Why the 4JX1 Breaks Down and Why You Shouldn't Worry

[@irineodeleon6758]

Hi , Sir i'm from the Philippines i have an issue w/ my trooper 4jx1, it could not build a high pressure from (HPOP) high pressure oil pump so the engine doesnt start. Sir i am asking a favor from you to help me with my problem. Thank You Very Much .

[@thejackaroo4WDcampingchannel]

Hi, do you have access to a Tech 2? If you think the HPOP is faulty, then you'll need to change it. However, you need to use the correct oil in the engine or it won't work. In the Philippines, you must use 5W-30 Oil only. If you have any other oil in the engine, then drain it and put 5W-30 in there. Furthermore, I would check the RPCV function, this regulates the High-Pressure oil and if it is stuck, it can cause issues. Do not replace it with a Cheap Chinese RPCV, it will fail. The other component is the ORPS which sends the oil rail pressure to the ECU which in turn controls the pressure via the RPCV. RPCV is the Rail Pressure Control Valve. ORPS is Oil Rail Pressure Sensor. Moreover, check your high-pressure oil pipe for leaks and check that the Oil Rail isn't leaking at the ends. I hope this helps.

[@pkgoldopalhunting]

hi hope you can help did new exhaust manifold gasket flange gasket and fit new turbo and it is idling rough i cleaned out injector harness have you got any ideas please video of it running ,, kzbin.info/www/bejne/goq7hKeMotygjJI

[@thejackaroo4WDcampingchannel]

I might be able to help but I can't view the video as it is private

[@thejackaroo4WDcampingchannel]

What did you do, was it like this before or just after? The turbo and exhaust likely wouldn't cause a misfire, more likely, have you touched the injector harness inside? Are you certain that your injector harness plug is connected correctly? Have you checked the ECU plugs for oil ingress?

[@clementmbaso2273]

Powerful education from this video on 4jx1 engine

[@simoncunningham3740]

About to buy a 98 bighorn(trooper to most i think) and I got somewhat concerned when I found out it had a 4jx1 but Im feeling much better about it now. Many thanks!

[@thejackaroo4WDcampingchannel]

I'm always here to help, also consider joining the FB Group - 4JX1 - decompile / learning project. facebook.com/groups/264658247280734

[@simoncunningham3740]

@@thejackaroo4WDcampingchannel I will do thanks!

[@roybatty2030]

Thanks, great video. Had one of these for 13 years with very few issues. Replaced the ORPS twice and the clutch retainer clip snapped once but otherwise very few issues, a great car.

[@MiniLuv-1984]

Wow, Dave, the guru of HEUI!! Very informative, thanks. I see autobahn has 5L Penrite HPR 5 5W-40 (Full Synthetic) - HPR05005 for $55 at the moment.

[@thejackaroo4WDcampingchannel]

Yes, I bought some last week ready for my next service before our trip to SA.

[@blakyut1956]

Thanks for the video, very informative, I fear giving my bighorn/trooper to mechanics after a bad experience with them, I now work on it on my own and it's been running well, I just stumbled on your channel while doing more research on this engine and I can say your explanation was very helpful

[@thejackaroo4WDcampingchannel]

Thank you for your kind words, that is precisely why I made this channel, to help people that cannot find mechanics who know anything about HEUI engines. I'm not sure where you are located but here in Australia, many mechanics have given the Trooper a death sentence because of a damaged head and in reality, it is injector seals that are the issue, not the head. I would like to mention that I have put numerous documents on the Patreon channel, including the Trooper Manual from Isuzu. You can find it here: patreon.com/user?u=15041170 Furthermore, consider joining this FB group for great help and advice - 4JX1 - decompile / learning project Thanks

[@brizaheandog2186]

What a Great Video, Thanks so much for your insight.

[@jasonmorrisby169]

Is there anyone in Queensland that fully understands these Engines.

[@thejackaroo4WDcampingchannel]

Of course there is, I would suggest looking at some Facebook groups to find someone. What specifically were you wanting to know?

[@thesiuslee189]

Thank you for your video it's very helpful

[@garynew9637]

4jx and simple is an oxymoron.

[@DavidNotSolomon]

That is great video - fortunately I have a 1986 Jackaroo with the 2.3 litre petrol engine, which most mechanics over 40 will quite capable of working on without too much trouble.

[@thejackaroo4WDcampingchannel]

Yes, it's just the HEUI engine they struggle with.

[@garynew9637]

Could oil in the harness cause a no start, mine was getting harder andharder to start. Towed it for 15k in 4 th gear and it started. Got me home but never started since.

[@thejackaroo4WDcampingchannel]

Yes it could, the reason I suggest checking this first is that this is easy and an easy fix.

[@garynew9637]

Did the white wire thing, no start. Going back to basics. Blowing compressed air through the fuel line back to the tank. Don't have a cel. So I ll start there. Cheers.

[@thefunkishere]

Thanks again for all your effort! Was wondering if you had a video detailing the replacing of the ORPS, I’ve just bought a 2002 jackaroo and the previously owner believes the spluttering idle is from the ORPS. Says he has replaced it before. Would love to learn more about this vehicle and dive in the the diy fixing. Cheers

[@thejackaroo4WDcampingchannel]

I haven't done a video on the ORPS because I hadn't started the channel when I did mine. I can elaborate on the ORPS though and give you some tips. The ORPS or Oil Rail Pressure Sensor lives under the rocker cover and is attached to the Oil Rail where it monitors the pressure of the rail oil and sends it to the ECU. The ECU sends instructions to the RPCV or Rail Pressure Control Valve to change pressure in the oil rail. That is a basic HEUI explanation. You can see how the ORPS is doing on the Tech 2 but, before you change the ORPS, I would look at the injector harness first because this is an easy check to do. Because your engine is spluttering, it could be the injector harness oil issue. Watch this video to see if it helps kzbin.info/www/bejne/mYDbZqV9lq9gZ7s Basically, oil using capillary action comes along the wires to the injector harness plug where it interferes with the signals to the injectors. Clean it out with electrical contact cleaner and see if that helps. If it doesn't, then you might try cleaning out the RPCV which is on this video here: kzbin.info/www/bejne/j4aVdWl9h9poZ7c Both of these can be done at no expense, if they don't work, then an ORPS might be on the cards, but don't buy an eBay ORPS, they are garbage. You need to get an Isuzu OEM ORPS, possibly from Ibrahim in Dubai. If you do end up changing the ORPS, you'll need to modify a spanner to remove it, you can see that here: kzbin.info/www/bejne/mH_Zoquqhb2sgas Be very careful with the rocker cover bolts, when you refit them, they will strip the threads if you sneeze at the wrong time. Furthermore, make sure you use RTV on the half moon plugs at the back of the rocker and at the corners at the bottom of the domes. We use Permatex, The Right Stuff and it works very well. I'm here to help, you can email me if it helps and you need additional information. I can also send you an Isuzu Trooper Tech Manual. You do know that the Holden Jackaroo is an Isuzu Trooper, right. Here's some Tech 2 data: Rail Oil Pressure Engine MPa 3.5 ~ 5 at idle 4.5 ~ 10 at 2500 rpm General Description DTC P0192, P0193 Desired Rail Oil Pressure Engine MPa 4 ~ 5 at idle 5 ~ 9 at 2500 rpm General Description DTC P0192, P0193

[@thefunkishere]

@@thejackaroo4WDcampingchannel thanks for the detailed reply, honestly there should be more people like you in the world! The guy who sold the car actually had a spar ORPS. I will certainly check the things you stated before diving in. He also gave me the spanner he modified. The injector harness sure has way too much oil built up on it. The vent hose from the engine that supposed to feed back into the air intake has detached, the engine is a bit of a mess since he has left that hose hanging. Still trying to figure out how to reattach as the in-line connector thing on the intake is missing. I saw your video for the catcher might be worth the start. For now I’ve just taped up the hole in the intake where the tube is supposed to live. What is your email I would love to keep the convo going down the line. And that manual is a brilliant idea. I have been hunting but just mainly finding spam. Your videos have reassured me that I have made the right decision buying this car!!

[@thejackaroo4WDcampingchannel]

I've never tried an ORPS from eBay but it is banded about the Jackaroo owners that the only definite with a eBay ORPS is a breakdown at the side of the road. The issue with ordering from Dubai is the postage costs, I tried doing a deal with them but got no reply. Unfortunately, Isuzu and GM did a deal where Isuzu would not supply parts to Holden owners. Even though GM has now gone, Isuzu dealers know nothing and won't even try to obtain parts. This is why we go to Dubai. If it were me, I would be asking on the FB group if anyone has a spare.

[@thefunkishere]

@@thejackaroo4WDcampingchannel I will check and see if the part is OEM or not. Apparently he only put one in 2 years ago so he could have gotten a lower quality part.

[@thejackaroo4WDcampingchannel]

@@thefunkishere Great that you have the spanner. If the injector harness is oily, then that might be the issue as it interferes with signals from the ECU to the injectors. Okay, the vent hose is the crankcase breather from the engine that runs back into the intake pipe. He may have removed it or it may have blown off. The engine is direct injection so my advice would be to fit a catch can, video right here: kzbin.info/www/bejne/anaoq6Kvq89rd5Y But, before any of that, remove the pipe from the air box to the turbo inlet and look for oil in the turbo air intake. You can see into the turbo in this video here: kzbin.info/www/bejne/n57HoJSoadmSpLc That might be why he removed the pipe.

[@jack46476]

Nice info

[@thejackaroo4WDcampingchannel]

Thank you for your support