It might not be the OP’s answer but I read that as meaning
slow oil return means low oil level and thus none to feed pick up so Accusump kicks in.
[quote=jbs]I have a few questions regarding the replacing of the pressure switch.
I suppose I have to start with :
- put the key on ignition and open the valve manually (join 2 wires), then
- pressurize the Accusump to 60 PSI (at the air valve) to force all the oil out of the Accusump
wait a few minutes until the oil has settled in the oil pan
Is it now safe to unscrew and replace the pressure switch ? Or will there still be any pressure left in the oil lines ?
This might be a silly question, but when I have replaced the pressure switch, then air will have entered the Accusump oil lines. How do I bleed the air from the oil lines ? [/quote]
Anyone knows an answer to the above, please?
Thats what I’d expect with two resistors wired in parallel, if the sensor & switch had the same resistance the voltage between then would be 6v.
This is all getting a bit heavy for me !!! 
Just got my car back from service today and one of the advisory items is that my accumsump is not working. Great!
I won’t be doing the investigating that is described above, but ideally need the thing working before next weeks track day at Abbeville!
Will you name and shame the dealer? That so called service is disgraceful imho.
Where did you get it serviced? Trying to think who is in the Reading area…
I’d have expected a phone call 1st and a discussion of whether you wanted them to investigate rather than handing the car back with a “fault”.
Just a thought but do they really know how it works?
[quote=stevegreen]Where did you get it serviced? Trying to think who is in the Reading area…
I’d have expected a phone call 1st and a discussion of whether you wanted them to investigate rather than handing the car back with a “fault”.
Just a thought but do they really know how it works? [/quote]
It was B&C chaps, but has made me question if they know how it works. And no, there was no phone call - presumably because any investigation work would have taken them outside of the Saturday morning working timeslot, so they chose to do nothing.
I’ll have a look at the system/pressures etc tomorrow to gauge my own opinion, but am lining up a trip to see Chris Randall at Hoffmans during the week.
I religiously wait for the priming noise to end before I start the car each time, and am always aware of a level of pressure on the gauge in the boot when I’m looking in there.
But I was told today it wasn’t even holding any oil, so wouldn’t that mean no priming noise, and no pressure?
I’ll read up a bit on the owners manual and educate myself further.
if it’s not holding any oil, then either the switch is constantly assuming less than 40 PSI engine pressure (and sending signal to open the valve), or the valve is blocked in the open-position.
Measure the voltage at the 2 pins of the switch and you should know.
Verify your oil level in any case. If the Accusump is failing to hold the oil, then your oil pan should be filled with way too much oil.
Mine has given me countless headaches too. I have replaced it with a baffled oil pan. It’s only going back in, when I have found a heavy duty pressure switch and valve.
Does a larger Accusump have a more heavy duty pressure switch and valve?
Good luck - there’s been a few posts recently about Accusumps and I recall JDS posted with some practical advice on testing.
Right. Whilst I don’t have the equipment or technical knowledge to interpret the results the testing procedure jbs has gone into above, I have carried out some basic observations on my accusump system, in conjunction with the owners manual.
Here are my findings:-
Pressure on Accusump gauge when cold (engine not running) = approx.24psi
Manual suggests this should be 7-15psi, so a little high
Pressure following ‘priming’, i.e. pre-ignition = approx.29-30psi
Pressure following ignition (not immediate, but within 1-2mins = approx.90psi
Manual suggests this should be approximately 80psi initially, so again a little high, but then falling to between 30-40psi
After about 5mins of idle = some pressure change activity. Initial slight drop to 85psi, then shortly after; a quick drop to 60psi, then a steady drop to 50psi. Over the next 5mins or so the pressure creeps down to approx.42psi, and by this time the engine temp is now showing 82�C.
After about 15mins of idle = the continual but slow creep downwards has taken pressure to about 38psi, with engine temp at 86�C.
After about 20mins of idle = pressure seems to have stabilised at approx. 37psi, with engine temp at 87�C.
After about 25mins of idle = no change to pressure, so engine off.
After a further 1hour = car has been left to cool, and upon return the pressure is still showing 37psi.
So with the exception of some slightly high initial pressures, and pressure being held after a long period static, in my opinion, the accumsump system appears to be operating in accordance with the manual.
What do others say?
Operable or inoperable as suggested by my service notes…
When you turn on the ignition, not starting it, does the system pressurise the engine? You should be able to hear the oil gurgling through the engine.
Yep. Always does, and I always wait for that to stop before turning the key the rest of the way.
From what you have described, it sounds like its working fine to me then. It may have a slightly high air charge pressure, but thats not the end of the world and will do no harm to anything.
+1
You can adjust the pre-charge pressure to 7-15 PSI at the Schraeder valve.
Nope, it is all the same as I have a larger one 