EAS pump running too often

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wammers said:
You answered to quickly. And your point is?
Click to expand...


If you want to be accurate, be closer to the accurate:rolleyes: no offense but I know about pressure, may be down on other points
FYI: Doing fiscal measurements on oil/gas/BS&W at work and need to be accurate, sometimes as high as 700 Bar the numbers makes a huge difference
Apart from that, not really fussed:) To me 14.5 is fine but 14.7 what the hell it isn't fiscal:D:D:D:kettlepot:
 
Druim said:
If you want to be accurate, be closer to the accurate:rolleyes: no offense but I know about pressure, may be down on other points
FYI: Doing fiscal measurements on oil/gas/BS&W at work and need to be accurate, sometimes as high as 700 Bar the numbers makes a huge difference
Apart from that, not really fussed:) To me 14.5 is fine but 14.7 what the hell it isn't fiscal:D:D:D:kettlepot:
Click to expand...

If you used 14.7 you would be erring on the side of caution. At 700 bar whats 140 psi amongst friends. Point is Land rover seem to have had several people using different versions of bar. Which makes people that get easily confused more confusedider. :D
 
Workshop manual, fairly accurate
Mounted on the valve block is a pressure switch which
senses air pressure and signals the ECU to operate
the compressor when required.The compressor will
operate when the pressure falls between 7.2 and 8.0
bar (104 and 116 lbf/in2). It will cut out at a rising
pressure of between 9.5 and 10.5 bar (138 and 152
lbf/in2).


From electrical diagran, - not that accurate
8.50 Bar - 120 psi
10 Bar - 140 psi


Worst case holding the two together hysteresis = 18 psi (WSM = 22 psi)


All in all, the pressure switch used are not the best or mounted in wrong position, tank location would probably be better
 
Druim said:
Workshop manual, fairly accurate
Mounted on the valve block is a pressure switch which
senses air pressure and signals the ECU to operate
the compressor when required.The compressor will
operate when the pressure falls between 7.2 and 8.0
bar (104 and 116 lbf/in2). It will cut out at a rising
pressure of between 9.5 and 10.5 bar (138 and 152
lbf/in2).


From electrical diagran, - not that accurate
8.50 Bar - 120 psi
10 Bar - 140 psi


Worst case holding the two together hysteresis = 18 psi (WSM = 22 psi)


All in all, the pressure switch used are not the best or mounted in wrong position, tank location would probably be better
Click to expand...

Correct a bit misleading. However if i am in an airliner landing at a high level air field in fog i hope the altimeter is using 14.7 as a reference. :D:D:D
 
Thanks for all the suggestions guys, to be honest I'm not seeing much which fits the symptoms though. I thought about the thermal cut off and pressure switch, but why does it settle down after a while? I did wonder if there might be a constriction in the pump to tank circuit, such that the pump cuts in the local circuit builds up pressure and the switch cuts out, then the pressure bleeds away to the tank and the cycle repeats, eventually the tank is up to pressure and the pressure is held and the pump switched off. that would fit the symptoms, but is it a likely scenario? I'm not that familiar with the inside of the valve block. In answered to the questions asked. no the bonnet isn't open, this is whilst driving and no I haven't rebuilt the valve block, although I have considered it.
 
Rudolf said:
Thanks for all the suggestions guys, to be honest I'm not seeing much which fits the symptoms though. I thought about the thermal cut off and pressure switch, but why does it settle down after a while? I did wonder if there might be a constriction in the pump to tank circuit, such that the pump cuts in the local circuit builds up pressure and the switch cuts out, then the pressure bleeds away to the tank and the cycle repeats, eventually the tank is up to pressure and the pressure is held and the pump switched off. that would fit the symptoms, but is it a likely scenario? I'm not that familiar with the inside of the valve block. In answered to the questions asked. no the bonnet isn't open, this is whilst driving and no I haven't rebuilt the valve block, although I have considered it.
Click to expand...
Just a thought, is there a lot of clicking from the valve block when the compressor runs too often? If so it could be a dodgy height sensr assuming leaks have been eliminated, otherwise fit new O rings to the valve block and pay particular attention to the non return valves, also check/replace the diaphragm.
 
Last edited:
Merry Christmas one and all. Just for completeness I should say (albeit rather late) that Datatec hit the nail on the head. Checking the height sensors revealed erratic responses from the OSF and changing that solved the problem! I think it was just changing height all the time and running out of air, although you could not see any real height change. Onwards and upwards to the next problem, see new thread on blend motors...
 
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