swampedout

1980, 20r.

Cylinder 1-4, dry: 170, 160, 160, 160.
1-4, wet: 180, 175, 170, 175.
This was done with the autozone loaner tool so I cant vouch for the numbers themselves. I didn't get a lot of oil in the cylinders for the wet test because I had to jerry rig a system to get it down there. Cylinder three has mildly stripped plug threads. I put fresh plugs in and drove them for a day and pulled them to do the test and the tips were already pretty black. No pics...

This engine is new to me, supposedly "rebuilt" in the past five years but in almost every single way this vehicle has not been upkept. I've been redoing the wires because a lot of electrical components haven't been working properly. I was adding a ground direct to the engine because there hasn't been one and the starter seemed like it was having trouble turning the engine over. At some point while I was going through this stuff the other day, the car would crank and run really rough for five to ten seconds and sputter and die like it wasn't getting fuel. I got worried and pulled the spark plugs to replace them and figured that while I'm at it I might as well check compression.

It's got an aftermarket fuel pump inline and it looks like garbage to me but I haven't sourced a new one yet. Also haven't hooked up fuel pressure gauge or checked timing. But since I put in new plugs and plug wires and better grounds I've been getting it to fire up pretty easily. The idle is smoother but still shakes a bit. No major tapping (compared to my other yotas). Oh and it's got an exhaust leak from some port I don't know the name of directly below spark plug 4.

As much as I hate myself for being so enamored with this rusty money pit, I keep thinking about the day when I will have it where I want to be. A guy two hours from me is selling off his 80s yota collection and I'm thinking about picking up a 20r from him on my next day off. I dont need to swap in a new engine yet, but the deal is enticing and I see a rebuild in my near future.

So I guess my big question is: how bad/good are these numbers and how soon should I be thinking about getting elbow deep in some engine work (based off the very limited information I've provided)? I have limited experience working on engines.

millball

Compression is near perfect, no problem there. Might be some carb issues if plugs black.

What is oil consumption?? What is fuel mileage??

swampedout

Ive only been doing short city trips so its been hard to monitor fuel. I just filled it all the way up from E so in a week I should be able to estimate. Its not a gas hog though.
Ill check oil tonight. I changed it abt a month ago. The stuff that was in there was very dark. Ran some seafoam thru prior to change.
I hear these aisin carbs are difficult to adjust but im learning where to start

ToyOkie78

Like Millball said compression is good, my 82 22r has over 300,000 on the short block & the head was cheaply gone through right before I bought it. My compression is 135-140ish

Black on the new plugs- were they dry & black or damp & black?

Dry = your running rich obviously, but could be due to weak spark also. Do the plugs spark nice & blue or more orange?
Damp= likey oil getting on the plugs

How did the old plugs look?

On that #3 plug that's slightly stripped just put extra antiseeze on it and gently snug her down, my #4 is the same way

I run a cheap 12v Mr gasket low pressure fuel pump, just just a good regulator. So long as your pump isn't the pulsing square mega cheap one you'll be fine until you upgrade later on

My biggest thing is get the port below #4 exhuast plugged up somehow. I don't care if every 6 months you jb weld it lol. If you don't in your future you'll have exhuast valve issues on that cylinder from it cooling rapidly when you shut it off while thst exhuast valve is hot

swampedout

The plugs are dry. The old ones were very black but also dry.

The exhaust port has a hose running into or around the back of the engine. Ill look at my fsm to figure out what it is.

Havent checked the spark yet. This is one of three projects im working on in my time off.

swampedout

So the hole blowing out air under cylinder 4 connects to a hose that runs around the back of the engine into the carb. Anyone know what this is called so i can replace it?

Thanks

ToyOkie78

Most people refer to it as either egr tube or egr fresh air tube. It has another technical name I'm trying to look back up

(Edit) I believe it technical name is " Air Injection Manifold " on later fuel injected models referred to as "pulse" air injection manifold

swampedout

Thanks. Got it plugged for now. I can actually hear the engine for once

swampedout

I think im running rich. Plugs seem dry. Also black build up at end of muffler.

What regulator do you recomend? And how can i measure pressure to know im within spec?

Thanks. Ive been driving this thing for two weeks while i work on my t100. Shes slow and steady but im Taking her into the mountains this fall so i gotta start tuning