Hello

The Car was doing great but a few days ago it started juddering only when going uphill on hard acceleration, on flat highway can go at wot no problem, no juddering.
Going uphill on cruising speed not juddering.
It only happens uphill, tried many many times, on flat road can go at full wot on all gears no problem but if road turns uphill going on hard acceleration it judders.
I just changed spark plugs gaped 0.031" but still have same problem.
Tuned, running K04+, no cats, intercooler.
I have this setup since a year with no problems but suddenly this juddering thing just appeared.
Please..any help ? Where I should begin looking at

 

I'd image in tank fuel pump is going bad but that's just my thoughts.

 

How long ago was the fuel filter replaced?

 

does your car have gas in it?

 

Never, 43,000 miles on the clock.
I heard fuel filter was not a serviceable part.
Where is located ?

 

There is no fuel filter on the lnf. What ud call a filter is attached to the in tank pump, so ud have to replace the pump

 

How much of an incline are we talking here?

 

I would say a +25 degrees hill is enough

If going steady at 3500 RPM on 5th gear on flat road and then the road becomes uphill (25 degrees for example) changing to 4th and push throttle I get a BIG judder but if keep steady on 3500 at 5th gear uphill there is no juddering.