JDM Toyota Dyna 3L Smoke issue - altitude?

[hobojordo]

Hello!
I have this 97 Dyna 3L with only 8k km on the motor.
I recently got it and its a great little truck in many ways - but it emits quite a bit of black smoke - especially when climbing hills. Ends up coating the bed and anything in the bed with a greasy black film.
The truck is new to me so it could be anything - but as the truck was brought from Japan and now live between 4000-7000' in elevation in Idaho/Montana I wonder if its not caused by an elevation issue? Might be a good place for me to start.
Is there an elevation adjustment to be made, and if so, what screw on the injector pump is it?
I was at 7000' today and the symptom were worse- usually it runs smokey but fine - there it was noticeably hiccupping.

Any thoughts?

Thanks!
Jordan

 

[Eurasiaoverland]

Welcome to MUD, nice truck you have there.

Forgive me for asking, but are you used to driving old diesels? The reason I ask is that these vehicles are, by modern standards, very underpowered, and without a turbocharger this problem becomes worse at altitude. Point it at a hill and this becomes worse still.

Black smoke is caused by there being too much fuel injected into the engine for the amount of oxygen it is receiving. I've driven a Hilux truck with the smaller 2L engine to well in excess of 4000 metres and at that altitude it is easy to make the engine smoke. You need to be very careful on the accelerator pedal and in a low gear to hope to avoid it.

I don't necessarily think there is anything wrong with the engine if your driving technique is to floor the pedal in a high gear under these conditions. But a blocked air filter or incorrect engine timing could be a contributor.

Hiccuping sugegsts there is a fuel delivery problem. It's easy to get air into the fuel system if hoses/seals etc have deteriorated. But this usually causes blueish-white smoke from unburned fuel - black smoke is incomplete combustion. So I don't necessarily think the two are connected.

There is something called a high altitude compensator, a part of the fuel injection pump, which was fitted in some markets. But all this does is reduce the amount of fuel injected as air pressure decreases. You can do much the same by backing off the accelerator a bit.

EO

 

[GTSSportCoupe]

Please also note, that Toyota's Indirect Injection Diesels (what you have) of this era LIKE to be revved. Do NOT lug the engine. When under high load, you need to operate between peak torque and peak hp. They're made to rev. So 2400-4000rpm is fine. Under greatest load, sitting at 3500rpm for hours for example is not a problem.

As mentioned above, it's worth checking to see if your injection pump has an altitude compensator; if it does, maybe something is out of adjustment.

Black smoke will mean high EGT temperatures; that is really not good for a diesel. Ideally you don't want that.

 

[hobojordo]

Welcome to MUD, nice truck you have there.

Forgive me for asking, but are you used to driving old diesels? The reason I ask is that these vehicles are, by modern standards, very underpowered, and without a turbocharger this problem becomes worse at altitude. Point it at a hill and this becomes worse still.

Black smoke is caused by there being too much fuel injected into the engine for the amount of oxygen it is receiving. I've driven a Hilux truck with the smaller 2L engine to well in excess of 4000 metres and at that altitude it is easy to make the engine smoke. You need to be very careful on the accelerator pedal and in a low gear to hope to avoid it.

I don't necessarily think there is anything wrong with the engine if your driving technique is to floor the pedal in a high gear under these conditions. But a blocked air filter or incorrect engine timing could be a contributor.

Hiccuping sugegsts there is a fuel delivery problem. It's easy to get air into the fuel system if hoses/seals etc have deteriorated. But this usually causes blueish-white smoke from unburned fuel - black smoke is incomplete combustion. So I don't necessarily think the two are connected.

There is something called a high altitude compensator, a part of the fuel injection pump, which was fitted in some markets. But all this does is reduce the amount of fuel injected as air pressure decreases. You can do much the same by backing off the accelerator a bit.

EO

Ahh thanks - nope - learning curve on the old Diesels though I don’t mind the fact that it slows, it does seem a bit excessive on the smoke. I’ll try to lay off a bit on the hills and downshift.

Please also note, that Toyota's Indirect Injection Diesels (what you have) of this era LIKE to be revved. Do NOT lug the engine. When under high load, you need to operate between peak torque and peak hp. They're made to rev. So 2400-4000rpm is fine. Under greatest load, sitting at 3500rpm for hours for example is not a problem.

As mentioned above, it's worth checking to see if your injection pump has an altitude compensator; if it does, maybe something is out of adjustment.

Black smoke will mean high EGT temperatures; that is really not good for a diesel. Ideally you don't want that.

It’s good to know their ideal RPMs thank you.

Do you think this is the altitude screw?

 

[Eurasiaoverland]

There is no such thing as an altitude screw - that is the max fuel screw. Your pump does not have a high altitude compensator. I would strongly recommend that you not adjust any injection pump settings until you fully understand the pump, and therefore understand that it won't solve your problem.

 

[GTSSportCoupe]

There is no such thing as an altitude screw - that is the max fuel screw. Your pump does not have a high altitude compensator. I would strongly recommend that you not adjust any injection pump settings until you fully understand the pump, and therefore understand that it won't solve your problem.

I absolutely agree with this!

Leave the fuel screw alone. Most people end up regretting it when they do.

You could look into installing an altitude compensator. Or drive it easy as suggested above (install pyrometer and drive by that ideally). Or install a low boost turbo with no increase in fuel. (Diesels are cooler running lean).

 

[hobojordo]

I absolutely agree with this!

Leave the fuel screw alone. Most people end up regretting it when they do.

You could look into installing an altitude compensator. Or drive it easy as suggested above (install pyrometer and drive by that ideally). Or install a low boost turbo with no increase in fuel. (Diesels are cooler running lean).

OK sounds good .. appreciate the advice.

I don’t mind it as Is but seeing that the future of this vehicle will be almost exclusively high altitude your suggestions of a low boost turbo or an altitude compensator would be worth looking in to … any suggestions for models that would work with my 3L truck?

I ordered a EGT

 

[GTSSportCoupe]

OK sounds good .. appreciate the advice.

I don’t mind it as Is but seeing that the future of this vehicle will be almost exclusively high altitude your suggestions of a low boost turbo or an altitude compensator would be worth looking in to … any suggestions for models that would work with my 3L truck?

I ordered a EGT

You could look to Australia for a 3l turbo kit. Many were made for their hiluxes. Maybe not as many anymore as the vehicles are older now. A complete kit is expensive. If you have fab skills you could make your own. Pyrometer and altitude comp are way more affordable. But altitude comp install is finicky and you'll have do your research before buying anything and digging in.

Pyro and right foot calibration might do the trick for now!

 

[hobojordo]

You could look to Australia for a 3l turbo kit. Many were made for their hiluxes. Maybe not as many anymore as the vehicles are older now. A complete kit is expensive. If you have fab skills you could make your own. Pyrometer and altitude comp are way more affordable. But altitude comp install is finicky and you'll have do your research before buying anything and digging in.

Pyro and right foot calibration might do the trick for now!

Ok thanks! I’ll see how that foot modulator goes for now - what’s the temp range I should keep her at?

Appreciate the feedback I’ll stop harassing you with questions for now

 

[GTSSportCoupe]

Mine is turbo and I never go over 1000f. Non turbo you can push harder. 1200f tops I'd suggest personally (sustained for any period of time).

 

[AirheadNut]

Welcome! Cool truck, looks like we're from the same neck of the woods (Whitefish native here). Black smoke from a naturally aspirated IDI diesel is fairly normal when pulling hills at altitude. I would recommend running a bottle of LiquiMoly Diesel Purge through the fuel system, especially since it has spent most of its life sitting idle. Disconnect the fuel supply and return lines from the injection pump and run them both into a bottle of diesel purge and run the engine on it straight until it is gone.

 

[duncanrm]

I would recommend running a bottle of LiquiMoly Diesel Purge through the fuel system, especially since it has spent most of its life sitting idle. Disconnect the fuel supply and return lines from the injection pump and run them both into a bottle of diesel purge and run the engine on it straight until it is gone.

Liqui Moly Diesel Purge PLUS is good stuff.. I think its only the product with "Plus" on the end of the name that can be run undiluted into the pump.. I prefill my new fuel filters with it.

 

[AirheadNut]

Liqui Moly Diesel Purge PLUS is good stuff.. I think its only the product with "Plus" on the end of the name that can be run undiluted into the pump.. I prefill my new fuel filters with it.

I haven't heard of the Diesel Purge Plus, I've always used this stuff: Diesel Purge - https://www.liqui-moly.com/en/us/diesel-purge-p003261.html#2005 It is the only diesel injection cleaner they recommend priming the fuel filter with or running the engine on directly. Might be the same stuff, just a difference in marketing terms between the US and Australia.

 

[duncanrm]

I haven't heard of the Diesel Purge Plus, I've always used this stuff: Diesel Purge - https://www.liqui-moly.com/en/us/diesel-purge-p003261.html#2005 It is the only diesel injection cleaner they recommend priming the fuel filter with or running the engine on directly. Might be the same stuff, just a difference in marketing terms between the US and Australia.

Interesting.. thanks. its clearly designed for exactly what you suggested!

 

[Dougal]

Additives won't do anything. There is less oxygen at higher altitude so you can't burn fuel without smoke.

Your choices are:
1. Drive more gently.
2. Adjust the pump to reduce fuel.
3. Fit a turbo.

 

[bj70bc]

there is clearly only one path forward

 

[mudgudgeon]

low boost turbo

Lots of dead indirect injected diesels due to low boost turbos over the years.

The strategy was commonly bolt on a small turbo, run 5-7 psi boost, crank up the fuel.
Yeah you get more power, but you also get higher EGTs.

Run more boost, 14-15psi-ish, you can actually make full use of the fuel that's being delivered because of the increased oxygen in boosted intake air, and you get a more efficient, more complete fuel burn and lower EGTs.

The gotcha with a turbo is, it let's you burn more fuel, but an indirect injected diesel is already running a dirty inefficient AFR.
Adding more fuel without improving the afr means more heat. Indirect injection diesels hold more heat in the head due to precombustion chambers.

More boost can be safer.

 

[GTSSportCoupe]

Lots of dead indirect injected diesels due to low boost turbos over the years.

The strategy was commonly bolt on a small turbo, run 5-7 psi boost, crank up the fuel.
Yeah you get more power, but you also get higher EGTs.

Run more boost, 14-15psi-ish, you can actually make full use of the fuel that's being delivered because of the increased oxygen in boosted intake air, and you get a more efficient, more complete fuel burn and lower EGTs.

The gotcha with a turbo is, it let's you burn more fuel, but an indirect injected diesel is already running a dirty inefficient AFR.
Adding more fuel without improving the afr means more heat. Indirect injection diesels hold more heat in the head due to precombustion chambers.

More boost can be safer.

I was suggesting low boost with no fuel increase, so would improve his high altitude situation with lower EGT's. Of course higher boost and some added fuel is nice. But coolant temps will get higher, and he'll need to spend more for intercooler.... It never ends.

 

[bj70bc]

i find these idi engine need a bit of help breathing properly
it is a rabbit hole though

 

[mudgudgeon]

It never ends.

That's it in a nutshell.

Settle for what it is, or go down a rabbit hole of 'upgrades and improvements' on what is always gonna be underpowered and slow.