Right where to start
My air suspension is very slow at going up from access mode to normal ride hight I have tried by replacing the o ring seals on the main air block I have still to do the crossover ones.I have plugged the IID in and I have got a reading of 154 psi at Reservoir I do have a new piston ring kit form bagpipe Andy just looking for a bit of advice if anybody has had the same issue or similar I just cannot seam to get any further with it

Besides the obvious checks for leaks, if this is the maximum pressure you are obtaining then if you have no leaks and the pressure sensor is reading correctly, then your compressor may need an overhaul. AFAIK the cylinder pressure should be up to 180, not 154, which would also explain the slower operation when the car returns to normal height. As you probably know, O/H kits are quite cheap.

I am going to give a overhaul and I will have to order a dryer kit aswell might aswell do that while it’s off hopefully it will be better when it’s all being done thanks for the heads up 👍

Have you tried removing the brass sintered filter on the pump inlet ?
Could be blocked - although I think the pumping up time should be supported by air from the reservoir NOT fresh air going in.
I think the filter has more of an effect on height reduction time Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 145,000 miles & climbing
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

I will give it a try when I put the new piston ring in think I have a spare one in the tool box

Changed the orings on all main valves and cross overs and also did the ring in the compressor and clean out the brass filters and good news is the pressure is up to 184 psi and takes about 1min20seconds to get to ride hight 👍