Problem with Fuso in China

Andrew123

New member
G`day Andrew
What engine is in your truck? If you need a good FUSO contact in Mongolia we can help.

Hello,
My truck is sitting next to 2 Earthcruisers at MSM in Ulaanbaatar. Is that where you were going to suggest? So far I've found MSM very average to deal with and have very little knowledge of the FG84.
 

Andrew123

New member
Again sorry for the late response.
I made it to Mongolia. I got 120kms short of Ulaanbaatar and my 'new' radiator I got in Laos developed another crack, (for the 3rd time). me and a couple of locals took it out and put the old one in, (which no longer fitted). We tied it in with wire in true bush mechanic style and I got to Ulaanbaatar. That is just a side story.

I still have the problem with the engine popping and cracking. The truck is at the MSM workshop, which is a Fuso dealer. They are supposed to be the best around, but it frustrates me that they seem to know nothing about the FG series, even though I know others with FG's who have been there before me. There are 2 Earthcruisers, (also Fuso Canter) sitting next to my vehicle, though their engines have no electronics.
We finally got a computer onto my truck today. The current error code is P0192 (CRS pressure sensor (low)). The other codes are:
P1572, Sensor supply voltage 3
P0381 Glow plug lamp
P1335 Speed and position sensor
P1255 and P0335 Common rail pressure M/V 1
P0251 Common rail pressure defect

From that, the obvious thing is the common rail pressure sensor. I still think there will be issues even if the pressure sensor is replaced as the issue seems more complicated than that. Just to go over the issues:
-The engine is sporadically making a popping and cracking sound which makes it backfire and is assumed to be the engine misfiring, (the injectors have all ready been replaced and the fuel filter was changed only 3000kms ago). The air filter has also been replaced.
-The yellow check engine light is on.
-I can't go more than 2000rpm.

I have been trying to locate the common rail pressure sensor, (the mechanic too) in the service manual, but neither of us could find it. Is anyone able to assist? It is a 2008 FG84.
I'm not sure if the computer has limited me to 2000rpm or if it is some other issue. I assume it isn't safe mode as I can still reach 85km/h.

From all the information above, does anyone have any ideas?

A new starter motor should arrive early next week, but that was an earlier issue.

Thanks very much for all your help and advice so far.
 

pugslyyy

Expedition Vehicle Engineer Guy
On my 2007 FG...

My truck has been giving the P1335 error for as long as I have owned it, with no discernible effect.

I wrestled with low fuel pressure due to bad/contaminated fuel for a while so have some experience.

2000 rpm is the computer limiting the truck (it's in "limp mode"), which low fuel pressure can certainly trigger.

I've found that the low fuel pressure fault will self clear when the problem is corrected, so if you are still getting the code it is probably still an issue.

Untitled.jpg
 

gait

Explorer
a bit of a rough journey ...... !

Clear all faults, take it for a drive, read again. Fault codes may be "old" or "current". Only change one thing at a time.

Fuel. Either a real problem or a sensor problem.

Check the water separator and replace the fuel filter (yes, again, really). Clear codes take for drive. Read codes even if it runs well.

If still a problem check the volts to the common rail pressure sensor. There are no independent tests of that sensor operation in the manual.

Speed and position fault seems to happen when there are other problems ignore until last.

Read previous post about the blink codes so you are not reliant on Mitsu compouter in future.

Replace the glow plug lamp just to get rid of the code.

Please tell us what engine you have. FG84 describes the chassis. Then obtain an electronic copy of the engine manual.
 
Last edited:

Andrew123

New member
On my 2007 FG...

My truck has been giving the P1335 error for as long as I have owned it, with no discernible effect.

I wrestled with low fuel pressure due to bad/contaminated fuel for a while so have some experience.

2000 rpm is the computer limiting the truck (it's in "limp mode"), which low fuel pressure can certainly trigger.

I've found that the low fuel pressure fault will self clear when the problem is corrected, so if you are still getting the code it is probably still an issue.

View attachment 252183


The misfiring is what I'm worried about. I'm no good with electronics and the mechanic here seems to have no idea either, so I am hoping things will be relatively straightforward.
Thanks for your help.
 

Andrew123

New member
Thanks Gait.
The engine is a 4M50-3AT7.
The water separater is Ok, I will change the fuel filter again on Monday.
Just to confirm, are you saying there is no way to clean the common rail pressure sensor?
 

gait

Explorer
.... Just to confirm, are you saying there is no way to clean the common rail pressure sensor?

No. Saying that the manual says there is no way to independently test the common rail pressure sensor. Their suggestion is "wiggle the wires". First thought - is the low volts error still there after clearing the errors and taking for a drive? Disconnect and connect in case of dirty connection.

There's a way to test most other sensors (lime measuring resistance etc.).

The bits I provided in earlier posts are from a 4M4 manual. The fault codes seem to be numbered differently to yours. Hopefully someone has a 4M5 manual for you (its a long way from Mongolia to anywhere and I don't know your Mongolian visa situation).

I would still encourage you to look for the diagnostic and memory clear "switches" in the fuse box so you can read and clear the fault codes independently of a computer. One of those "its simple now I've done it once" things.

Back to the fuel filter. When you replace it open up the old one, it may or may not tell you something - all info is useful.

Is there any coloured smoke from exhaust when "crackling" occurs?
 

pugslyyy

Expedition Vehicle Engineer Guy
There was only one page on the Common Rail, which I posted. What else are you looking for?

CAUTION
• Contact each seating surface fully and evenly, tighten the bolt or nut temporarily, and finally tighten it to
the specified torque.
• For servicing the common rail, contact a Bosch Automotive Systems service station.
• If dust enters the common rail, the engine performance will be greatly affected. To prevent it, be sure to
cover up openings left after pipes and other parts are removed. Also, wash eyebolts, gaskets, etc. in light
oil to clear of dirt.
• Before installing, make sure that the seat surfaces of fuel pipes and injection pipes are free of scratches
and irregularities.
 

Andrew123

New member
Thanks for the clarification on the CRPS.
I will check all the things you mentioned.

The exhaust smoke is black when it backfires. The amount of smoke seemed to be getting worse over the past few months. Since the truck was limited to 2000RPM, ther hasn't been any exhaust smoke at all.
I put in a tank of Bio-diesel in Malaysia a few months ago. The smoke seemed to get worse after that. I'm wondering if that had anything to do with the problems now.

We'll be back at it tomorrow, so will let you know how it goes.
 

gait

Explorer
interesting. I wasn't quite sure what answer to expect about the smoke. Black means the diesel is not burning completely. White means its not igniting. Blue is oil burning.

This may suggest we are barking up the wrong tree with the fuel filter (usual solution for low pressure). The black smoke could indicate too much fuel or sufficient fuel / insufficient air. Or cold engine. Also injectors (which I know you've changed).

Simple things first. Silly questions .... What have ambient air temperatures been like? What's the engine temperature like (is thermostat working correctly)? Have you considered draining the tank and replacing fuel (bad batch of fuel) - my recollection from first post is trouble started when driving up one particular hill.

The voltage fault for the common rail pressure sensor may be real, it may occasionally cause fuel pressure to be too high. Wiggle the wires at the sensor and the engine control unit (ECU) which is under the dash, possibly behind the gloveboxes. But be careful there's lots of wires and several large connectors that can be disturbed. Manual knows which connector has the pressure sensor wires.
 

Andrew123

New member
I think the problem is too little fuel. The temperature has varied a lot, from 30deg in the south of China to 0 deg here.
I was having overheating problems in the SE Asian countries, so I took the thermostat out, (though it does seem to work OK) and a bigger radiator was put in. I do think the issue is a fuel one, though new fuel has been put back in. I never drained the tanks though, (I have 2). One thing I am also concerned about is that the 2 tanks were actually taken out and the fuel gauges were adjusted in Laos, (I was having issues with them). I can't see any fuel leaks, but there is a possibility a fuel line has been pinched, though that should've become obvious by now. I did smell and see diesel on the rear mud guard one day and I thought there was a leak. I cleaned it and I never saw it again.

I will have a look at the wires tomorrow.
Thanks for your help.
 

mog

Kodiak Buckaroo
I think the problem is too little fuel. The temperature has varied a lot, from 30deg in the south of China to 0 deg here.
I was having overheating problems in the SE Asian countries, so I took the thermostat out, (though it does seem to work OK) and a bigger radiator was put in. I do think the issue is a fuel one, though new fuel has been put back in. I never drained the tanks though, (I have 2). One thing I am also concerned about is that the 2 tanks were actually taken out and the fuel gauges were adjusted in Laos, (I was having issues with them). I can't see any fuel leaks, but there is a possibility a fuel line has been pinched, though that should've become obvious by now. I did smell and see diesel on the rear mud guard one day and I thought there was a leak. I cleaned it and I never saw it again.
I will have a look at the wires tomorrow.
Thanks for your help.

With black smoke, what about just poor fuel quality not quantity?
Also generally removing the thermostat can hinder cooling. IF the thermostat is working correctly, it acts as a planned upon restrictor to control flow in the cooling system. With it removed, the coolant could be flowing to quickly and not transferring heat as well as planned. Now of course if your thermostat was bad, removing it is a quick fix to get you going, but it should be replaced with a new one. Also without the thermostat, in cold weather (such as you are in now) your engine might not be able to operate in the proper temperature range and with computer controls these days, who knows if that is throw error codes?
BTW I've operated my Fuso (older of course) in 110F (43 C) weather without any increase in operating temps (my ignition switch does stop working in over 100 F weather, but that is an oddball problem)
 

gait

Explorer
Just for info. I (FG649 with 4D3 pre common rail engine) had some overheating problems in Turkey due to a combination of low grade fuel, higher speeds, steeper longer hills and higher air temperatures. Radiator cap replaced helped. Different engine, no misfire.

I'd suggest replace the thermostat. If nothing else the engine running cold can change the symptoms from other problems.

You are now at 1360m above sea level though far from the level where the electronics will complain (about 3,500 - 4,000m). But may be sufficient to effect a fuel system that was marginal but working at lower altitude.

Recollection from a long time ago is there's a mesh filter on the end of the suction pipe in the fuel tank. Unlikely a problem but.... The two pipes, (supply and return) and fuel gauge sender are removed by undoing the six or so screws around them on the tank (assuming standard tanks).

I suggest tighten the hose clips on the fuel supply pipe at the fuel tank. Screw clamps are better than the original spring clamps. A very small (pinhole) air leak can be enough to reduce fuel supply but not enough to collect air in the fuel filter. Though it tended to just slow my engine down until it stops rather than misfire.

With some dual tank instals with changeover there can be a small pressure drop across the junction which requires an extra lift pump to overcome.

At one time I put a temporary pipe direct from fuel tank to fuel filter which allowed me to isolate a fuel line problem. There's a wonderful auto parts place in Ulaan Bataar just where the main road west through the power stations leaves the main road north that has more sizes of fuel line than I've had hot dinners.

Big silly question. Does the engine behave the same way with both fuel tanks ?????????? Did the biodiesel get into both tanks? Were both tanks ever filled at the same fuel station (I avoid that where I can). Flushing one tank and refilling can provide a way of isolating fuel supply as a problem.

Valve clearances.

A bit early and I'm a bit reluctant to suggest a cylinder compression test.
 

Andrew123

New member
The Thermostat has been put back in again and is operating as it should be. All the oils and filters were changed today. We haven't started it up again, though I'm not expecting the misfiring to go away. The CRPS error still comes up even after the other codes are clear. I am very concerned and at the moment the prognosis looks like the whole fuel system needs to be replaced and I'm looking at a $4000 bill. Not easy.
 

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