Diesel Injection Pressure

[4x4fun]

What happens if i crank up the pressure of the injectors by tightening in the bolt on the injectors under the top? Will it just break the injector pump? Is there any benefit?

[steveNZ]

as far is i know injectors can only be ajusted in the workshop with correct pressure testing kit. think trying this your self will just lead to injectors all having diffrent pressure and ive not heard of upping injector pressure having any benifits
uping the pump delivary a bit will produce more power

[4x4fun]

What problems can happen if they have different pressures? Does anyone have a spare 4jb1 injector ive got a broken one

[steveNZ]

uneven running if there set at diffrent pressure and im shure you will also have smoke problems if you start messing with them cant realy see the point of messing with the injectors like i said turning up the injector pump and booosting the turbo will produce more power
i do have a coimpleat set of spare injectors not realy sure if i want to part with one think im going to get the hole set reconditiod in future

[4x4fun]

Wel id be interested in buying the set off you

[steveNZ]

Theres a number on the side of your injectors get it to me ill see if they are the same

[geeves]

A long time ago someone did suggest increasing the spring pressure inside the injector which has the effect of making the injector open for less time but put in the same amount of fuel. Apparently this is a good way to more power but I dont understand the science or mechanics of the injector so dont know for sure. It might work but it might also do bad things.
Your on your own on this one but do publish the results

[steveNZ]

Good info alan id not heard of that before
Have just pulled one of my spares out of old engine looks like they have been reconditiond so if your intrested ill swap them with the ones in my truck and sell you them
injector no is 844 48-2030 C

[steveNZ]

Might be worth you looking around local breakers first see what there asking for a set by the time you add in posting and enougth to make it worth while

[4x4fun]

Will have a look tomorrow. Its my fault i broke one when i dismantled one of them the part the rests against the spring came out and is now lost forever :O the others appear clean and working. I did crank up the pressure by half a turn on each in hopes that the higher pressures atomize the fuel better and have less smoke and more power, well thats my theory anyway lol

[steveNZ]

will be intresting to see how you get on boath with finding new injector and with the smoke
let me know if you have problems and still need a set am a bit reluctant to let them go but if your realy stuck im sure we can work something out

[wbski007]

All injector work should be done at a qualifide diesel shop, unless you really know what your doing, I've taken them out and cleaned them but that's about it. Best to leave the stock ones alone and just go with adjusting the pump for more fuel unless your really getting into big time racing the stock injectors will do fine.

[4x4fun]

Ive got another injector and put it together, only very small amount of black smoke at 4k revs when revd. much better than before when it had white smoke on idle lol Its easy rebuilding injectors as long as you are delicate and have mechanical knowledge and dont lose the damn parts like i did.

[steveNZ]

Glad to here here you got it sorted keep us posted on how the smoke goes as i have the same problem of smoke when idling

[4x4fun]

runs like new at the moment, i had alot of problems starting when cold to which have now been solved by cleaning and increasing the pressure.

[lotusfrontera]

Injectors should really be set up by a specialist because it is the spray pattern that is req`d from the injector to be opitamised. think the spray pattern is a conical one.In correct setting could lead to heat spots on piston crown and could eventually cause piston damage.

[geeves]

true

[mikehutton]

You need to have the right tools to measure the Diesel Injector pressure accurately, must have some technical knowledge on engines to do this.

[madazrx2]

hey guys can u tell how to increase the fuel pressure on a 4jg2t