no power till turbo kicks in

[effmtv8]

Have a 2007 2.5 turbo diesel d40.
Yestrday on the way to work I got off the motorway and the ute had really slow acceleration until the revs hit 2250rpm and the turbo kicked in. Above 2000rpm the ute drives as normal but under that it is very very sluggish and really slow from a standing start.
have reset the ecu and cleaned the maf sensor aswell as putting a fuel system cleaner in with no luck. My first diesel so have no idea where to go from here.
any ideas?
Thanks

 

[nismo4x4]

check theses vacuum hoses

check theses vacuum hoses

 

[effmtv8]

Vacuum hoses are in good nick

 

[kernels]

Could be the vanes in the turbo sticking. Rev it a bit and keep an eye on the actuator on top of the turbo, it should move up and down.

And double and triple check the vacuum hoses.

 

[DieselTuner]

The navara's are really bad for the boost solenoids failing.

Its almost directly behind where the oil catch can is in the above pic.

put a boost gauge on it.

 

[Old.Tony]

Being a 2007 I'd expect the vacuum hoses to be a little perished. I think mine are, I'm going to inspect mine tomorrow - when the engine is cold I'm getting a minor surging every couple of seconds, which goes away when the engine is warm. If it's not my hoses I will be looking closely at my timing chain! If you can turn one of those hoses on its barb it's toast, toss it and its mates (replace everything from the vacuum pump on the right hand side and over). The actuator should move at idle too - about 3-5mm in a semi-irregular fashion.

You should be developing boost from about 1200rpm, with good boost at 1700-1800 but nothing like the peaks you'll get at the 3500rpm mark where max power is developed (peak torque at 2,000rpm). Still, at 1500rpm I'd be expecting to see somewhere between 5-10psi of boost if the system is working well. With the MAFS clean, it's down to boost sensor (low on the right hand side of the intercooler) and turbo's condition as to whether or not the air gets in.

I don't suspect a fuel problem just yet because if you have a fuel problem down low (eg SCV dirty) then up high you have nothing at all. If yours is going good up high, it might be producing enough vacuum to get the actuator moving and the turbocharger up to speed to provide enough air. If that's the case it should belch a fair amount of black smoke with the turbo unspooled - how's that look?

 

[jjohn]

Mine went like that. As said check vacuum tubes but mine was the electronic boost solenoid. Nissan will have one in stock because it's a common problem.

 

[nismo4x4]

as tony said above my vacuum hoses were rubbish and just perished in my hands and i have an 06 model

 

[Connaught]

i just did mine on my 07, made a huge difference, 3 meters of 6.5 mm hose from supercheap was 15 bucks, and i got 20 cm left over, even did the little piece off the intercooler to the boost sensor

mine all where tight on the barb, but left black rubber on the fingers after i touched em, it is possible for rubber to become porous over time as it deteriorates

 

[DieselTuner]

Being a 2007 I'd expect the vacuum hoses to be a little perished. I think mine are, I'm going to inspect mine tomorrow - when the engine is cold I'm getting a minor surging every couple of seconds, which goes away when the engine is warm. If it's not my hoses I will be looking closely at my timing chain! If you can turn one of those hoses on its barb it's toast, toss it and its mates (replace everything from the vacuum pump on the right hand side and over). The actuator should move at idle too - about 3-5mm in a semi-irregular fashion.

You should be developing boost from about 1200rpm, with good boost at 1700-1800 but nothing like the peaks you'll get at the 3500rpm mark where max power is developed (peak torque at 2,000rpm). Still, at 1500rpm I'd be expecting to see somewhere between 5-10psi of boost if the system is working well. With the MAFS clean, it's down to boost sensor (low on the right hand side of the intercooler) and turbo's condition as to whether or not the air gets in.

I don't suspect a fuel problem just yet because if you have a fuel problem down low (eg SCV dirty) then up high you have nothing at all. If yours is going good up high, it might be producing enough vacuum to get the actuator moving and the turbocharger up to speed to provide enough air. If that's the case it should belch a fair amount of black smoke with the turbo unspooled - how's that look?

Ive just finished diagnosing this exact problem on a car last week. Started off having a few months of this surging that I could not pin point, followed immediately by some rough running at idle.

New injectors fixed it 100%, even though the old injectors tested perfectly within spec (how they test these and say no problems Ill never know, I give up sending them for testing any longer)

 

[Old.Tony]

I might try injector cleaner then, and see what a whole bottle of Chemtech Diesel Power does to it (in about 40L of diesel that I have left in the tank!).

 

[DieselTuner]

Its worth a shot thats for sure. We tried a couple of various ones on this car but it was to far gone.

Double check the boost though, just because the symptoms are the same doesnt mean the problem i fixed is exactly what you have.

That one had 180K on the clock by the way.

 

[Old.Tony]

145K on the clock here, boost pressures seem to be fine. Power delivery seems normal, economy is normal. At the moment, it's a minor irritation at idle. I don't think it's got anything to do with the HO2S check, it's not a high enough frequency (which I wouldn't notice anyway, this surging is noticeable). I can't do anything until tomorrow evening anyway, so there won't be any results until Wednesday night at least.

 

[77-dogg]

I just had this problem new boost lines **** power down low normal up high. it was my boost vavle where all your boost lines run to best 105buks I have spent

 

[joshua0812]

Having same issue, Did anyone get their truck sorted with this problem?