I have a 1998/99 Isuzu Wizard with a 4JX1 Engine (3.2l Diesel) which has done 38,000kms (I have only had it for 6 months - we have done about 3,000kms).

About 2 weeks ago my wife was unable to start it and it was taken to a specialist in Turbo's and Diesels. Unfortunately at this moment in time they have been unable to fix the problem (it has been scanned by 3 companies gear, all of whom are the respective agents for Isuzu/Holden). That is why I have turned to this forum (for help please)!

They state the 4JX1 Engine is too advanced for their scanning tools and unless it has a fault light, then nothing will appear on the scanner.
Talking to them, they really don't have any ideas as to what is wrong...and they don't know of anyone else locally to send it to. They are at the point where they are going to just try things until it miraculously works. That may be the only option I have left, but I would prefer that it had some logical direction (as each experiment costs me and takes time).

I am hoping someone out there may have seen this fault before (especially from another country) and can give me somewhere to go with this (basically I have no avenues left to try)...other then their try it and see approach.

I did see a thread earlier that spoke of a "Random Dying Trooper"...it was an older model but seems similar to what I am speaking of (if it is a fuse thing, I just wasted time and money on something I could have fixed <img src="/forums/images/graemlins/frown.gif" alt="" />

If you have any ideas, the symptoms are below, if not thanks for reading this much and I hope your problems are resolved...

The symptoms of the problem are:

1. It started as an intermittent problem (only about 4 weeks ago) when we start the vehicle (Note: We had an alarm installed the day before this problem appeared, I felt it was something to do with this but even after removing the alarm it is still not going)?

The original problem was, it would start as normal but when I went to take off, the engine would lag, struggle and the car would crawl along (it had no power) but it continued to run, it didn't cut out. I would stop (engine still going), put it out of gear and rev, it would be fine, then take off again and it would struggle as before. I tried turning off the AC, Radio and all electrical devices in the car, it seemed to work (could be a coincidence) and then off it would go as if nothing happend.

Note: There wasn't any black or white smoke shooting out of the rear when power returned...it just went as normal

2. The day before we sent it in to the specialists, these symptoms appeared. I had just returned from a trip (2+ hours of driving) and decided to just pop to the local store. The car had been sitting for about 45 minutes. I got in and tried to start the car. The car would start and stop almost immediately after it reved (it was a gradual stop - sort of a splutter then stop). I tried restarting it and it did this a couple more times. I then tried it in Neutral, turned off all electrics and it eventually started. There was a smell of diesel but no smoke. I drove to the store, but when I tried starting it again, it did the same thing. When it eventually started, I drove home but it was running very sluggishly (possibly rough) and when I stopped, it choked to a halt. I didn't use it the rest of the day but told the wife to keep an eye out for it the next day.

3. The next day my wife tried to use it and it wouldn't start at all. Nothing she tried worked. We called a mobile technician, he came and guess what, it started. However, after a repeat of stoping and starting it eventually didn't go at all. Since then it has been in the workshop, moved from specialist to specialist and it still isn't going.

- The Alarm people came back and removed the alarm (it is no longer installed) - but it still doesn't start
- They have changed the oil (said it didn't have the right oil in it) didn't have any affect on this problem
- They changed the fuel flow valves to one way units (something to do with build up of fuel pressure), no affect on this problem

One of the specialists wants to send the EFI Valves away overseas for testing (is that a good idea - seems expensive and a reach in the dark to me)?

I have checked this forum and others for this problem. Unfortunately nothing is 100% the same but I have a short list of the problems closest to this issue (although the experts suggest that some are specific to older models, which have been fixed in the 4JX1 engine).

- Idle control Valve?
- Bad Fuel Pressure Regulator?
- Fuel Injector Oil Leak into Fuel/vice versa?
- Loose wire in fuel pump connection?
- Oil Gasget Leak or Blockage?
- Computer Issue?

Note: When starting this vehicle it seems to take longer then previous Isuzu's we have had (it takes about 4 to 6 seconds before firing up) but it always did start up before this happend...could the starter be faulty?

I had a similar issue with my Subaru Legacy which was fixed by replacing a sensor - don't know which one (something to do with the vehicle starting, not knowing it was running or thinking it was when it wasn't and would stop or wouldn't start)...could this be the problem and if yes, what/how would we know?

If anyone out there has any ideas, it would be appreciated.
Cheers in advance...

My initial guess is a fuel delivery problem.
Is the air cleaner clogged? (Based on the description I doubt it is)
Next, remove the fuel filler cap.
Then attempt to start. Is it possible that the vent on the cap is clogged and precluding the fuel from being draw from the tank.
Are all the fuel supply lines tight going into the filter, from the filter to the fuel injection pump tight?
Are the lines coming out of the pump going to the injectors tight?
ANY (even the slightest) leak will cause air to be sucked versus fuel delivered.
Is there a ground connection on the computer? If so check that it is clean and tight.

Eric

I would be gueesing a bad earth causing intermittient issues. When this kind of fault occurs suddenly it's often very usefull to think what has changed recently and that in your case is the alarm. You need to go over what the alarm people did with fine detail. Even if they removed it you need to hassle the guy who did it and check step by step what he did. Any joins they made or cut into should be checked, earths in particular.

Well my 2 cents worth.... good luck

I second the issue as being fuel related, possibly a fuel blockage/restriction of some sort. A fuel pressure test (if it's common rail....I'm not familiar with this engine, though the mention of a computer makes me think common rail) will verify if this is the case.
However, it seems more than slightly coincidental that the problems started after the alarm install. They may have removed the alarm, but may have caused a problem during the install, shorting a wire or whatever.
I know this is a rather vague answer, but as a mechanic, this is where I would look, based on the info you gave us.

Good luck, let us know if you find out more, or find the cause.

Also, welcome to the forum!

<img src="/forums/images/graemlins/cheers.gif" alt="" />

I spoke with Isuzu techs at the dealer regarding installing an aftermarket alarm, and they highly recommended against it. All kinds of problems with vehicles not starting/running right/intermittent running etc. after install. Most alarm installers tie into the existing factory system instead of a fresh install which would be in addition to and not instead of the factory alarm. And since the alarm is part of the on board computer now, all kinds of bad things may be possible even with the uninstall of the aftermarket alarm system.

You may not be aware but there is also a recall active on these engines. It may be an outside chance that this is your problem.

http://clubisuzu.proboards29.com/in...mp;action=display&num=1107592712

and

http://clubisuzu.proboards29.com/in...mp;action=display&num=1092207907

I have a 2000 Jackaroo (Trooper) with a 4jx1 motor.
These motors use a hydraulically powered electrically actuated injector system. Engine oil is used for this purpose.
The choice of oil is very critical to the operation of the motor and it has been found in the cooler climates that a 5W-30 oil is required.
The reason for the slower starting of the motor- like the six seconds you quote is due to need for the injector supply pump to build up pressure to adequately operate the injectors. The second filter on the LHS of the engine is for this pump.
The main reasons I have had or have heard for the engines not to start are
1 Dead or dying batteries (pretty obvious)
2 Leaky injector o'rings allowing gas or air into the fuel system. This is usually picked up by placing a piece of clear plastic hose into the fuel return line and looking for air bubbles. Most countries conducted a recall to fix this problem. In extreme cases I have heard that the oil can run into the cylinder through faulty seals/seats and cause engine run away and subsequent destruction.
3 Leaking mechanical fuel primer pump. I think there is an excellent description of this in the archives of this site.
But same deal, will allow air into fuel system and allow the fuel to flow back to the tank when engine is switched off.
4 loose or broken oil pick up/strainer for injector oil pump.
This happened to mine with about 38,000 km on the clock and took the local dealership a month to find it and repair. In my case it was only loose but I have heard of them breaking off. The sump pan needs to be removed to check for this.
I hope that these ideas may help your mechanics solve your problems

Regards Craig
In regards to the fuse thing ....If you blow the brake light fuse the car won't start either. I know a person who had their truck towed for 1000km to the nearest dealer to find out that he had just blown a brake fuse.
There is a fault light but you need to find which pins to short on the harness connector which is located somewhere in the dash behind the radio or ash tray
The number of times the malfunction indicator light flashes gives the identification of the fault. A search on the internet may help you find the codes.

I just want to re-interate something that has already been pointed out, but can't be overstated. The fuel circuit on the 4JX1 is an advanced high-presure system. The enjine won't kickover until the fuel system is up to pressure...you need to wait a few seconds at ignition-on before you crank it, and then crank continuously for the 3-4 (4-5-6)seconds that it takes for the engine to start. The worst thing to do with this engine is to flick through ignition-on without waiting, then stop the key-turn 1-2-3 seconds in because it doesn't kick-over (like you might in gasoline/petrol powered vehicle).

Isuzu suffered for this quirk, with as many user claims as there are vehicles on the road.

The hard start (as has been mentioned already) is sometimes worse with out-of-spec oil, or oil that is old and tired. Engine oil flows through the diesel pump itself (around those very tight nooks and crannies surrounding the injectors, too) and makes a huge difference. Users in hot climates are sometimes tempted to use 15-40 or 20-50 weight oils and create problems at cold start. In diesels, most wear and tear occurs at cold start.

Your problem may be related to the way you crank over the engine. The short spurt type crank I mentioned above has been reported to damage the pump. A fatigue problem.

Or, it may be directly related to the alarm install. The entire fuel circuit is a maze of electronic sensors and relays fed directly to the ECM. The injectors, too, are directly plugged into the ECM. Any electronic problems will effect the engine directly. Any shorts, any loose grounds...

As an aside, there are no aftermarket alarm makers (or remote engine-starter makers) in Japan that make a harness for the 4JX1. It's factory or nothing. Or, it's a special order from someone who knows the 4JX1 well enough. Even then, remote-starters don't last. Even if they can be programmed for the delayed-start, they end up not coping with the continuous cranking.


--Bighorn--

Hi, Newbie here. I have just purchased a 1998 wizard ex Japan.

About the delay in the engine starting, most electronicly controled diesels now will not fire up until a minumum oil pressure is reached, hence the delay, and, as mentioned,a minimum preasure is reached in the fuel rail.

I am also a fully qualified heavy equipment mechanic but am not very familier with common rail engines.

I have worked on a lot of Trucks, Tractors and earth moving gear that are computor controlled and fitting anything electrical that is not approved for that vehicle is asking for a lot of <img src="/forums/images/graemlins/scared.gif" alt="" />.

I would say that alarm system has done something with the fuel control software but its also worth having a very carefull check of the earth points around the motor, chassis and battery. Computor control systems a very, very fussy about having a good earth and all sorts of weid and crazy symptons can arise with a bad earth.

Good luck

Please could you advise me if you found the problem reported on your Isuzu Wizard (Toiboy starting issues)and if so how did you correct the proble. I have just imported a unit from Japan which has the exat same problem
Please advise.
Thanks and regards,
Roy Sinclair.