Delica Canada | Mitsubishi Van Club

Diesel engines do not have an air fuel ratio, under ideal conditions they will burn all the fuel until the level of fuel exceeds available air. Then they spit out sooty smoke, they do that anyway because conditions are often not ideal. The wastegate vents exhaust gasses around the turbo when the pressure on the diaphragm overcomes the spring and pushes the rod down. By adjusting the rod you are adding preload to that spring so it takes more pressure before the wastegate begins to open.

More power is a direct result of higher limits on the turbo boost, you can also increase power by increasing the fuel at any given part of the injector pumps range by adding fuel there too, as long as there is air to burn it. For example you can increase the bottom end fuelling for more grunt off of idle, which also makes the turbo spin sooner, or add fuel over the turbo range, or make the fuel compensator more sensitive over that range, if the IP is similar to the others I'm used to. I havent opened mine as I I havent felt the need, or I'm too afraid :D

Generally injector pumps have a wide range of output as they get fitted to various engines, so in short, increased psi should simply equal more power, without worrying about fuelling.

Interesting. So what would you guys suggest I do? Here's my current setup:

-Just put in an K&N Filter
-Have boost/EGT gauges
-Just adjusted the nut on the wastegate, now the boost is maxing at 10psi.

Should I leave the wastegate setting and adjust the setting for some more fuel at the IP? Also what are the max Exhaust Temps that you guys get to?

My rule of thumb is for extended amounts of time don't go over 1000 but short burst its OK to touch 1100

Dustin

remember that in addition to the wastegate both the l300 and l400 have an additional pressure release valve as a safety backup. If you are planning on boosting above ~15psi you have to disable that as well. On the l400 it is a mushroomy looking thing near the back of the engine, the quick aussie fix is to zap strap it all to hell so it can't open.

I'd like to set the boost at 11.5 - 12 psi. Nothing crazy. When increasing the fuel flow, is there a way to know if you're running too rich or have to much un-burnt fuel? Is that when the black smoke starts showing? Is there cause to worry about running rich on Diesels?

Yes running too rich in a diesel tends to cause EGTs to go through the roof. It is lean that is safe on a diesel (unlike gassers). So if you are going to start playing with adjusting fuel delivery you should have a pyrometer installed to be safe.

When adjusting the fuel you can adjust the overall fueling (more of less fuel at all times) and/or you can also adjust the fuel ramp (amount and/or rate of increase in fueling related to increasing boost) within the boost compensator. I haven't seen anyone on this forum talk about tweaking the boost compensator ramp up but it was pretty popular on the Hilux Surfs before they went all electronic.