IP upgrades

[Downhillnz]

So I think I've done as much tuning to my pump as I can. Ive upped the max fuel and I have played with the boost compensator...

Is there anything else I can do? Can I bolt on a 3.1 pump and tweak it? Or is there any other known pump that works?

[geeves]

there is an adjuster inside under the boost compensator that can do magic things but dont know more. Also a long time ago someone suggested heavier springs inside the injectors. Once again I have no more info

[isuzurob]

i talked to mate at turbo and diesel when i built my truck, can machine out the pump and fit a 10mm plunger from memory they have a 8mm standard, a factory pump can pump alot of diesel though, my truck ran 18psi and still black smoke etc, 3.1 pump wont work as they arnt direct injection like the 4jb1 pump and doesnt make enough pressure

[geeves]

I thought you said a while ago you were using a 3.1 pump?

[isuzurob]

ive only used 2.8 pumps on 2.8 and 3.1 pump on my swb 69 i have, i started to modify the internals in my 2.8 pump for my bighorn, but old pump was enough on 18psi then i sold the truck, now modifing a td42 pump with a 12mm head, as i said on 18psi and all the mods my truck had the pump could still pump enough fuel for thick black smoke when i was tuning it

[geeves]

Its not nessecsarily the amount of fuel that gives power. If you could of got the same amount of fuel into the cylinder in half the time (at the right time) through a nozel 2/3 the size into a fine enough mist it would of burnt that same amount of fuel cleanly and had nothing but power. Very hard to do that that with a mechanical pump

[isuzurob]

yes my bighorn had modified injectors and pressure was higher in pump, was played with mate at turbo and diesel, it went very well for a 3 tonne truck, better than my modified 3.1 swb bighorn

[Downhillnz]

I've played with the spring in the compensator.

Would having a lift pump to get the diesel to the pump without it having to vacuum it help?

[geeves]

Only if there is another problem in the fuel system

[jellis]

i found this a while ago while searching for info / mods to the fuel pump.

i have not brought anything from them so have no idea about the company.


http://www.rocken-tech.com/Pumps.html

[Roderunner]

I've played with the spring in the compensator.

Would having a lift pump to get the diesel to the pump without it having to vacuum it help?

I would say yes, pumping the fuel to the injector pump from the tank helps to keep air out of the fuel system, most fuel lines suck some air from the connections/filter fittings/priming plunger. The pump should be mounted as close to the tank as possible.
The injection advance mechanism inside the injection pump is activated by the dynamic fuel pressure . When running at full throttle the pump pressure can drop if sufficient fuel isn't always available at the pump inlet ( in addition to any entrained air bubbles), which can retard the injection timing a tad just when you need it the most.
The injection pumps fuel pressure regulator valve works against the interior pump pressure along with a coil spring (not atmospheric pressure), so if you pressurize the fuel pump supply the fuel pressure regulator valve gets tricked into supplying a higher pressure into the plunger feed orifice, and the higher fuel pressure will also advance the injection timing. Obviously any added on fuel pump should only operate when the engine is running in case of an accident. The o-ring seal on the throttle shaft (among other seals) can leak when the pump pressure is increased if the seals are past their use by date, luckily most of them are cheap to buy so some can be replaced by the confident home mechanic.
Have you rotated the diaphram in the boost compensator?