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Discussion Starter #1
Sorry if this is a cross post from another forum, but I need advice and I need it resolved by the end of next week. :shrug:

I know the procedure that is described in the manual to check the oil level.

However, I'm not getting the same pressure readings (pre-charge pressure of 15 PSI and oil pressure of 40 PSI)

Here's what's happened/happening :

I have had an oil change at the dealer's and when I arrived at home the Accusump pressure gauge reading was at 60 PSI.
After 2 hours of cooling down, I checked the pressure again (engine was off) and the pressure was still at 60 PSI.

Today (after 24 hours of non-use) I have noticed that the pressure was at 45 PSI (engine was off). I then wanted to check the pre-pressure and turned the car key into position "ignition"… but the pressure stayed static at 45 PSI…..

Is something broken ?
 

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You may have 2 problems:
1. The accusump is not holding the pressure when the engine is off, as the pressure shouldn't drop, so the air valve may leak. Put soap water and check leak.
2. The pressure switch is gone that's why it won't release oil when the key on.

Check my thread somewhere in LT.
 

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If you turn on the ignition without starting the engine, and the Accusump does not drop down to 10-15 psi...

1) The discharge valve might not be opening and the Accusump is not discharging into the oil system

2) Your "charge pressure" is too high... i.e. the Accusump should be charged to 10-15 psi when the oil is discharged.

My guess is that it is #1

That could be caused by a sticky valve, a bad solenoid, or a wiring problem at the discharge valve.
 

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Discussion Starter #4
Thank you very much for your help!

I did a few more tests this morning:

I checked the Accusump pressure and it was still at 42 PSI give or take. I then turned the key on ignition, hoping to see and hear the discharge, but there was none! The pressure stayed again static at 42 PSI.
After this I started the engine and the pressure raised to 80 PSI !!

I turned the engine off and let it sit for another hour and tried the same steps again. The result: Still no discharge, nor did the pressure change when I started the engine a second time. It remained at 80 PSI.

I also measured the oil level. On my first attempt at pressure 42 PSI, the mark on the dipstick was at 2/3. On my second attempt at 80 PSI the oil level was at 1/4.
 

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Thank you very much for your help!

I did a few more tests this morning:

I checked the Accusump pressure and it was still at 42 PSI give or take. I then turned the key on ignition, hoping to see and hear the discharge, but there was none! The pressure stayed again static at 42 PSI.
After this I started the engine and the pressure raised to 80 PSI !!

I turned the engine off and let it sit for another hour and tried the same steps again. The result: Still no discharge, nor did the pressure change when I started the engine a second time. It remained at 80 PSI.

I also measured the oil level. On my first attempt at pressure 42 PSI, the mark on the dipstick was at 2/3. On my second attempt at 80 PSI the oil level was at 1/4.
Yes, start engine will raise the oil pressure to 80psi. If the assucump whole system is working correctly, when the engine fully warmed to 80+C at idle, the oil pressure should drop to 24+psi. When the oil pressure drop through 33psi, the accusump should discharge, you will see the gauge shakes up and down then settle at around 24+psi.

Assume all you wiring and oil line connected correctly.

1. To check the air pressure, you need to discharge the assucump, then pump air up to 60psi and wait for at least over night.
- To force dischage the accusump, you use 12V wire to by past the pressure switch, then it should discharge. If this doesn't cause discharge, then your electric valve is not working, but this is very rear.
- After discharged, pump air to 60psi then wait over night, at the mean time put some soap water to the air valve to check leak.

2. To check the assusump is working mechanically correctly:
- After the leak check, pump air pressure to 12-15psi;
- Use 12V wire to by past the pressure switch and assume it is working correctly. The other way is by pass the electric valve with a straight pipe :(
- start up the car, the gauge should reflect the oil pressure correctly, when the engine is fully warmed up, ask your friend to press on the gas and release, repeat the circle couple times, you should see the oil pressure goes up and down accordingly. If not, then your accusump is broken, send back to Canton Racing for rebuild.

3. Beg Canton Racing or Gems to sell you a pressure switch, then you will know what is going on right the way.

But I can say 99.9999% the pressure switch is gone :mad: As the Gems dealer in HK told me that the pressure switch is the source.

To top up the oil level correctly (if you have manual valve on the oil line):
1. Discharge the accusump, change oil;
2. Fill up the oil pan to correct level;
3. Close the manual valve;
4. Start the engine;
5. Fully warm up the car, keep the car at 60psi, open the manual valve, then the accusump should suck in oil and show 60psi, then turn off the key to kill the engine;
6. Gauge should should the pressure that you kill the engine;
7. Measure and top up the oil to the correct level.

To top up the oil level correctly (if you don't have manual valve on the oil line):
1. Discharge the accusump, change oil;
2. Fill up the oil pan to correct level;
3. Start the engine, accusump should suck in oil at 80psi;
4. Fully warm up the car, keep the car at 60psi, and turn off the key to kill the engine;
5. Measure and top up the oil to the correct level.

I really got nothing to do to type up so many words :(
 

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Discussion Starter #6
I am so very grateful that you took this much time to write an extensive reply. Thank you!

I tried to measure the voltage on the pressure switch to see whether it would get any power. I hope, this IS the correct switch. See the photo below :



It shows that the switch is getting power, so it cannot be the switch not working, can it ?

If it's not the switch, then it might be the valve not working properly. However, when I start the engine, the Accusump pressure rises, so the valve should also work, no?

I'm still clueless :(
 

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Discussion Starter #7
Is it safe for me to bleed down the Accusump pressure (currently at 80 PSI) to 15 PSI, even when I'm not sure whether the Accusump is filled with oil ?

I would want to reset the pre-charge.
 

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I am so very grateful that you took this much time to write an extensive reply. Thank you!

I tried to measure the voltage on the pressure switch to see whether it would get any power. I hope, this IS the correct switch. See the photo below :



It shows that the switch is getting power, so it cannot be the switch not working, can it ?

If it's not the switch, then it might be the valve not working properly. However, when I start the engine, the Accusump pressure rises, so the valve should also work, no?

I'm still clueless :(
What is that green wire?

The 12v should come from the car than wire to either port on the pressure switch, then wire from the remainning port on the pressure switch to the n/c port of the electric valve, then wire the ground port on the electric switch to car ground.
 

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I am so very grateful that you took this much time to write an extensive reply. Thank you!

I tried to measure the voltage on the pressure switch to see whether it would get any power. I hope, this IS the correct switch. See the photo below :



It shows that the switch is getting power, so it cannot be the switch not working, can it ?

If it's not the switch, then it might be the valve not working properly. However, when I start the engine, the Accusump pressure rises, so the valve should also work, no?

I'm still clueless :(
Please post your detail wiring and oil line connection diagram.
 

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Is it safe for me to bleed down the Accusump pressure (currently at 80 PSI) to 15 PSI, even when I'm not sure whether the Accusump is filled with oil ?

I would want to reset the pre-charge.
Don't worry. It won't kill you engine or damage anything.
 

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Discussion Starter #11
Don't worry. It won't kill you engine or damage anything.
Ok, I have dropped the air pressure to 15 PSI. I have then started the engine, hoping that the pressure would raise to equal the engine oil pressure but the Accusump pressure stayed at 15 PSI. I have tried increasing the RPM while another helper watched the needle, but it didn't move.

Now I'm wondering, why I did notice that the pressure moved from 60 PSI to 80PSI earlier this morning?

Frustrated and puzzled!
 

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Discussion Starter #12
update:

I have managed to discharge the Accusump manually by joining the 2 wires from the pressure switch together (by-passing the switch). The valve is working and discharging the oil. The pressure switch is hence faulty, good call HKFEVER!

I have read that you had replaced the OEM switch with a heavy duty switch? Which one exactly, and how easy was the install?

Alternatively I'm thinking about removing the Accusump and using a baffled oil pan instead....
 

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update:

I have managed to discharge the Accusump manually by joining the 2 wires from the pressure switch together (by-passing the switch). The valve is working and discharging the oil. The pressure switch is hence faulty, good call HKFEVER!

I have read that you had replaced the OEM switch with a heavy duty switch? Which one exactly, and how easy was the install?

Alternatively I'm thinking about removing the Accusump and using a baffled oil pan instead....
That heavy duty digital pressure switch is a custom make Germany product, cost more than the accusump :(

So go for the oil pan and save some weight :)
 

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Discussion Starter #14
Here is a rather oversimplified view of how I "think" that the Accusump system is working, e.g. neither the increase nor the decrease in pressure are linear and both pressures aren't 100% in balance when rising (I guess once is lagging behind) as pictured above, but I think it gives a good idea of how the system works.... provided that my drawing is correct.

If it's faulty, please feel free to comment!

 

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Discussion Starter #15
btw does anyone know the part number of the pressure switch that comes with the Accusump system in a Lotus ? I figured I could order from GEMS directly.
 

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btw does anyone know the part number of the pressure switch that comes with the Accusump system in a Lotus ? I figured I could order from GEMS directly.
Louise @ Gems won't provide the parts number nor sell you the parts, I tried :mad: What you can do is fill out their custom made switch form but the catch is you need to order 10 or more. :D

Canton Racing's parts number 24-273K.

The attached JPG is the image of the most current pressure switch that use by Lotus and Canton Racing.
 

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Here is a rather oversimplified view of how I "think" that the Accusump system is working, e.g. neither the increase nor the decrease in pressure are linear and both pressures aren't 100% in balance when rising (I guess once is lagging behind) as pictured above, but I think it gives a good idea of how the system works.... provided that my drawing is correct.

If it's faulty, please feel free to comment!

When car is fully hot and idle, the oil pressure is between 24psi to 30psi.

The electric valve is always open one way, only goes in the accusump all the time. Unless the pressure switch close the circle, then the electric valve will become both ways.

The GEMS pressure is set to close circle at around 35-40psi, but in real life each switch is different, some is 37psi, some is 33psi....

So when the car is in idle, the accusump should be empty and the gauge should show the similar pressure as the idle oil pressure 24-30psi.

The operation of the accusump is like this:
1. Cold car, start engine, the oil pressure shoot up to 75-80psi, and the gauge show 75-80psi.
2. Fully warm up the car and oil, at idle oil pressure is around 24-30psi. Due to the pre-set pressure switch, the accusump should purge the oil at around 35-40psi. This happens during stop and go at red light or when your oil pump fail.
3. During normal driving, the oil pressure is around 45-60psi. So the valve is always close (only one way in no out), it means oil can only goes in the accusump but can't come out.
4. When you park and shout off the engine, the accusump will maintaine the same pressure when you turn off the key. So the best way is rev up the engine to have 45-60psi then turn off the key. Otherwise the accusump won't hold any oil for your next start up.
 

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Discussion Starter #18 (Edited)
I have just measured the voltage at the pressure switch and at the valve.



I have unplugged the cable at the pin/tab closest to the valve (circled in red on the pic above) and measured the voltage at the pin. It showed 12,3 Volt.

BUT, when I replug the cable back in the pin and measure the voltage through the cable shoe, it only showed 5,3 Volt.

Then I measured the voltage at the valve and it also showed only 5,3 Volt.

Is this all normal ? Because, when I bypass the pressure switch (when I join the 2 wires, the valve DOES open) and measure the voltage, it shows 12 V... it seems to me as if the valve is opening only at 12 V (bypassing the switch) but not at 5 V, but where are the missing 7 V going?
 

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Discussion Starter #20
I got to measure the voltage on a friend's CUP 260 pressure switch (cheers valain ) and it showed 13 V at each pin.

I guess this finally confirms it, my pressure switch is defective!

HKFEVER, a special thank-you for your much appreciated help! You have been right from the very beginning!! :bow:
 
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