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

Peter L

New Member
I am in denmark
Aug 16, 2016
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Denmark
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

180201: Issue resolved as described in this thread. Root cause was false air coming from defective fuel filter feed/pump (the one you use to get diesel to fuel filter after e.g. after replacing fuel filter)
 
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grantw

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Hi Peter,
First question others that know more will ask is if it's running on LPG or not?

Cheers
 
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StarCruiser

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Hi Peter and welcome to this most friendly forum.
I'll confess I'm no expert on these things but it sounds to me like insufficient compression.

Some questions,

Does it start easily or take a bit to get it going?
I'm not familiar with Bell Ad or Nova Powerkleen, what are they and how are they applied?
Does it use any oil?
Does it use any coolant?
Have you checked/drained any water from your fuel filter?
Could you possibly have a tank of bad fuel?
Have there been any modifications made to the engine such as the addition of an after market turbo for instance?

Regards

Richard
 
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Peter L

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I am in denmark
Aug 16, 2016
18
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Denmark
Thanks for reply Ben.
I have checked fuel line together with mechanic, but we did not find any issue in fuel line or fuel tank. However I don't know if you can measure that fuel pressure is sufficient at high load. Hence we still suspect that somehow engine is not getting sufficient diesel at high load. And this issue has developed within last 6 months.
The diesel always come from tank station.
br Peter
 

CruiserMania

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Jan 17, 2018
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If IP and injectors were never refurbished, repaired, 300.000 kms is enough to have some tear that can produce fuel starvation at high load, especialy the lift pump inside the IP.
If you do not want to remove IP and injectors, you might try to insert an electric fuel lift pump inline with fuel lines to see if you notice any improvement.
 
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Peter L

New Member
I am in denmark
Aug 16, 2016
18
3
3
Denmark
Hi Richard

Thanks a lot for your reply.

Pls. let me answer point by point:


  1. Does it start easily or take a bit to get it going?
Peter: yes it starts right away

  1. I'm not familiar with Bell Add or Nova Powerkleen, what are they and how are they applied?
Peter: These diesel adds are used to clean fuel line and nozzles, ref. e.g. http://www.novatio.be/en/products/novafuel-powerkleen-rfu. They are applied to the diesel in tank.

  1. Does it use any oil?
Peter: no

  1. Does it use any coolant?
Peter: no

  1. Have you checked/drained any water from your fuel filter?
Peter: fuel filter replaced, same issue though. Btw there is no filter absorbing water from diesel on this model (water separator)

  1. Could you possibly have a tank of bad fuel?
Peter: no, tank has been replaced and fuel is the best quality I can buy at tank station.

  1. Have there been any modifications made to the engine such as the addition of an after market turbo for instance?
Peter: no, this is the original 1HZ engine without turbo. Btw. Fuel is sucked from tank, no electric pump to apply fuel pressure. I am considering to install electric fuel pump, however as this issue only developed within last 6 months I really wonder if this could be the root cause.



Thanks again for your suggestions

Br

Peter
 

grantw

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Also just to check - when you cleaned the fuel tank out the filter/gauze on the fuel pick up was also clear?
 

Peter L

New Member
I am in denmark
Aug 16, 2016
18
3
3
Denmark
Thanks for your valuable suggestion. I was actually thinking about the electric fuel pump already, so I will try this as 1. step. But still I wonder why this only developed within last 6 months -as you say it may be time to renovate pump and nozzles. So before doing that I will try adding electric fuel pump.
 

Peter L

New Member
I am in denmark
Aug 16, 2016
18
3
3
Denmark
If IP and injectors were never refurbished, repaired, 300.000 kms is enough to have some tear that can produce fuel starvation at high load, especialy the lift pump inside the IP.
If you do not want to remove IP and injectors, you might try to insert an electric fuel lift pump inline with fuel lines to see if you notice any improvement.
Thanks for your valuable suggestion. I was actually thinking about the electric fuel pump already, so I will try this as 1. step. But still I wonder why this only developed within last 6 months -as you say it may be time to renovate pump and nozzles. So before doing that I will try adding electric fuel pump.

Also just to check - when you cleaned the fuel tank out the filter/gauze on the fuel pick up was also clear?
yes
 
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Peter L

New Member
I am in denmark
Aug 16, 2016
18
3
3
Denmark
If IP and injectors were never refurbished, repaired, 300.000 kms is enough to have some tear that can produce fuel starvation at high load, especialy the lift pump inside the IP.
If you do not want to remove IP and injectors, you might try to insert an electric fuel lift pump inline with fuel lines to see if you notice any improvement.
Thanks for your valuable suggestion. I was actually thinking about the electric fuel pump already, so I will try this as 1. step. But still I wonder why this only developed within last 6 months -as you say it may be time to renovate pump and nozzles. So before doing that I will try adding electric fuel pump.
 

StarCruiser

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Oct 7, 2014
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Given all your replies, as Grant says, unburnt fuel would exit as white smoke, for fuel to be unburned, low compression could be the cause. I suggest doing a compression test would be useful if only to eliminate compression from the equation. The FSM advice on the distributor type of pump is that with any problems it won't be the pump but could be delivery valves. I don't think your problem is delivery valves, though injectors could be in need of a refurb, but if it was injectors I would expect to see the issue at other times than what you say but that is just my thoughts for the moment.
 
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Peter L

New Member
I am in denmark
Aug 16, 2016
18
3
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Denmark
Given all your replies, as Grant says I burnt fuel would exit as white smoke, for fuel to be unburned, low compression could be the cause. I suggest doing a compression test would be useful if only to eliminate compression from the equation. The FSM advice on the distributor type of pump is that with any problems it won't be the pump but could be delivery valves. I don't think your problem is delivery valves, though injectors could be in need of a refurb, but if it was injectors I would expect to see the issue at other times than what you say but that Ines just my thoughts for the moment.
Thanks Richard, I will do compression test also before taking out pump and injectors for refurb.
 

frank rabbets

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Sounds like a fuel injection timing problem. i.e it's retarded and the fuel is being injected too late and is vaporizing rather than combusting. There is most likely an automatic advance system in the pump. This advances the timing in accordance with RPM and if it fails that is why you have the problem at high RPM. If you have white smoke also at low RPM the static pump timing needs checking. I think if you had fuel starvation you would only get loss of power and no smoke. The white smoke is most likely the unburnt fuel.

What you could do is get the engine up to temperature and then get high RPM on it and suddenly lift off the throttle when the smoke should cease. If the smoke gets worse during this process it points to engine oil white smoke but you say it is not using oil. I would therefore check the static timing first and then the dynamic timing. The latter would mean removing the pump and sending away to a pump specialist.
 

Peter L

New Member
I am in denmark
Aug 16, 2016
18
3
3
Denmark
Sounds like a fuel injection timing problem. i.e it's retarded and the fuel is being injected too late and is vaporizing rather than combusting. There is most likely an automatic advance system in the pump. This advances the timing in accordance with RPM and if it fails that is why you have the problem at high RPM. If you have white smoke also at low RPM the static pump timing needs checking. I think if you had fuel starvation you would only get loss of power and no smoke. The white smoke is most likely the unburnt fuel.

What you could do is get the engine up to temperature and then get high RPM on it and suddenly lift off the throttle when the smoke should cease. If the smoke gets worse during this process it points to engine oil white smoke but you say it is not using oil. I would therefore check the static timing first and then the dynamic timing. The latter would mean removing the pump and sending away to a pump specialist.
 

Peter L

New Member
I am in denmark
Aug 16, 2016
18
3
3
Denmark
Thanks Frank, given that I only see this issue at high RPM, I just want to see what checks I should do before possibly renovating pump and nozzles. So far I will as suggested in this thread
1. check compression (although I would expect issue at low RPM if there was a compression issue)
2. install electric fuel pump (although this 1HZ engine originally is using suction only)
br
Peter
 

StarCruiser

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+1 on Frank as he clearly knows what's going on here rather than my generic troubleshooting approach.
I will however add that I don't think the electric pump will cure it, as Frank says, you would lose power with fuel starvation, but not get the smoke.

Interesting one.
 
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