GQ down on power and idle rough when hot

[Patrol Freak]

G'day all
I have a '96 GQ Patrol RD28T that has done just over 300,000km and most of the time it runs sweet but after a long drive when it gets hot it starts idling really rough almost stalling sometimes and the power drops significantly, on hills it seem to die in the ass alot more too again when hot. I did a search and didn't find any help, my dad asked a diesel mechanic at work and he said it sounds to him like its not breathing properly, and a build up of soot in the stock exhaust could be causing it? Any and all help appreciated.
Cheers
Jarrod

[Robo]

Don't know the engines habits personally, why don't ya try servicing the cooling system inside and out and see what happens from there.
could be a cheap fix to your troubles.
Cheers

[Killametre]

What kind if smoke do you get when missing white/ black or none? When did you last service the air and fuel filters? When it is hot and running rough try cracking the injector line to each injector one at a time and see if one makes no difference if so the the problem is related to that cyl then you could try swapping injectors around and see if the problem follows it. When you say hot is this overheating or just operating temp? Of overheating also check for blown head gasket bubbles in coolant with the radiator cap off

[Patrol Freak]

Cheers mate, what would servicing the cooling system involve doing?
I'm not 100% about smoke colour but I don't think it is blowing excessive amounts of smoke any colour, It doesn't over heat, but give tell you were the temp gauge sits as I need to replace that.
Cheers

[Killametre]

Also would pay to check boost pressure and exhaust gas temp x turbo

[Patrol Freak]

Yeah that's one thing I want to do is install the gauges to do that.

[Robo]

there's plenty threads - posts on here about flushing cooling systems.
Or you can get it professionally done.
Also have a look at thing like filters these are the obvious first ports of call.
Tony, YNOT has posted a thread on maintance you should check it out.

[Patrol Freak]

Will do, thanks mate. Pretty keen on learning how to do my own maintenance I'm only 17 but I know how to do oil, air and fuel filters but that's it, all of which have been changed a recently, My dad and I did them.

[Robo]

Well, you picked a good vehicle as your first car.
A Nissan Patrol.
think thread was " preventive maintance"

now if only I could get my 2 oldest to get rid of the Gm and Tonka cars.
can only live in hope.

[Patrol Freak]

Haha Yeah well it's dad's at the moment and he has had her since new and I know she's been taken care of but he wants a new Patrol so he said if I find out what's wrong with her and pay to fix it she is mine :D
Found that thread too was a great help saved it to my PC so I can go back when I need to, very helpful thanks again mate.
They'll come to their senses eventually... Hopefully haha

[Patrol Freak]

Problem hopefully solved :D the bloke at West End Diesel (I think that's it) said it is some part in the IP that when it gets hot it expands and doesn't let enough fuel in. So she's getting the pump and injectors done next week, fingers crossed that's what it is.

[HammerBuilder]

Let me know if this doesn't fix it as I also have a 2.8 GQ done 320,000k's
The fuel problem I found was at the back of the injection pump theres a return line Bolt & union, in the middle of this bolt there's a gauze, What ever you do don't try & get the gauze out to clean it just get a can of carby cleaner or brakeclean & spray until no more little bits of crap come out then refit after it dry's then take it for a drive.
As for draining all the coolant & flushing the block has a 14mm bolt under the exhaust manifold at the back of the block undo this only when cold, & take the radiator out & back flush it well with your garden hose, whislt your at it get a new thermostat from nissan & also a new radiator cap for $19
If you don't undo the 14mm bolt you will not drain all the coolant from the engine as it holds about another 6 liters in the block weird I know.
Refit 14mm bolt, thermostat & then radiator then fill with coolant & what ever you do don't forget to bleed the air out at both the heater bleeder near the firewall please remeber to turn heater control to hot & if yours has it next to the battery in the top radiator hose has a white plastic sort of bleed screw.

Mine is going great now although I also did change my head gasket 2 weeks ago & also done the EGR blocking plate then went on good old Ebay & got the matching pair EGT & Boost Guages realy good & work very acurately according to dyno figures.
Now mine doesn't get over bout that white dot on the factory temp guage. compared to before when it nearly always went up to the line above that on long hills.

Hope this helps TonyD