fuel pump mixtures

[muvit madness]

hi i was after some info on fuel pump timing as i installed a jackaroo top mount intercooler & was wandering if anything had to be done to the fuel side of things too improve the performance as i havent noticed any differance after the install?
if anyone can shed some light on this or is it a job for the trusty diesel mech .
thanks in advance.

[Garth]

I wouldn't think there would be any adjustment needed, you obviously already had a turbo and have just added an intercooler. Just check that the pressure line from the turbo / intercooler to the fuel pump is still connected, otherwise the boost compensator part of it won't work. this line has a tendency to come undone or be overlooked when hooking things back up.
Could maybe try tweeking mixture screw up 1/4 turn to improve power but too much not a good thing. Intercooler won't make much difference at low speed (<60kph) as not much airflow over it, but should improve economy and performance when cruising on open road.
To improve cooling around town you could add a 10" electric fan to blow air through it ( I keep thinking about doing this to mine).

[turnturn]

Along the lines of what Garth is saying, I found adding an intercooler (to a 92 4jb1-t) only had a noticeable effect on the open road. I think that is probably worth about half a gear on some longer, higher speed hills and probably improves your fuel economy a little but I didn't do any comparison before and after fitting.
I also am considering fitting and additional fan for lower speed driving.
I think that i also might have lost a little bit of boost by fitting, maybe 0.5 psi.
While I don't regret fitting it, I did not get the improvements that I had hoped for after reading other peoples feedback on intercoolers.

[muvit madness]

ok i geuss i just expected a little more than just lower exhaust temps etc
i allready have a 8" fan top mounted coz it seem to hit the hump on the rocker cover underneath the intercooler.
i too have lost 0.5 of boost but this could be due to the fact that the boost line is situated
in the inlet housing & not in tee piece to turbo.
thanks anyways 4 ur help.

[Jimmu]

The thing with an intercooler is that it does not so much make massive improvement in power in itself but it opens the door to massive improvements in power.

Diesels are largely limited to their power output by their EGT's. Anything that reduces EGT's means you can increase the fuel and boost and thus increase the power.

Wind up your boost and your fuel and you will have a smile on your dial

Jimmy

P.S. I like your rig.

[muvit madness]

hi jimmy thanks
i was just wandering how to wind up da boost
has it got anything to do with winding in the waste gate
as im unsure how to get more outta her?
on the other hand i took the mu to west end diesel services
the other day & told them about the loss in performance
(mu that is ) he test drove it then disconnected the
air pressure line that runs from the egr/pollution mess
to the rear of fuel pump diaphram (i think). & connected it straight to
were the boost line was connected to i/c inlet pipe.
boy that put a smile on me dial what a differance that made.
then he told me that my pump wasnt getting enough fuel pressure.
definately recomend doing this if you havent experienced the gains
that others have just my 2c.
also ive picked up 0.5psi that was lost b4 i/c was installed.

[Jimmu]

You need to fit an inline boost controller in the pressure line between the turbo and the wastegate. They vary in how they work. Cheap ones bleed off air, good ones actually block airflow until desired pressure is achieved which improves how fast peak boost is reached. Either way they trick the wastegate into thinking that it has not reached full boost keeps full exhaust gasses going through the turbo longer producing more boost. Either that or fit a higher pressure waste gate actuator to achieve this.

You then need to fit a boost gauge and simply wind up the boost to where you want it.

More boost + More Fuel = More Heat and More Power.

How much heat is too much heat seems to be somewhat debated when it comes to the 4JB1T.

Jimmy

[muvit madness]

cool thanks jimmy
i'll purchase one with next weeks pay & i'll let you know how it all goes.
what would be a safe psi to goto if im boosten around 11psi?.
also should i do a minor fuel flow adjustment to accomadate any extra
boost? just worried about leaning out motor & detonation .
cant afford v6 converion just yet until my sas is in, in march (07)

[Jimmu]

A diesel does not suffer from lean out the way a petrol does.

By virtue of the way a diesel runs you cannot run it too lean. Not in the traditional ie 'petrol' sense anyway.

Jimmy

[geeves]

A diesel will accept all the air you can give it. ie 20psi on its own wont do any harm. Problem is it wont give you much more power either as the amount of fuel will be the same except for any extra allowed by the aneroid compensater in the fuel pump. This make little differance at high boost though.To get round this you tweak the mixture and big power can be made but it comes at a price. If you use this extra fuel it makes more heat and can cook things ie head turbo etc. A large exhaust helps but every change for more power will reduce reliability.
14 psi doesnt seem to hurt A lot of people are running higher than this with no bad effects but a few people have melted there turvbos as well.

[muvit madness]

hi jimmy & alan
just thought i'd give you a update, i went to rocket ind & purchased a g.f.b boost controller & installed it last sat. this paticular one uses a 3mm allen key in the top to adjust bleed off. so i wound it out about 10 turns or so & went for a drive i was stoked unimaginably to see the boost gauge read 18psi & the turbo spooling up sounded awsome as well. so i pulled over & began winding back the grub screw a couple of turns at a time. repeating this process 5 times until i got it to 14psi. i decided on that poundage until i make & install my 2.5" exhaust system from dump pipe back then i'll give the mu to westend diesel services to run on the dyno & tinker accordingly for max boost etc...but i,ve noticed the differance in power gains now that more air is being foced down her throat?