Fault finding on 4.5 patrol

[GreenMachine]

Good day all,
I would appreciate some advice please.

Recently (last week) bought a 2000 Nissan Patrol GL 4.5 with +350K km on the dial.
Now to start off, I am very aware that a bought an old mule and don't expect her to perform like a race horse and I do expect most parts to be fairly worn.

I am planning to do the recon and turbo kit later on, but for now just want her humming along until I can save up the cash.

The problem I am facing reads as following:
The truck (can't call it a car, its a big green machine) was fitted with a TNT exhaust and dastek chip by previous owner. SAC sticker on the back suggest that they did the mods and tuning. The dealer I bought it from sent it in to have some idling and performance issues addressed and this is what they did: Chip and harness removed, both fuel pumps and fuel filter replaced and spark plugs replaced. This is the point where I drove it off their showroom.

First noticed that the engine is shrugging/missing and almost dies going up hills. (Had to drop to second going up hill at Harties.)
The missing is inconsistent and therefore I kind of think it is a fuel issue rather than spark.
Also read somewhere on a forum here that the timing needs to be reset after removing the chip.
So I took it back and had timing adjusted. She pulls much better now and also more responsive.
I can go up hill in third now but still losing power and engine is still missing beats sporadically.
Went back to dealer, was mentioned that it could be dirty injectors and I have to leave the truck there for a few days so they can 'have a look at it"
I travel between SA and Botswana regularly and cannot afford to let her stand for days.
So I through a bottle of injector cleaner in the tank and gave her a run.
Not sure if it is my imagination or not, but she did feel a bit more responsive and missing fewer beats, but the problem is still there.

Please can anyone help me with fault-finding myself so I can get her sorted on the run?

[Marino4x4]

Hi Tertius

Welkom hier. Vat jou kar vir Graham Cummings (Forum naam: PathMaker). Hy is die boffin as dit by die karre kom. Hy ry self n 4.5. Hy is in Valhalla. Jy kan hom op o8drie 41sewe sewe 503 kontak.

Groete

Welcome here. Take your car to Graham Cummings (Forum name: PathMaker). He drive a 4.5 and is the specialist on these cars. He is in Valhalla. Call him on 08Three 41 seven seven 503.

All the best

[GreenMachine]

Thanks,
I will give him a bell.

Thinking I will try cleaning the MAF sensor next, but will see what Graham says.

[David M]

I have the exact same problems with my '98 4.5 with under 200 k on the clock and it is going to Graham for the week next week so that he can try figure it out.

The injector cleaner also worked for me but they may need to come out and be reconditioned.

Mine has a Maus conversion and the chip was also removed by the previous owner.

Mine is also intermittent but seems to be worse when hot so am thinking it may have something to do with the heat coming from the branches that is affecting something. I have wrapped the branches with ceramic tape to try and reduce temperatures.

Mine also responded to advancing the timing and ran beautifully but was pinging under load so had to retard it a bit.

I have also replaced the ignition leads which also helped a lot.

All my problems are between 2300 and 3100 rpm and everything is well below and above these revs so it is unlikely to be fuel pressure but it is a possibility as the aftermarket replacement pump may not be sufficient.

You can also try cleaning the PCV valve as it may be blocked by now with your mileage.

MAF sensor is also a possibility.

Will give feedback next week once it comes back from The Patrol Professor.

[David M]

Just collected my Patrol from Graham and the smile on my face is so big that the stretch marks on my face are going to be worse than a new mother of sextuplets will have on her tummy.

It is accelerating up hills in 5th that I could not hold my speed on in 3rd before and I am going to go cruising around down Ricster's part of the world tonight looking for hot hatches to teach a lesson or two to.

The problem - A previous owner diligently had the fuel pump replaced with a genuine Nissan one about 30 000 km ago. The only problem being that said pump looks exactly like the Patrol one but is actually for a Sentra or something similar so fuel pressure was just not there but symptoms pointed to everything other than the pump.

The chances are that a Patrol pump was ordered from Nissan and they supplied the wrong one (Why would anyone have purposely have ordered a Sentra one?) and this may also be the case with Tertius's Patrol and possibly others. The only way of telling the difference is by looking down the outlet hole and checking the size of the inner hole where the Patrol's hole is double the size.

[Peter Connan]

Glad you're sorted!

[Tinus lotz]

Happy to hear mr cumming waved his box of tricks again....

[Jorrie]

I had similar issues with my 1998 4.5 and Graham solved it for me. Last week he resurrected Juan Leslie's 4.8 and Juan is now a very happy man. Need I say more. Take it to Graham the next time you're in Pretoria.

[Herrie]

I had the same problem and it was also the fuel tank pump

[GreenMachine]

Thank you gents for all your input,
I will have to make a plan to get it to Dr G.

Currently in Botswana and not sure when heading back that way, but I will have a gander at the pump itself.
Maybe even try to get a copy of the receipt from the repairer.

My Patrol idles unevenly and stutters through all revs so it would be a safe bet to say it is either pump, injectors or spark or even a combination of some.
Can't wait to have her running smooth again.

Due to the high miles there is a couple of things that need attention, brakes, transmission and some electronics but still happy I bought this absolute beast of a motor. Would not buy anything else with that kind of miles on the dial.