Both of those seem possible... Wouldn't I also see pretty high fuel trims though?

I think so. You would've seen the same with low fuel pressure. I would focus on the spark by removing one igniter at a time and testing visually with a spare plug.

Today I learned that fuel system cleaner has a purpose and is effective at that purpose. Oh wait, wrong thread. :bonk:

Anyway, put some high strength Techron in the tank, started it, and misfire was gone before I finished pumping up the tires. Still has an occasional miss, but it's so much better now that I am 99% sure it was something in the fuel lines or injectors. If the occasional miss sticks around I know where to look.

Now I need to deal with the whole 2 months without moving set of problems like that new clunk sound coming from the back...

Ok... Update for anyone who cares:

Misfire is still occuring, but MUCH less often, and it's now up in the 2-2.5krpm region only under increasing load conditions (any time you begin to accelerate). Interesting point is now it only throws a code on cylinder 5, which is an improvement from both 5 and 6. I also am pretty sure I heard a detonation one time at high load going up a hill. This all seems to be evidence of an injector/clogging issue, though it's more of a PITA to get at the injectors than the spark plugs believe it or not. Friggin sound deadening plates...

Anyway, I'm going to run another tankful of new gas with injector cleaner through it and see if that resolves the issue. If that doesn't work, maybe get an injector tester? If it is working electronically, Idk how to deal with a clogged injector yet. Might be a replace kind of deal?

I'm no expert but I've opened up some nasty rails. Consider gravity and that the failing ones are at the rear. If it was mine, I'd crack it all open to inspect. I might have wasted my time but I'd feel better knowing. Maybe a couple junkyard injectors... taken from the front? ;)


I get that it's a PITA :(

So you think the rail itself might have gunk in it (too)? Didn't think about that... I suppose it's not much more work than it is to just get at the injector itself. If it's got gunk, clean out the rails and get new injector for the rear? If the rails are clean, I suppose I still need to get a new injector...

Maybe not the rails but the shit would definitely tend to settle at the low point. No idea how much there is. Maybe just more injector cleaner but I've never trusted it. Maybe it just broke loose more shit from upstream.

Not entirely rational but, if I already kind of had to go that direction, I'd check it.

Pulled fuel injectors to test them. Broke an o ring. This might sound like a stupid question, but what is the best way to order the right orings to replace them with? My Google fu is weak today. Denso 711DC is printed on them.

Edit: Nevermind. I'm a dumbass. You CAN look that up as a vehicle-specific part, but at multiple dollars an o ring that seems like a ripoff.

This place seems to think a generic size for these is 7.8x1.9mm which seems about right...
https://theinjectorshop.com/products...-bulk-pack-100

Probably ok but, as long as you have them out, just take one to an auto parts store.

"What?" you say. "Brick and mortar? Ok, boomer."

Well, that should have been the obvious solution... Yeah I'll bring it next time I go. The problem with that is the local store doesn't usually stock useful stuff like that. Really missing that big regional NAPA near where I used to work.

I was actually just at the auto parts store earlier today to pick up stuff.

Regional NAPA warehouse is right across the river from me in Portland. There are closer places but it's often worth the trip. I got to know a couple of the guys there on a first name basis a few years ago. The shit-talking was fun.

Well, I found A problem... Not sure if it is THE problem. One of the fuel rail pulsation dampers is missing the adjustment screw.

In other news, all the injectors seem to be working fine under low pressure at least. Ran some carburetor cleaner through them while pulsing and noticed no difference between them. Microfilters on the inside looked intact and clear too. Might swap them around when I put it back together just in case I still have the problems. At least then I'll isolate it to a specific injector or something else on cylinder 5.

Edit:. Debating whether to get a right side fuel rail for ~$80 (in addition to damper for ~80) because of all the rust. I got it cleaned up a bit but needing a chisel to remove some of the rust isn't confidence inspiring when looking at a pressurized fuel tube that goes next to the engine...

Interesting! I was not aware of the dampers with those limit screws. Some googling confirms correlation with your symptoms. I think you may have found it. *knocks on wooden coffee table*


for instance... https://legacygt.com/forums/showthre...1924.html?amp;

Lol I did find that in my research into 'wtf are these things called'. Hopefully I can have this finished by next weekend. Need to bring the other automatic car in for some warranty work and there will be hell to pay if we don't have a working car my wife can drive...