1hz miss

[Yukontoyota]

I've got a 1hz in my 92 4runner, I think it's around a 2008 year, when I got it, it had a miss on 6 and 4, would fuel knock like crazy and smoke blue at idle and lots of black smoke if you stepped on it but no blow by at all. I took the head off thinking something was messed up but it wasn't. Head vacuum tested fine, was flat, pistons looked fine, cylinders looked fine. I set valve clearance when I put back on. I figured it was the injection pump and when I took it apart the timer had a snap ring for a shim and some other silly things. I rebuilt it with all new internals, except shaft and got a new housing. It does the same thing but only on number 4. If I open the injector line the smoke goes away and so does the fuel knock. Anyone have any ideas cuz apart from taking a piston out to see if it's got a broken ring or something I'm stumped. New parts include all injectors, all internals on injection pump except some governer parts, head gasket, head bolts, timing belt, precups on 4 and 6.

 

[Rigster]

I just had to say - kudos on shoehorning that 1HZ into your 4 runner!

Did you compression test the cylinders? If the compression is all good, I would not be too concerned about piston rings.

Have you tried testing/moving the injectors? IE: swap cylinder 4 injector with another cylinder and see if the problem follows the injector? A fouled/worn injector can cause this as well.

 

[Themcfarland]

If you have not, try swapping injectors
I would also just do a compression test over pulling it apart again, like Rigster said.
I feel with the stuff you have already done and the smoke going away when you pull that line, it is either the injector or the pump port .