Carbie problem ??

I was driving my Patrol and lost acceleration. at 1st it was just when going up a hill , then it became in general as I drove. It would not rev higher that 3000rpm. I pulled over, played around with carbie ( I am not Mechanically minded ) it was fine again until after sometime ie 20km it started it again, The NRMA tow me home it is ok at the moment but have only driven it a few km , but have driven up a hill no problem.
Prior to this happening, I changed the spark plugs, oil and fuel filter, i drove 300km or more , filled up at a small town servo drove another200km , 60kms of which was dirt, well mud as it was raining.
I thought it may have been the accelerator cable but the NRMA guy said no and that it was most likely something in the Carbie playing up.
Any ideas where I should start looking?

What engine?

check the fuel filter again - dirt or water may be blocking it, even though you replaced it not long ago. Look for other fuel filters that either Mr Nissan put there, or someone else added

If it is an engine with breaker points in the distributor, check the point gap has not closed up.

That's all I can come up with so far.

its a 3L petrol, 1990 model, it is white

yup it has Dizzy and points, both checking that and checking the fuel filter are on the top of my to do list.
the old fuel filter that i replaced on Thursday B4 it started playing up was full of crud.
was also thinking of replacing the air filter, (was planning to do that regardless of this issue) it does look like its done its job long enuff

sounds like you might be starving it of air, id change that filter first spray some throttle body cleaner through yer inlet while its running then run it hard down the freeway for 20min or so
that should at least rule that out

A mate (with the rb30) had the same problems as your describing for months. In the end all he did was spend a bit of time lubing up the outside of the carby with inox. Free up all linkages, paying special attention to the piece in the below photo. Pull the rubber boot out the way, spray inox and work the shaft up and down till it's free moving. (the photo us of a TB42 carb but the part is very similar. Hopefully this will help.

I checked the fuel filter , all good there
I was unable to check points since none of my 8mm sockets or spanners were small enuff to fit on the bolt to undo it.
air filter is on order.
I have driven it twice now and the problem hasn't reoccurred.
freeing up the carbie linkages sounds like it could be the go , when it 1st happened i played around with the carbie and the problem was fixed for a short period of time

I would be looking at your fuel filters, sounds like one is partly blocked. If you put you foot down, does it rev out then dies i.e staving for fuel

ALso check where the fuel enters the carby as there may be a little gauze ilter

The item on the left of the above photo -is the air cond idle control.

Inox will help if the carby is sticking

when I put my foot to the floor , nothing happened, it was reving at 3000rpm foot to the floor no increase in revs, changed down gear, max 3000rpm, the engine never died nor coughed or spluttered, it just didnt rev above 300rpm, which meant that when going up a hill it lost power and I had to crawl to the top of the hill , which really sux in a 110km zone and you are slowed down to 20km/hr and you have a further 500km to travel to get to where you are going NRMA saved the day but no mechanics were around to sort the problem out so it got towed home