gu 4.2 turbo problem

[teza04]

has anyone else had issues regarding their turbos , not sure if i have a problem but when towing my 2 ton van up any decline the patrol power just dies a slow death, some declines lucky to get above 60kph , and while powering up the hill if i release the acc and put my foot back down i can hear the turbo spinning as if it is in neuatral and not giving any extra power, do i need a new turbo or is there a way to test them. thankful to any replys on this problem

[slingshot]

Where are you based? Just had my(2.8) turbo tested last week, just google a turbo mob near you, they should be able to hook up a boost gauge& take the beast for a spin.

[MudRunnerTD]

when you write Decline i am assuming you mean Up Hill? Incline is up hill and Decline is Down hill? All good.

It actually sounds to me like you may have a Clutch Issue for it to free spin on re-acceleration uphill towing a load??

Can you feel your clutch spinning?

When you are chugging up the hill towing the load and cant get to 60kmh what gear are you in? what are the revs like?

[teza04]

yep sorry about that i meant incline, only just had the clutch replaced 2 weeks ago, if i am starting off at the bottom of a hill towing a caravan lucky to get upto 60kph in third at about 3000rpm, then had to drop back to second to stay a constant 40-45kph at about 2500rpm, towing on the flat roads lucky to get over 100kph and a freind towing a heavier van with the same model patrol but a 3ltr turbo catches me in no time.

[teza04]

we are on holidays at the moment and near ballarat, can anyone recommend a good place to get it tested
thanks

[MudRunnerTD]

Sounds like you should put it on a Dyno mate, that will sort out what is happening and may even find some hidden KWatts ;)

[teza04]

thanks for that will do when we get t ballarat

[nissannewby]

If she is standard mate they are like that. As mudrunner said a nice tune at about 12psi with correct fueling should see you smiling from ear to ear

[Dingo55]

Hi teza, hope there's nothing big wrong with your 4.2. Keen to hear how things go, so please post an update when you can. There uesed to be a 4x4 dyno guy at Big Country 4x4 Accessories, 204 Creswick Road in the centre of Ballarat on the right side of the Midland Hwy facing north 5331 2113. As nissannewby said above, boost should not be more than 12 psi & with sensible (correct) fueling, if you are running standard size tyres, should get about 85-90kw. Dynos do vary in readings. Is your exhaust Nissan standard or have you fitted a larger one?
Cheers

[teza04]

thanks for the comments, i am running 285/75/16 muddys bf goodrich, and havent done anything to exhaust yet.is it worth the cost to put these 3 inch exhausts on that i read about in 4x4 mags. this 4.2 is not efi but mechanical so i am confused as i went to opposite lock in ballarat and they said you cant get chips for mechanical fuel injection, and a dyno would do very little as well, keen to hear from anyone if a dyno is worth doing. how do you check the boost and adjust it ,is this done on a dyno ?? thanks

[Rip'n'Shred]

A diesel expert can wind up the injector pump to increase the fuel that gets injected, and increase the boost to compensate the extra fuel. A 3" exhaust will get rid off the extra gases quicker. Same as a chip does on efi.

You will defiantly feel the result.

[nissannewby]

3" exhaust is certainly worth it it will help with your response and will lower your egts slightly and sounds sick as well :). As for the dyno if you are going there to improve they are the best way of netting gains out of your donk they have all the correct tools to make sure your air/fuel ratio is correct so you dont go doing any damage to the engine. If you get to a good tuner tell them what you want say 12 psi and i want it to tow reliably all day everyday for eg and they should be able to get it singing for you just the way you like :)

[Dingo55]

thanks for the comments, i am running 285/75/16 muddys bf goodrich, and havent done anything to exhaust yet.is it worth the cost to put these 3 inch exhausts on that i read about in 4x4 mags. this 4.2 is not efi but mechanical so i am confused as i went to opposite lock in ballarat and they said you cant get chips for mechanical fuel injection, and a dyno would do very little as well, keen to hear from anyone if a dyno is worth doing. how do you check the boost and adjust it ,is this done on a dyno ?? thanks

tesa, can you tell us what year your GU 4.2 is? As the other guys have said, yes a dyno is the best way to determine the current performance level of your GU, ie current boost, current exhaust gas temp (EGT) & current power output at the rear wheels (kw & torque). Have a look at the link to see an example of what info a dyno will give you. http://www.youtube.com/watch?v=ZijIm8ZiHnU&feature=related

The 285/75/16 (32.83") tyres you are running are non-standard size, so that will cause your GU to perform slower (for want of a better word) than if you were running standard tyres (31"). Also, unless you've replaced the speed cog, your speedo reading will be inaccurate. When your speedo is reading 100kph you'll probably be doing about 105kph or thereabouts.

The standard Nissan exhaust meets ADR but doesn't provide the best level of engine performance, hence you can gain power, torque, fuel & EGT efficiencies by fitting an aftermarket performance exhaust, normally 3" for a 4.2, either with or without a dump pipe off the turbo, but a dump pipe will improve engine efficiency. Not sure in what context the guy at opposite lock's advice was that ' a dyno would do very little'. He may have been suggesting that a dyno without then fitting a 3" exhaust would not give you any increased performance, but at least by putting your GU on a dyno you'll be able to see what boost it is currently running & what kw it's producing at the wheels. Even without fitting a 3" exhaust, a good tuner should be able to tune your GU for best fuel efficiency for towing, taking into consideration your lager than standard tyres.

Also, don't know what type of air filter you are currently using, or how clean it is, but a dirty/old air filter will inhibit air intake & will reduce engine performance/efficiency. In the link you'll see they fit a K&N air filter. They are a quality filter that will last the lifetime of your GU, but because they are an oil based filter they will clog more quickly off-road. For on-road use I think they are the ducks guts, but that's a personal opinion. To overcome off-road clogging, you can carry a standard filter & swap out the K&N before you hit the dirt/dust.

Is your fuel filter due for a change? How many k's since your injectors were last serviced?

cheers

[teza04]

had the dynotune done and went from 59kw at 3000rpm to 78kw at 3000r,apparently it was still on standard nissan settings so has been boosted , they didnt find anything wrong which is a relief, next job on the list will be a 3'' exhaust at a later date, thanks for all the feeback excellent site to get knowledge from

[Rip'n'Shred]

Good result

[olmav]

thanks dingo that helped me out heaps