4JX1 - Starting Problem

just a thought have you checked air filter and others???

Hi All

Well since my initial post I now know a “little” more about the 4JX1 engine. I am still very impressed with it even though the injection system is very technical.

I have spent days on the web and killed off a couple of forests in the process.

From the mechanic reading what I printed, and his own knowledge it came down to being more than likely (80%) the Oil Pressure Sensor (part no H8971370421) on the oil pressure rail. This sensor does not give an error when faulty which we found out from one of the forums.

Before it came down to the sensor the mechanic had, through normal fault testing had thought he had done something and had fixed the engine including cleaning some sensor connectors. He also put a gel in to the connectors to stop any future moisture, corrosion etc getting in. So after running perfectly for 2 days when I went to pick it up the engines started, ran roughly, stalled within a minute and refused to restart. He was pissed.

This is what was done to the engine - Checked fuel flows & fuel aeration by fitting gauges to the fuel & oil rails, Pressure test, Checked engine sensors, Checked computer fault codes (none found) as well as a new battery, changed oil and all filters (oil x2, fuel, & air). To replace the oil pressure sensor they had to remove the rocker cover, common oil rail and injectors, so the O-rings were replaced again. Plus the wagon had a normal service.

So now much relief all round. I think he, the mechanic, was glad to see the back of me. And you might ask about the cost, well I think I will be eating vegemite sandwiches morning, noon, and night for the next few months. Well not that bad.

Driving around for the last few days I think the engine is smoother and a little quieter but still has as much grunt as before. So I hope this is the end of it.

The mechanic has worked on quite a few 4JX1 engines but, he admits it himself, is still learning as there is not a lot of official information out there. I think he is the closest thing we have to an expert on these engines. He has even gone to Caterpillar to learn how the common rail/injectors system works. Caterpillar designed this injector system. His name is Geoff and he works at Clayton Auto & Truck in East Tamaki, ph 09 274 7737. I know the phone number off by heart.

I found a couple of forums which helped me and the mechanic a lot.

Isuzu Trooper Owners Club (UK)
www.itocuk.co.uk/forums/

Jackaroo/Frontera/Rodeo Owners Australia
forum.australia4wd.com/index.php?showforum=18

These sites have lots of stuff about the 3lt engine from other 4JX1 owners, some great, and some real rubbish. Not as much about the 3.1 or 2.8 engines. Not that the 4JX1 is more problematic as I read some scary stuff about the 3.1. I guess it comes down to richer countries that can afford to replace their vehicles sooner.

If you think we don’t have much time for Holden you should read what the Ozzies have to say. A lot comes down to very poor support as the Holden mechanics have not been trained on these engines. In the UK, the pomes have better comments about the Isuzu franchise their but it still comes down to poor knowledge.

Also the pommy Isuzu franchise didn’t consider the O-ring fault a major recall and carried out the work as part of normal servicing. When the fault was first found there was concern from owners but the local franchise stumped up, sent out letters and carried out the work.

Why do I type such long posts?

Thank you to the people who replied to my post.

Cheers
Craig

This is a few things I found
1. the second, smaller oil filter should be changed every 20,000k
2. The timing belt is long life, every 200,000ks. I don't know if I would risk it. Also there is no light on the dash which indicates it is time to change belt.
3. there are 3 oil pumps, 1 each for the oil filters and a 3rd to get the oil pressure up to the injectors.
4. the oil pressure for the injectors, the manual says 2,000psi but in practice from somewhere over 1,000psi
And so on