4.2 gu running out of fuel at high boost.

Post by **J.Dixon80** » Sun Sep 20, 2009 11:11 am

hey guys just had my gu tuned up and the highest boost that it would run was about 14psi before it started running out of fuel, still have the standard fuel pump, but thought it would get a bit more out of it. they think if the injectors were cleaned out it would go better, but wanted $750 to do this, i thought this was pretty pricey just to get another 1psi out of it, is there any other ways around this? or should i bring the boost back to say 13psi?

any thoughts or knowledge is much appreciated?

Post by **DR Frankenstine** » Sun Sep 20, 2009 12:49 pm

What makes you think its running out of fuel. It shouldn,t
Try a new fuel filter

Post by **Rhysta** » Sun Sep 20, 2009 5:44 pm

Did they adjust the fuel?

Sorry had to ask..

Post by **Tomo_89** » Sun Sep 20, 2009 5:53 pm

did you wind the fuel up. I've seen stock GU's make 20psi with just fuel and boost. how are you adjusting the boost it could be something to do with your boost controller. Also where are you measuring the pressure from.

Post by **J.Dixon80** » Sun Sep 20, 2009 8:27 pm

yeah as far as i know the fuel was wound up accordingly, and just replaced the fuel filter.

Post by **weeman** » Sun Sep 20, 2009 10:49 pm

are you running a standard turbo or something larger?

I know with standard at 14psi u should have a bit more to play with however your egts will get high as the factory turbo is about at its max efficiency range...

ah with roller turbo my standard pump was maxed out 15psi couldnt get any more fuel....

Post by **PGS 4WD** » Mon Sep 21, 2009 10:19 pm

Mine used to run out of fuel at high boost high power and it was the water separator, mine was a 2.8L before hand and I used the 2.8L fuel filter with water separator on the bottom, It was easy to see on the Dyno as the AF's got leaner and the Pyro dropped dramatically. I fitted the one piece 4.2 filter and had no more issue.

Joel

Post by **mq_camo** » Tue Sep 22, 2009 3:50 am

J.Dixon80 wrote:yeah as far as i know the fuel was wound up accordingly, and just replaced the fuel filter.

hey mate who did you get to tune your car?

Post by **garth** » Tue Sep 22, 2009 10:05 am

J.Dixon80

PostPosted: Sun Sep 20, 2009 8:27 pm
yeah as far as i know the fuel was wound up accordingly, and just replaced the fuel filter.

shouldn't be the pump not delivering fuel,...There's always the filter in the banjo fitting on the pump?...check the simple stuff first.
How were they checking the gate wasn't wasting?

regards

Post by **Dzltec** » Tue Sep 22, 2009 1:23 pm

Maybe what he means is he can't adjust anymore fuel into it because its at its limits. You may have a 10mm head and rotor pump, if so you need to go to an 11 or 12 mm unit.

What sort of power are you making?

Andy

Post by **fumduk3** » Tue Sep 22, 2009 6:28 pm

do you have a boost compensator? rotating the plunger/diaphram to the "more ramped" side will increase your fuel quicker in relation to the rise in boost. i have only turnrd my max fuel screw 1/2 from factory setting not wanting too go any more cos i also like fuel economy. my 4.2tdi would get to 15psi fairly quickly but when cruising along and then putting the foot down boost would go up too max buy not much happened no smoke at all. diaphram was at minimum setting, so i rotated it and now boost comes on even faster, and cruising at 100 and put the foot down only tiny puff and pulls instantly instead of full boost wil nothing happening. dyno tuning i would expect to have a grin on my face from ear 2 ear, sounds like you arent grinning but should be, it should go fantastic.......

Post by **fumduk3** » Tue Sep 22, 2009 6:32 pm

do you have a boost compensator? rotating the plunger/diaphram to the "more ramped" side will increase your fuel quicker in relation to the rise in boost. i have only turnrd my max fuel screw 1/2 from factory setting not wanting too go any more cos i also like fuel economy. my 4.2tdi would get to 15psi fairly quickly but when cruising along and then putting the foot down boost would go up too max buy not much happened no smoke at all. diaphram was at minimum setting, so i rotated it and now boost comes on even faster, and cruising at 100 and put the foot down only tiny puff and pulls instantly instead of full boost wil nothing happening. dyno tuning i would expect to have a grin on my face from ear 2 ear, sounds like you arent grinning but should be, it should go fantastic.......

Post by **fumduk3** » Tue Sep 22, 2009 6:36 pm

oops double posted sorry

Post by **J.Dixon80** » Tue Sep 22, 2009 7:54 pm

still the standard turbo, only making 90 kilowatts from 14.5 psi with 35's though,, after doin all this the clutch is now slipping when i put my foot down in 3rd and 4th so have just dropped it back to 12 untill i get a new tuff clutch, dont really know the full details on this banjo filter and the boost compensator? only sorta know the basics, still learning.

Post by **clm434** » Wed Sep 23, 2009 12:37 pm

Do you have an electric pump to push fuel up to the injector pump? Mine would barely idle at 500 and would max at 1500rpm. Why? Blocked the lift pump. Just fitted a filter before it.

By the way that was at 10psi

Post by **Dzltec** » Wed Sep 23, 2009 8:23 pm

What brand of 35's are you running. What diff ratios? You may be only making 90rwkw because the tyres are sapping 10-20kw out of the driveline.
Post up dyno graphs along with boost and a/f ratios, egt's if they can.

Andy

Outer Limits 4x4 Board

4.2 gu running out of fuel at high boost.

4.2 gu running out of fuel at high boost.

fuel

stuff

stuff

stuff

Who is online