Volvo ec27d Revs

[JerryRtilt]

Think i need to watch what the cylinder does as the machine is stopped ?

 

[JerryRtilt]

Hmm ... it's getting an electrical surge/signal, when you turn it off, which bumps up the revs then, maybe, .... or.... it's sensing a servo pressure activation from somewhere ???

My Hydrema's system was something similar, but way more complex with 4 preset rev. setting selections .... had to bin it off and go to a manual throttle when it decided to give me grief

Its not really a problem, it just bugs me as when it works correctly its very convenient.

 

[V8Druid]

Its not really a problem, it just bugs me as when it works correctly its very convenient.

yeh ... bloody annoying, something like that

 

[Mick-the-fitter]

yeh agreed ... must dump the oil in 12 in B

does auto idle automatically engage when you start the m/c and you have to turn it off if you don't wish to use it ? if that is the case then the valve 2 in A may just be a set volume of oil (not prop.) and that volume is dumped everytime it disengages ... the variation is purely mechanical on the initial throttle lever setting ... sticking my neck out further, if that is the case a spike from the alternator when the ign. sw. is turned off could result in 2 in A pressurising 12 in B ????? have seen some alternators have a capacitor fitted to 'dump' any run on spike to earth

Yeah I get what you are saying there!

 

[sfrs4]

See if this helps any gentlemen.

 

[V8Druid]

See if this helps any gentlemen.

interesting ... seems to have a load sensing hydraulic system so it's not the servo circuit actuating/activating the auto idle, but true LS.
does the machine have a Variable Displacement pump @JerryRtilt ?

 

[sfrs4]

does the machine have a Variable Displacement pump

Yep
Pump specification Type Variable axial piston pump
Weight 16.5 kg (36.38 lb)
Displacement 28 cm3 (1.70 in3)
FR flow compensator, setting pressure 16 ±1 bar (232 ±14.5 psi)
DR pressure regulator, setting pressure 280 ±5 bar (4061 ±72.52 psi)
Max. torque 54 Nm (39.8 lbf ft)
Power control (engine speed 2350 rpm) Flow quantity at 118 bar (1711.4 psi) 50 ±2 l/min (13.74 ±0.53 US gal/min)
Flow quantity at 209 bar (3031.3 psi) 27 ±2 l/min (7.13 ±0.53 US gal/min)

 

[CPS]

OK so that makes sense to my theory,

So the way I see it is this, the solenoid on the valve gets power to open when auto idle is activated. This then sends oil to the cylinder which pushes the rack on the pump to idle.
When you turn the ignition off the idle solenoid then loses power causing the pump to go back to full rev before the stop solenoid has switch of the fuel system.

Not sure why it does it sometimes and nit others but my only thoughts would be to throttle down before switching off

 

[Mick-the-fitter]

OK so that makes sense to my theory,

So the way I see it is this, the solenoid on the valve gets power to open when auto idle is activated. This then sends oil to the cylinder which pushes the rack on the pump to idle.
When you turn the ignition off the idle solenoid then loses power causing the pump to go back to full rev before the stop solenoid has switch of the fuel system.

Not sure why it does it sometimes and nit others but my only thoughts would be to throttle down before switching off

Or there is a timer relay on the LS

 

[JerryRtilt]

Yep
Pump specification Type Variable axial piston pump
Weight 16.5 kg (36.38 lb)
Displacement 28 cm3 (1.70 in3)
FR flow compensator, setting pressure 16 ±1 bar (232 ±14.5 psi)
DR pressure regulator, setting pressure 280 ±5 bar (4061 ±72.52 psi)
Max. torque 54 Nm (39.8 lbf ft)
Power control (engine speed 2350 rpm) Flow quantity at 118 bar (1711.4 psi) 50 ±2 l/min (13.74 ±0.53 US gal/min)
Flow quantity at 209 bar (3031.3 psi) 27 ±2 l/min (7.13 ±0.53 US gal/min)

Thank you that's fantastic information, just out of interest does the ECR25d use the same pump ? i had one before the 27 and never been sure as the spec. sheets are not very clear but the 27 operates very differently ?

 

[JerryRtilt]

OK so that makes sense to my theory,

So the way I see it is this, the solenoid on the valve gets power to open when auto idle is activated. This then sends oil to the cylinder which pushes the rack on the pump to idle.
When you turn the ignition off the idle solenoid then loses power causing the pump to go back to full rev before the stop solenoid has switch of the fuel system.

Not sure why it does it sometimes and nit others but my only thoughts would be to throttle down before switching off

So if I'm understanding this correctly, the idle cylinder is briefly overriding the stop solenoid, to explain why it worked correctly when new and still does randomly, is it possible the stop solenoid has become lazy/deteriorated in some way ? its tempting to replace it ? Now we understand how the system should work, I'm just curious to figure out what's changed to stop it working as it should ? Or i could just push the throttle lever to the idle position as you say

 

[sfrs4]

Thank you that's fantastic information, just out of interest does the ECR25d use the same pump ? i had one before the 27 and never been sure as the spec. sheets are not very clear but the 27 operates very differently ?

All I can say for sure is they are different part numbers, the 27's pump has a slightly higer displacement 25cm3 v's 28cm3

 

[JerryRtilt]

All I can say for sure is they are different part numbers, the 27's pump has a slightly higer displacement 25cm3 v's 28cm3

That’s what I thought, thanks for your help.

 

[JerryRtilt]

So if I'm understanding this correctly, the idle cylinder is briefly overriding the stop solenoid, to explain why it worked correctly when new and still does randomly, is it possible the stop solenoid has become lazy/deteriorated in some way ? its tempting to replace it ? Now we understand how the system should work, I'm just curious to figure out what's changed to stop it working as it should ? Or i could just push the throttle lever to the idle position as you say

OK so that makes sense to my theory,

So the way I see it is this, the solenoid on the valve gets power to open when auto idle is activated. This then sends oil to the cylinder which pushes the rack on the pump to idle.
When you turn the ignition off the idle solenoid then loses power causing the pump to go back to full rev before the stop solenoid has switch of the fuel system.

Not sure why it does it sometimes and nit others but my only thoughts would be to throttle down before switching off

Yesterday i took the connector of the stop solenoid and gave it a shot of switch cleaner, plugged it back in and the machine stopped normally at idle for the rest of the day, about four times, maybe just a coincidence,? not using it today.
My thinking being the solenoid has become Lazy for some reason and the Idle cylinder is briefly overcoming it causing the revs to increase before it can shout of the fuel. Or it maybe another red herring Not sure of the inner workings of the pump to know if this is possible but it would explain why it worked correctly when new.

 

[V8Druid]

Yesterday i took the connector of the stop solenoid and gave it a shot of switch cleaner, plugged it back in and the machine stopped normally at idle for the rest of the day, about four times, maybe just a coincidence,? not using it today.
My thinking being the solenoid has become Lazy for some reason and the Idle cylinder is briefly overcoming it causing the revs to increase before it can shout of the fuel. Or it maybe another red herring Not sure of the inner workings of the pump to know if this is possible but it would explain why it worked correctly when new.

or the contacts in the connection are taking a brief moment to overcome any corrosion before making a circuit

 

[JerryRtilt]

or the contacts in the connection are taking a brief moment to overcome any corrosion before making a circuit

yes that's what i was thinking, its a descent sealed plug but wasn't a very tight fit, the machines less than 18 months old so would of hoped it wasn't to corroded, will have a better look at it next week see if i could tighten it up.

 

[JerryRtilt]

Time to update this rather tedious thread, cleaning the connections to the stop solenoid only prevented the revs increasing when stopping the machine with auto idle engaged briefly, i had got in the habit of shutting the throttle down manually before stopping but it still didn't stop cleanly and still sounded as if it was trying to increase the revs. About two weeks ago i realised it was stopping cleanly and has done consistently ever since even with the throttle lever set at working speed, as it did when new.?
The only thing that's changed is for about the last 4 weeks I've been running both machines on GTL diesel. The only explanation i can come up with is that the GTL has cleaned up the inner workings of the injector pump and the stop solenoid has less resistance and shuts the rack fractionally quicker, just my theory ?

 

[Shovelhands]

Time to update this rather tedious thread, cleaning the connections to the stop solenoid only prevented the revs increasing when stopping the machine with auto idle engaged briefly, i had got in the habit of shutting the throttle down manually before stopping but it still didn't stop cleanly and still sounded as if it was trying to increase the revs. About two weeks ago i realised it was stopping cleanly and has done consistently ever since even with the throttle lever set at working speed, as it did when new.?
The only thing that's changed is for about the last 4 weeks I've been running both machines on GTL diesel. The only explanation i can come up with is that the GTL has cleaned up the inner workings of the injector pump and the stop solenoid has less resistance and shuts the rack fractionally quicker, just my theory ?

I’m convinced that I “fixed” a vehicle by running it on GTL, so I’m not surprised by your theory

 

[JerryRtilt]

I’m convinced that I “fixed” a vehicle by running it on GTL, so I’m not surprised by your theory

Both my machines definitely run slightly quieter and somehow sweeter on it, had been wanting to try it for a while and pleased i did, when you actually look at the standard muck you can see its not going to go through filters easily.

 

[V8Druid]

Both my machines definitely run slightly quieter and somehow sweeter on it, had been wanting to try it for a while and pleased i did, when you actually look at the standard muck you can see its not going to go through filters easily.

Time to update this rather tedious thread, cleaning the connections to the stop solenoid only prevented the revs increasing when stopping the machine with auto idle engaged briefly, i had got in the habit of shutting the throttle down manually before stopping but it still didn't stop cleanly and still sounded as if it was trying to increase the revs. About two weeks ago i realised it was stopping cleanly and has done consistently ever since even with the throttle lever set at working speed, as it did when new.?
The only thing that's changed is for about the last 4 weeks I've been running both machines on GTL diesel. The only explanation i can come up with is that the GTL has cleaned up the inner workings of the injector pump and the stop solenoid has less resistance and shuts the rack fractionally quicker, just my theory ?

I’m convinced that I “fixed” a vehicle by running it on GTL, so I’m not surprised by your theory

very interesting commentary on fuel guys .... looks like we're all being fobbed off with semi refined crap then