more power

[andrewward0377]

hi I want more power from my engine 4jb1 2.8TD, I have located the fuel adjustment screw on the fuel pump this has a lock nut, to loosen nut clockwise or anti clockwise ?,what tools do I use 13mm socket wrench ? spanner, how many turns on the screw for maximum boost, how do I control idle speed ?
what else can I do for max power from the engine, thanks

[RamstadTech]

Hi

A forum and a google search would give you an good introduction to what to do.
Here is a link to the tread I think got the most detailed explaination in how to increase the fuel:
viewtopic.php?f=19&t=629&p=5083#p5083

From what I have read here is the things to do:
-More fuel: Will increase power, but also exhaust temperature
-More turbopressure: Will increase power, but not necassarily exhaust temperature cause air is the cooling factor in a diesel engine. But you need exhaust gasses to build turbo pressure so it will take some time to reach the top pressure.
-Bigger exhaust: Will help the turbo to spin up at lower rpm. As mention in the previus point the turbo need exhaust gasses to spin. The lower pressure the turbo have on it's outlet the more pressure is going into the turbo's shaft to push the inlet air.
-Perfect injection timing: Most power is achieved from each explotion when the fuel is injected at correct moment. To find the best timing the adjustment should be done on a dyno while monitoring exhaust temperature and listening for pre-ignition knocking.
-Intercooler. The colder air the more air mass per litre. Also, cold air will help help cooling the engine/exhaust gases.


I do not have any experiance with diesel tuning. This is just a resume of what I have red about 4JB1-T tuning.
Could someone tell if the things I have written is correct?

Also I have some question about 4JB1T tuning. How big does the exhaust have to be? Is 2,5" enough? How important is it that it is 2,5" all the way from the turbo? Is it enough to make 2,5" from the first flange?

[jellis]

as far as i understand if you make an exhaust from the first flange there gains arent as impressive because the dump pipe is still restrictive.

[geeves]

Im running 2.5 inch from first flange and the gains over the original exhaust were impressive Also fitting a snorkel gave a noticeable gain but the bighorn intake is more restrictive than the Mu so you would get less. After doing the pump seals it had to be retimed by ear by the mechanic and it became a monster compared to what it had been. No dyno or EGT figures sorry

[andrewward0377]

I have turned the screw a full turn the engine revved at 2000, adjusted idle to its minimum setting, revs went down to 1500, turned the screw out 1/4 , revs 1200 still too high, turned screw 1/8 but could not adjust idle as it was to its limits, turned screw again a fraction idle came to 900 but encountered a problem with idle as pressing on the gas pedal the revs where going up and down to 1500 to about 500 when releasing gas pedal, what is the cause of this ?