Recently had to do the old oil rail pressure sensor replacement job on my Jack. I was a bit apprehensive tackling it without instructions, so thought I'd throw together a little how-to for anyone in the same boat.
First, the diagnosis. The issues started with a bit of spluttering, then she died completely (while out of town, of course). At this stage disconnecting the injector harness (bundle of pink wires at the back LHS of the engine) and cleaning out the leaked oil in the plug helped. Eventually the problem got worse, and the engine wouldn't start at all.
To confirm the issue lies with the ORPS, open circuit that sensor by cutting the white wire that plugs into the injector harness (circled
here). This will kick the ECU into limp mode, with a check engine light up and reduced engine power, but at least it will start and run reliably.
With the ORPS open circuited like this, the engine will need to crank for longer than usual before it will fire - extra glowing time helps here (keep glowing for a few seconds after the glow light on the dash has gone out). You can run indefinitely like this, just don't expect to get anywhere fast. Fuel consumption will be normal, or increased slightly due to the need to lean on the accelerator a bit harder all the time.
Eventually you'll get sick of being overtaken by Daihatsus and decide to fix the problem.
Parts required:
-Oil rail pressure sensor GM8971370421
-cable ties
-gasket goo
Parts desirable:
-Rocker cover gasket GM8971606721
-O-ring for the ORPS (only available from Holden with the complete oil rail)
-injector harness GM8971463368
-two O-rings for the high pressure oil line GM8971842160
-oil line to rocker cover seal
-oil and oil filters GM8971679720 and GM8972093062
I'll try and dig up some part numbers and post them tomorrow.
Tools required:
-a cheap 9/16" open end spanner (you'll need to grind it down)
-assorted sockets, pliers, etc
Tools desirable:
-gloves (there'll be lots of oil around, and lots of things to skin knuckles on)
-30?mm flare nut spanner for the high pressure oil line. A big shifter will suffice.
Procedure:
1. remove intercooler (plastic surround lifts off, then four bolts and two hose clamps for the intercooler itself), and intercooler bracket
2. remove airbox-turbo pipe
3. remove any PCV/breather/EGR/whatever plumbing that looks like it might be in the way
4. remove throttle body
5. remove plastic rocker cover cover (be careful, there might be more bolts than you immediately see).
6. remove foam insulation
7. remove the high pressure oil line that runs from under the manifold into the side of the rocker cover.
8. remove rocker cover
9. disconnect all the plugs of the injector harness and gently push it aside
10. halfway along the oil rail, you'll see a little brass sensor that looks like the new one you just bought. you can probably take the oil rail off, separate all the injectors and get the sensor out, but that was a can of worms i didn't want to open. Instead, grab your least favourite 9/16" open ender, grind some meat off its sides, and start lefty-loosying. The limited access means you can only do about 1/16 of a turn at a time, but you'll get it eventually.
11. Screw the new sensor in, preferably with a new O-ring
12. Reconnect all the plugs on the injector harness. If you like doing things properly (and throwing money at Holden), use a new harness. If not, reuse the old harness, and use cable ties to clamp any broken connectors.
13. Replace rocker cover, either with goo or a new gasket.
14. Put everything back how you found it.
15. solder up or crimp connectors onto that white wire you cut earlier.
16. Recheck that everything is done up.
17. Turn ignition on. No CEL - hooray!
18. Crank. Expect it to take a bit of extra cranking while it builds oil pressure again.
19. check for leaks.
20. Rejoice in your full 118kW.
The whole job took me a few hours, without rushing. Changing both oil filters afterwards was a more painful task.
some pics:
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One warning - there are stories that the ECU needs to be recalibrated to the new ORPS. This requires a Holden Tech-II computer. My vehicle runs fine with its new sensor, as have several others I've heard of. Your milage may vary.
Hope this helps.
Dane.
