The K.I.S.S. principle?

[Island Moose]

I have now heard conclusively from a number of reliable sources (Kianseng Injection Indonesia, Ens Industrial Toyota (mine trucks) in SK and a number of owners on the ToyotaDieselMadness board) regarding the 3B-II engine with the Denso rotary/distributor style pump. All of them report to me that the injector opening pressure for new nozzles should be 145-155kg/cm2 or 2100-2250psi.

This is of course a remarkable bit of information, considering my injectors are currently set at 125kg/cm2 or 1800psi, a difference of 450psi or 20%!!

I suppose the rebuilder used the nozzle part # to find the opening pressure, but this part # must have led back to the 3B engine with the inline pump, not mine. This is understandable given the rare nature of this version.

A weaker spring setting in the injectors would certainly throw the fuel-delivery system into the turmoil that I am experiencing, with too much fuel at the wrong time in the engine's cycle.

In any case, I can get the injectors back up to Nanaimo tomorrow, and hoepfully they can re-set them right away. I'll install them on Thursday and report back to the group. I may have to play with the full load adjusting screw now, given the way it was monkeyed with to stop the smoking.

Let's hope this is the fix.

 

[Island Moose]

BTW, can someone suggest a starting point in re-setting the full load screw/fuel adjustment screw? Mine has a steel band wrapped around it which I assume denotes the maximum setting inward (to protect the heads against too much fuel/heat?)

 

[Island Moose]

Man I hope I'm right with this...or I'll be eating some crow! Action almost refused to do it...saying that all engines are 125bar unless turbocharged. I had to insist, and they finally said something like "we'll set them to whatever you want".

I said it couldn't run any worse than it is, and that three injection mechanics disagree...we shall see.

 

[wesintl]

Here's to hoping that fixes your problem Moose... I'm not sure what i'm going to do online once your saga ends...

 

[waaz]

Hello
When the tech rebuilt your injectors he should have noticed that the size of your shims. 0.0020 = 90 PSI. Your engine being 450 PSI higher = 0.0100 more in the shim. This is just about a 1/8 ", visable to the naked eye. A light should have gone on. Also there is a number on the holder or the nozzel, because there is different nozzels, and from that # they should be able to get the specs. Also did they check your nozzels before they took them apart, they should have noted the crack pressure for every nozzel before and after rebuild. Even if your nozzels were that wore out, that would have put their crack pressures in the neighborhood of the ones of a good one with a inline pump.
A good tech tests and does not assume or guess.
waaz

 

[Island Moose]

Waaz, these are things I wish that I had done at the time. I don't know if the nozzles were tested or whether they just broke them down and figured from the wear and corrosion that they need to go. I know that they used the # off the nozzle to set the pressure at 125 bar, but that same number pulled up 155 bar at another rebuild shop in Saskatoon.

 

[theSherpa]

as long the the injectors are coming out, make damned sure the nozzles are the right part number for the 3B-II (get the number off the installed nozzles and write it down). crack pressures won't mean jack if they aren't. don't trust anyone but yourself with such an off-the-wall configuration (3B-II in NA, that is).

Steve

 

[waaz]

Moose I PM U

 

[Island Moose]

Waaz, the shop you suggested said 125bar, like mine does. I asked him about why the shop in SK would say 155, and he said there are some engines out there that would be that high. Again, nothing certain.