Revs fluctuating under load

[ragrim]

Ok its hard to explain this problem but ill give it a shot...

Going up a hill in my VR V6 Auto in drive, car is in 4th gear doing 100kmh RPM on 2000. as i start going up the hill and there is load on the car my revs will start bouncing around from 1800 to 2200. If i drop it back to 2nd or 3rd it doesnt do it as my revs are 3k+

Its not just big hills, its basically any time im in drive with revs around 2000 and under load, its fibe when cruising on flat highway 100-120kmh

Since ive had the car i have put a new motor in it (220,000k) new fan belt, plugs, leads, oils, fluids, cleaned intake manifold, new exhaust and taken off every sensor cleaned all connectors and checked wires for breaks.

I have a feeling its one of 2 things, gearbox slipping or fuel supply issue. Its more likely to me that its a garbox issue but its so unusual it doesnt make sense.

Would be great if someone else has some insight on this cause its bugging me not knowing the problem.

[Brett_jjj]

It might be a torque converter lockup problem,it might be locking then unlocking.Try doing an error code check,heres a link on how to do that..Checking error codes VR/VS (Revised)

[BoNeZ-01]

Yeah could be the clutch bands in the transmission are badly worn, meaning it might needs reco'd, or could be fuel pump/filter issue.
Did you use the same injectors/regulator from the old engine on the new one? Could be an issue there too.

[chrisdoesitbetter]

can you smell the catlytic converter? it may be blocked if its not the above

[Nanos]

sounds like the trans is slipping. sounds exactly like my auto only few weeks back. turns out it was 3rd/4th gear clutches shot.

get a trans place to have a look at it.

[hako]

I'd also check the Throttle Position Sensor (TPS).

[Brucefromruse]

Same problem, plugs, leads, coil pac. purrfect now.

[ragrim]

Throttle position sensor has been changed, plugs and leads also been done...

I did have an error code pope up the other day just as i started going up hill, and it turned out to be transmission slipping allthough the box wasnt slipping at all that time.

ive since added another 500ml of tranny fluid for shits and giggles and it appears the problem has seriously decreased but it is still there, tranny has more than enough fluid so it cant be that.

[Brett_jjj]

tranny has more than enough fluid so it cant be that.

Are you checking the trans fluid with the engine running and when its up at operating temp?

[ragrim]

yeah engine running, operating tempreture and checked it while its in park and in drive. level is spot on perfect, now its slightly over full since i added a touch more.

i think i need to go see an auto place as thats about all it realy can be.