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HZJ80 1HZ engine gives white smoke and stalls at high load - no issue at normal load

Also Peter, if your truck has the Automatic cold start Device (ACSD for short), a cartridge on the side of the IP with two pipes going to the engine block, these can sometimes break their part that is inside the pump. It can be removed for inspection or removed altogether (search ACSD on here). It advances the timing and brings up the idle for cold starting. If this has broken, the broken part can cause damage inside the pump. As this acts on the advance mechanism inside the pump it's possible it could have jammed it or otherwise affected it. Could be worth removing and inspecting it. It's only three bolts and a lost pint of diesel.
 
Yes that might be worth looking at Richard especially with sudden appearance. There is a spherical nipple on the ACSD visible on the rear rotating plate when it is removed. If it's gone it could well be inside the pump.

Actually an improved fuel flow might solve any faulty advance. Some pumps require good internal pressure to activate the system and air or vacuum bubbles may be in there at high RPM. Also there is a filter in the HP pump itself but I've not seen one and don't know offhand how to get it out. Obviously an additional pump would not solve the original car problem starving the pump of fuel.
 
I've just checked the VE pump manual and the advance relies on the increased fuel pressure during high RPM to advance the timing so a blockage or poor fuel flow may, I assume, be the problem. Worth looking for that little inlet filter? I would take the fuel inlet pipe off and see what else can be removed without upsetting the pump to find the filter. Now I'm certain I've read or talked about this filter but cannot at present find reference for or against it's existence.
 
Thanks Frank and Richard.
As mentioned I want to check as much as possible before removing pump and nozzles. Personally I don't think that electric pump will help to find the root cause. So next steps before removing any part of fuel line I think could be:
1. cleaning nozzles and pump with direct injection of bell add or powerkleen
2. compression test after completing 1.
br
Peter
 
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I've just checked the VE pump manual and the advance relies on the increased fuel pressure during high RPM to advance the timing so a blockage or poor fuel flow may, I assume, be the problem. Worth looking for that little inlet filter? I would take the fuel inlet pipe off and see what else can be removed without upsetting the pump to find the filter. Now I'm certain I've read or talked about this filter but cannot at present find reference for or against it's existence.
Hi Frank Seems like a good idea, where do I find this inlet filter?
 
How to check that?

Not sure about your truck but unless you have a snorkel the air is sucked into the air box from inside the wing somewhere . Restrict air and it will cause an inefficient burn resulting in unburnt diesel being fired out the exhaust .

It's a long shot but i vaguely remember reading about someone in OZ who discovered a snake in the intake pickup .
 
Doesn't air starvation give black smoke though Shayne?
 
It's a long shot anyway Rich but it costs nothing to rule it out . I don't read books or follow a diagnostic process so i'm not very good at explanations but i can picture a lack of air presenting as a timing issue higher up in the rev range , no fire in one cylinder perhaps randomly , air ignites the fuel so no air no bang . Completely unburnt diesel will exhaust as white smoke i believe .
 
Hi
Just to comment on air intake: My HZJ80 is original and unmodified. So for air intake under right wing I don't see any blocking. Also K&N air filter has been completely cleaned. Hence I think we can rule air intake out.
 
Hi

Since last 6 months I have been fighting below issue:


When accelerating HZJ80 with 1HZ engine e.g. to 80 km/h in 3. shift engine is giving heavy white/gray smoke and starts stalling as if engine is not getting sufficient diesel.

However if you don’t press/stress engine there is no issue, i.e. you only see this at high load.

Tank and fuel filter have been replaced, cleaned with bell ad and Nova Powerkleen RFU also, no change though.

Injection nozzles and pump have not yet been touched or renovated at this engine.

Engine has been running appr. 300.000 km now without issues - except this one, which has come within last 6 months.

Any suggestions are welcome.


Br

Peter

Hi all

Issue was false air, caused by faulty membrane in the manual pump sitting on top of fuel filter (the one to which fuel filter is attached).
This was found by temporarily attaching a piece of transparent hose to each side of the fuel filter.
In my case you could then see air bubbles on the output side after the fuel filter (towards pump), but not on input side (towards fuel tank)
So no issue with fuel pump or injectors, and no additional electric pump required.


br Peter
 
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well done Peter,
glad you sorted it out!
 
Well done finding it Peter. always good to find the smoking gun.
 
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