08 GU over fuelling issue?

[Shonky]

Hi guys Shonky here,

About 2 months ago, I did Theo's first major service since buying it, (Radiator and intercooler taken off and flushed, new engine oil, coolant, oil filter and fuel filter) and have noticed a major increase in my boost (was quite sluggish for a while) as well as keeping much cooler (was overheating with the slightest hill).

So far so good but now I've noticed that he's using up a bucket load of fuel. I'm talking about 20L+/100km on the flats at 100km/h.

The only issue that I'm aware of is that theres a crack in the inlet hose to the turbo which will be replaced on Friday.
A friend suggested my MAF sensor is blocked but I gave it a quick clean with CO Spray during the service.

Any other suggestions to determine the "overfuelling" issue would be a great hand.

Shonky

p.s. I'm a Second year heavy vehicle mechanic who only really got into the 4wd scene about the same time I started so be prepared for a mountain of questions if I lack the understanding. Thanks

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[BigRAWesty]

I'm guessing its a diesel..

A simple first test would be to check the fuel return line. Simple remove rear carpet and pull up inspection hatch for the tank.
Remove the small hose and get someone to turn it over for you, if you have a fuel come out its fine...
Move onto injectors..

Kallen Westbrook
Owner of
Westy's Accessories

[threedogs]

check all vaccum hoses and IC hoses for splits, dislodgement or just loose.
just re read post, clean the MAF, spray avail at super cheap, to much boost may see it go into limp/ over boost.
No or low boost will see it over fueling, are you sure all vacuume lines are correct.
Might need to NAD your ride to Manually control boost. might want to block egr while your Nadding

[Shonky]

Cheers Kalan,
Ill get on checking it over the next few days. What would be involved in checking the injectors?

[BigRAWesty]

Cheers Kalan,
Ill get on checking it over the next few days. What would be involved in checking the injectors?

I'm not 100% sure, I'd say take it to the professionals... But that's your line of work so I'd be asking some of your work mates.
They usually test 'cracking' pressure. If the injector has failed it would be allowing fuel threw all the time..

Any excessive smoke coming out while driving?

Kallen Westbrook
Owner of
Westy's Accessories

[Gu01patrol]

If all else fails, I would recommend also having yr turbo checked, i was having a simular problem with hi temps and hi fuel consumption, so i replaced the water/oil cooled (Garrett), with just an oil cooled one (Garrett), temps dropped by 20deg, and fuel consumption back down to around 10L/100k's average. the orignal turbo had done arond 240K's


No expert just a thought worth while checking

[Shonky]

Thanks guys for your advice. Turns out that the solenoid for the EGR valve was faulty which allowed the valve to stay open, eventually overheating the engine ( blocked the valve off now, all sorted :-) ) and I had a hairline cut along the intercooler intake hose so now with that sorted out, I'm getting just under 12L/100km highway miles