Isuzu Trooper Owners Club UK™

[Xeffin1]

Check out what these guys have done....

http://forum.australia4wd.com/index.php?/topic/25283-oil-rail-pressure-sensor-valve-rebuilding-for-4jx1-engine/

[Google]

[Browndoff]

Thanks Xeffin - That was an interesting link to that Aussie post. One must exercise caution, though, in taking advice from someone who clearly doesn't understand how the ORPCV [he calls it the ORPS!] actually works!

I think folks SHOULD try to clean and fix these expensive parts - but NOT to fill them with anything other than clean engine-oil - 'cos they are SUPPOSED to operate with this as their hydraulic-fluid.

The ECM is informed of the current oil-pressure in the Injector-System by the Oil-Rail-Pressure-Sensor, it compares it to what's required by the current Throttle-setting and sends a proportionate signal to the Solenoid. The solenoid moves the flying piston magnetically, which pushes or pulls the large pin, which pushes or pulls the small, pointed pin , which opens or closes the tiny orifice in the back of the main  valve – which then hydraulically closes or opens the main HP-Oil Valve in the 'trumpet'-end of the ROPCV.  This controls the variable-pressure of oil used to control the fuel-injection.

BTW      The O-rings at the 'trumpet'-end are vital in separating the constant HP-Oil from the Pump from the VARIABLE-Pressure Oil going to the Injectors - so they must be replaced, if damaged.

[Xeffin1]

Thanks for that explanation, i wondered how it did what it did, it seems a very complex way of doing things, i had no idea the solenoid acted proportionately in response to the throttle body.

I have cleaned mine and have discovered that there are 2 seals at the trumpet end one a green round O ring and another flat black band which sits behind it, the flat black one has split, can these be bought separately??

[Browndoff]

By an odd coincidence [I took it out to try in another engine], I found out mine has the same split plastic O-ring - but it was functioning perfectly and it did, too, in the car in which it was used for a test.

I think the 'trumpet'-end should unscrew from the end of the main-valve - but I failed to shift mine - even with a pin through the cross-holes. This bit would HAVE to be removed to replace the plastic O-ring, though the rubber O-ring would be able to slip on over the end. If you DID manage to remove the 'trumpet'-end, than you could remove the valve itself and the return-spring and clean them, too. I wish I could!

" it seems a very complex way of doing things"            I couldn't agree more - but THAT'S the Isuzu way!!

[Xeffin1]

I will see if i can manage it tomorrow, i unscrewed the fluted bit by trapping it in a vice between 2 pieces of wood i took care not to do it too tight didnt want to distort the fluted bit.

I took the seals off to have a look and couldnt detect a join, could be my eyes not able to see it though lol

[Xeffin1]

Just noticed on the post below mine re ORPCV I think they are Gribbles pics show his black band is split diagonally exactly like mine. must be a manufacturing fault and maybe does not mean much so long as the green O ring is intact.

[Gribble]

Just an comment or two here for Technical accuracy .

Split plastic O ring - thats a high pressure back up seal it only fits one way , did you check that ? They are made like that split with a 45% taper .

But your an time served man on Hydraulics of course so your next post was -

BTW      The O-rings at the 'trumpet'-end are vital in separating the constant HP-Oil from the Pump from the VARIABLE-Pressure Oil going to the Injectors - so they must be replaced, if damaged.


Thats  wrong and misleading Browndoff .Its a Forum -  yes so the people reading it look and think but that ,well words fail me .

Oh do post how a swash plate type  hydraulic pump works ,is that what a 3.0 trooper has ? Or is it a Fixed Displacement Bent Axis  one   ? Nope the Trooper has neither .



Post something useful . All you do is cover old ground like its some new DISCOVERY that nobody on HERE has ever worked out  .
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2 New Troopers !

[Gribble]

Its a closed center Hydraulic system - Oh , you didn't know that ?

Like the Hand controls in most excavators .
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2 New Troopers !

[eithan h]

and breathe lol

[kennymac]

 
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If all else fails just nod, smile and say "Yes Dear"

[Browndoff]

I'm sorry, Gribble for my foolish presumption! You ARE right!

I threw in my tuppence-worth to stimulate ideas on cleaning and fixing these valves - if possible - rather than having to buy new from Isuzu. The guy on the Aussie site was recommending stuffing the ROPCV with Moly-grease - which, I thought, would prevent the oil from moving through it properly....?

Would you, please, post a more complete explanation of how the HPOP and the ROPCV are supposed to work together - I really WOULD like to learn more!

[Gribble]

Might , might not .  

Probably will ,have to ask Robbo first though  
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2 New Troopers !

[kennymac]

[Xeffin1]

Well... Cleaned the ORPCV a fair bit of sticky gunk washed out immediately turning the petrol i used to wash black with some gritty stuff at the bottom of the tub, i took the valve apart except for the fluted bit with the piston, i cleaned and flushed it until it was all bright and shiny, the fluted bit i kept forcing petrol through the holes using a syringe with a blunt needle on the end used for filling inkjet cartridges, i kept working the piston all the time while immersed in the petrol it started to squirt the petrol out of the small hole where the needle valve sits (The bit thats broke on Gribbles pic) I also noticed there are 2 holes on top of the piston one leads directly to the needle valve the other seems to do not a lot.
The next bit was to buy 5 litres of 5w30 oil which i did, using the syringe i filled the tube with oil and dropped the pistons in (In correct order) added as much oil as i could to the fluted bit again working the piston to pull the oil through this helped tp lock the needle valve in place while i screwed the fluted bit back to the main body and re installed it back into the trooper. ( It still didn't start, what a rat) I have emailed Trooper Dan as i am puzzled as to whats not letting it start. Oh, forgot changed the oil just in case the previous owner did't use the correct oil.

[Red Robbo]