Ah well, a fun three hours spent stripping down cleaning, drying (dessicant went from brown to white in the oven ) and putting back together of compressor. Nothing obvious on show, everything moved/worked as expected.

that mug is empty !

How strange, would of thought of at least a worn piston or bore. If it dont work.......burn it!

If the IId tool cant fix it.......burn the FF.

If the FF cant be fixed......buy a Land Cruiser!

If the LC cant be fixed..............................................BUY a horse !!

The non-return valve may have been sticky (in the centre of your photo, rubber seal with the small spring that sits behind the metal disc). If it fails to shut on the return stroke of the piston (sucked shut) then the air won't move anywhere, it's just go up and down the bore and hence static pressure increase when filling. Likewise if the air intake is blocked. If the cylinder and/or piston ring is also worn the same will happen (air will go past the ring) but usually it's a gradual process of taking longer to raise over time before failing and not an intermittent issue like yours.
It could still be the pressure sensor wiring itself, a break in the wiring somewhere or corroded connection. I posted in another thread somewhere about what should be expected on each of the 3 wires at the sensor (5V supply, ground and return signal voltage), it's in the electrical workshop manual.

If it does come back I have a spare cylinder head from my old compressor if you want to try it instead of forking out for a complete new compressor.
I rebuilt my compressor using Meerbuschs kit (new cylinder head, piston ring, dryer etc. etc.) as I thought mine was slow to raise only to make no difference. I found a leaking airbag a few months later so the original head was fine.

Fingers crossed though, it might have just needed a clean out and it'll be fine now.

Thanks for the input weejock, and also for the offer of the spare cylinder head. There was a bit of muck on the "triangular" shaped rubber washer under the small spring, but wouldn't have thought it to be enough to cause a problem.

Will have to see how my latest effort works out, and may trace the wiring, had thought about this too; such tiny fragile wires! .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

@ weejock

Is it possible to bypass the sensor by looping the wires in the connector (e.g. disconnect and wire Pin 1 to Pin2 to complete the circuit)? Even if so, I guess the car would throw a pressure/sensor fault when demanding air ?

Just thinking about ways of testing the wiring given my fault is intermittent. If I did the above and still got the same fault then it would show it to be the wiring?

Just run the Access to Off Road test: 2 minutes and 6 seconds.... .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

You seem to be going backwards Joe,

What's next then?? Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

All I am doing is trying everything I can think of to solve this problem before shelling out on a new compressor. A learning process (labour of love type thing) and hopefully useful for others should they experience the same problem.

So having:

replaced the reservoir sensor
refurbished the valve block
refurbished the compressor (and fitted new piston ring)

next step is possibly to replace the wiring, check the other valve blocks, check the ECU (?).

Replacing the compressor is the easy way out!  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

You can't bypass the pressure sensor. You can check the voltage on the yellow wire at the sensor, it probably should be 5V (standard sensor reference voltage). Likewise the white wire should be ground. The other wire will be anywhere between 0V and 5V and be proportional to the air pressure. You could measure at the sensor and ECU and see if they tally.
You could try measuring the resistance (continuity) of the wires to check for any issues (Insulation Resistance testing them would be more useful but requires an IR tester). Simplest way to rule out the wiring without resulting to expensive tools is to run additional 'jumper' cables from the sensor to the ECU and leave it like for awhile. If it goes away there's your issue!

By the way just over 2min from access to off road is about what I get (with reservoir full at the start). My off road height is higher than normal though, seem to remember it was between 90s to 2m when my off road height was at factory spec.

I'm just wondering if the reed valve Hayland mentioned before is under that copper intake filter and might b worth a look?

Reed valve is in the top of the piston....

Could still be that copper filter, their pretty cheap Joe, maybe muller it off and see if that makes a difference... Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Inspired by this thread I have dug out the old compressor that I rebuilt using one of meerbush's kits, I found the reason it didn't work after I rebuild it was there was a split in the pipe that connects the compressor to the car. When I rebuilt it I put it in the car to try it and couldn't hear the leak. The error message came right back so being a grumpy I ordered a new one from paddocks which is now in the car. Running it on the bench I could hear the hissing. I'm sure joe has probably checked this by now but I thought I would post my findings. And to say I now have a working compressor for sale
Roger.

Useful info Roger Not checked for leaks, but given my fault is intermittent (can go for a couple of days without fault, seems unlikely - though I won't rule it out

@ Haylands - reed valve - the flappy thing on top of the piston was flush and looked like others I had seen, so guess it should be OK.

BTW car performed fine today for 55 miles then faulted 2 minutes from home

@ weejock

Thanks for the input regarding shorting the sensor wires, thought as much. Will have to see if I can route some wires back to the ECU, can't think of it being anything else. Will do a resistance test along with some judicious wiggling! (of wires ) .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Managed to get a different fault out of the car today, after trying out a bit of up and down. This time it was the:

"compressor temperature static when operating" (or words to that effect)

Also been monitoring when the usual fault (pressure static when filling) occurs:

1. Almost immediately after startup/setoff
2. Not long after coming up from Motorway to Normal height

All this (for me) points to a knackered compressor. I have a new one on the way from Germany  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

At least you now know what was giving the main problem , just a shame it was not the cheaper option like the pressure switch. If it dont work.......burn it!

If the IId tool cant fix it.......burn the FF.

If the FF cant be fixed......buy a Land Cruiser!

If the LC cant be fixed..............................................BUY a horse !!

Joe90 wrote:

Managed to get a different fault out of the car today, after trying out a bit of up and down.

I wondered where this thread was going for a minute....

It does look like it's the pump then, hope the new one fixes it alright, can you post an "up and down time" when you put the new one on... it'll give me an idea how far away mine is from demise...

Cheers Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-