them I will buying a gapper to check to make sure the gap is correct.

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