GU 4.2TD fuel troubles/boost compensator - DEISEL EXPERTS?

[GQ4.8coilcab]

Hey guys,
Having a bit of drams with my td42t atm, Heres the story.
Put the patrol on the dyno before my big kimberlys trip just to check all temps. Last year after the hi flow turbo and big intercooler it made 120rwk with temps around 470-480 post turbo and 14pounds of boost. Ran it up on the dyno the other day it made 85kw. Played with the fuel pump but still struggled to get fuel into the engine temps around 280 and fuel pumped maxed out and only12psi boost (i assume no heat couldnt get the boost). Jumped to conclucsion and thought it was the fuel pump. took the fuel pump off and injectors. Injectors fuarkked (opening at 90psi should be 130 apprently) and fuel pump spot on. Put it all back together ran it up on the dyno made 100kw after we played with the pump and temps still only 350 post turbo..... We pulled the boost compensator tube off and ran it up with no boost to the compensator. Did not make a difference at all. We then put 18psi to the compenstator with a reg and still no more heat. Could it be the boost compensator. I havent done the tappets, could it pick up 20kw? Im doing tappets tomorrow but any suggestions. Im going away on thursdays so would really like to get this sorted.
Thanks Julian

[GQ4.8coilcab]

Forgot to add we adjusted the screw ontop of the compensator and it made minimal difference either way we move it

[Northside 4x4]

If the injectors were opening at 90psi you wouldnt have a running engine
105-110Bar is optimum pressure opening range. About 1650psi.
130 is to much and will screw with pump timing alot, so unless you account for it, it will give a performance decrease.

It will be the stainless mesh filter on the inlet banjo that is likely to cause the problems you describe. Or even a blocked fuel filter.
If the pump cannot draw the fuel in, regardless of what the fuel screw or compensator is doing, you wont have optimum fuel output.

[GQ4.8coilcab]

If the injectors were opening at 90psi you wouldnt have a running engine
105-110Bar is optimum pressure opening range. About 1650psi.
130 is to much and will screw with pump timing alot, so unless you account for it, it will give a performance decrease.

It will be the stainless mesh filter on the inlet banjo that is likely to cause the problems you describe. Or even a blocked fuel filter.
If the pump cannot draw the fuel in, regardless of what the fuel screw or compensator is doing, you wont have optimum fuel output.

sorry 90bar... the diesel bloke set it to 140 as he said it will bed into 130. Could he have set it too much you reckon? I took the banjo fitting off and cleaned the little gauze thing all good. Changed the fuel filter 2000kms ago but to be safe im going to put another one on now. Have you ever heard of boost compensators failing? If i took the boost pipe off too it shouldnt it have decreased fuel supply. It did nothing on or putting 18psi to it.

[GQ4.8coilcab]

any suggestion on what i should advance it to. I didnt check pump timing i just scribed it and put it back on the mark, so its at factory timing atm

[Northside 4x4]

If the injectors were opening at 90psi you wouldnt have a running engine
105-110Bar is optimum pressure opening range. About 1650psi.
130 is to much and will screw with pump timing alot, so unless you account for it, it will give a performance decrease.

It will be the stainless mesh filter on the inlet banjo that is likely to cause the problems you describe. Or even a blocked fuel filter.
If the pump cannot draw the fuel in, regardless of what the fuel screw or compensator is doing, you wont have optimum fuel output.

sorry 90bar... the diesel bloke set it to 140 as he said it will bed into 130. Could he have set it too much you reckon? I took the banjo fitting off and cleaned the little gauze thing all good. Changed the fuel filter 2000kms ago but to be safe im going to put another one on now. Have you ever heard of boost compensators failing? If i took the boost pipe off too it shouldnt it have decreased fuel supply. It did nothing on or putting 18psi to it.

It takes a very long time for the pressures to drop 10bar. Normally cars with around 80-90K on them will be at about 100-105bar still from a factory set 110bar...

Im not sure why it is set at 140, and that is probably why there are problems with it now. The higher the pressure is, the further around the pump cam must go to deliver said pressure, decreasing actual injection time.

Ive never heard of a compensator failing as there is just really nothing thats working hard enough to fail.

[GQ4.8coilcab]

The higher the pressure is, the further around the pump cam must go to deliver said pressure, decreasing actual injection time.

Ive never heard of a compensator failing as there is just really nothing thats working hard enough to fail.

Yeah i was thinking that, Ill ring the bloke up tomorrow and ask him what he set them at. Really appreciate your advice

[Northside 4x4]

Also I like your signature

Also like a dollar for everybody that goes, hmm ctrl+W (tries it) GODDAMMIT!

[GQ4.8coilcab]

Also I like your signature

Also like a dollar for everybody that goes, hmm ctrl+W (tries it) GODDAMMIT!

haha i really should change it, i want people to look at this thread not close it

Well im advancing the pump to .84 the diesel bloke said. See how this goes

[GQ4.8coilcab]

Pump was out a touch.... advanced it to .78 got temps up to 400, making 100kw didnt matter how much fuel we put it same thing couldnt get any more heat into. So we backed the fuel off making 100kw which is enough for the trip and when i get back might advance it to .82 or something.