Injector discussion no fighting allowed!

[NVW]

It can run smoother at a more retarded injection and combustion which is what happens when it pops early or doesnt atomize correctly. The less advanced the less force against the piston.

As far as the minimized risk, there is less noticeable issues when you dont stress the truck, however the main concern of pitting the pistons and scratching the cylinder walls still exists. Thats because if it dribbles when off or just doesnt combust and get pushed out or dribbles just a little after shutdown the fuel will clean the lubrication off the cylinder walls. This could lead to more blowby I suppose as a notibeable indication it has been happening.

Dont worry about overworking the IP, thats a myth. The IP is capable of pushing 4000psi at idle rpm if it had to. So popping off at 2200psi is nothing it would stress over. Additionally at higher RPM line pressure it squirts fuel at 10,000psi, so again 2200psi pop isnt hurting it. What I meant by the IP is working easier is you dont hear as much ticking/clatter from it popping as high. If you arent in the pursuit of power and dont use the truck for power then a low pop pressure could make it run quietter/smoother. Too low of pop might be how injectors are getting burned/scarred when we use these high fuel output PCMs and injection has to work against the pressure of the cylinder compression at high boost.

Definately something that should be common preventitive maintenance. IMO, 100,000 maybe if only a daily driver, 50,000 if you tow often or have performance PCM and have a heavy foot a lot.

Doesn't make sense to me

I think you mean there is less diesel clatter, that can be but bad injectors are injecting at different times so there is an uneven idle.

 

[buddy]

Sorry I meant you get later combustion because its poorly atomized, and at idle rpms it isnt going to push high pressures to improve atomization. At idle it probably just pushes line pressure just over pop pressure. And if you ve seen how some injectors work at just pop pressure they can just spill out.

It doesnt matter when its injected, it matters when ignition and combustion happen. Injection is only related to that.

 

[Turbine Doc]

This raises and interesting question:

Where did the 100,000 mile change interval come from?

I can't find anything in the schedule in my 98's factory service manual about injector changes.

Is 100,000 just a number someone threw out one day, or is it documented somewhere from GM/Bosch/Stanadyne?

100K is sort of a 6.5 site/s passed down site to site rule of thumb based on recommendations from those who have removed and pop tested in the past, not a hard requirement, possibly with advent of ULSD that may need revising some especially if not running a lubricity additive. Bill Heath is a proponent of the 100K recommendation.

 

[great white]

100K is sort of a 6.5 site/s passed down site to site rule of thumb based on recommendations from those who have removed and pop tested in the past, not a hard requirement, possibly with advent of ULSD that may need revising some especially if not running a lubricity additive. Bill Heath is a proponent of the 100K recommendation.

Gotcha.

100k worth of "pops" is quite a few!

):h

 

[dangerousdave]

Thanx, this is one of the best threads I've read in a long time...
and now am subscribed to.

Ya sure, I'm gonna HAVE to change mine soon...last year would have been better.