"Tweaking" a diesel for better fuel economy

[dogstarmessenger]

I am looking to increase the efficiancy of my BJ70 and my HJ60 and was looking for any suggestions or input as to how to get the best MPG
on another note i just ordered some oil and fuel additive from www.h2oil.com it is nanotechnology and supposed to increase power up to 20% and fuel economy up to 25% while reducing emmisions and reducing engine knock
I should get it by the end of the week and will put it to the test
keep ya posted


Brian

 

[Stone]

Make sure your injectors are clean and to spec. You'll probably see the biggest difference by doing this.

Don't know about the additive thing...if it sounds too good to be true it's probably not true.

 

[VTCruiser]

whats the easiest way to "inspect" the injectors? Can they be rebuilt or do they need to be replaced?

 

[cruiser_guy]

A turbo can increase mileage so long as you don't take advantage of the extra power, yeah right! In Northern California with the hills the turbo will give you extra air to mix with the extra fuel you're giving it to get up those hills. The combined effect is better combustion and potentially better economy.
Don't ritchen the fuel delivery to gain extra power since you'll loose economy and increase EGT's.
Injectors tend to wear at the tips. I was told by the diesel shop that the tips should be flat with the needle poking out. If they are concave then they are worn and should be rebuilt.

 

[crushers]

ummm, "don't turn up the fuel"?
i would suggestturnup the fuel to the point where it is starting to burn black then back off a 1/3 of a turn. and add propane injection. you will find you do not need as much throttle which in turn gives you better fuel economy...
cheers
Wayne

 

[beanz2]

Brian, if the injectors haven't been rebuilt or if the motor has high mileage, I'd look at least at having the injectors tested. Remove them and take them to a local Denso dealer. Diamond Diesel in Oakland, (510) 532-8500, tested mine for free but you have to remove them from the vehicle and take them in the shop. They do not do any in-vehicle repairs. They charge about $50 per injector to rebuild and made a heap of difference with my 2H.

Dave

 

[Greg_B]

Injectors tend to wear at the tips. I was told by the diesel shop that the tips should be flat with the needle poking out. If they are concave then they are worn and should be rebuilt.

IDI nozzle wear can be a combination of the flat surface eroding away, and the crack pressure weakening, requiring both the nozzle to be replaced and the crack pressure to be reset. DI nozzles many times (not always) can be cleaned, and the crack pressure reset, as the DI nozzles do not have the large flat surface on the bottom the IDI nozzles do so do not take the same beating (at least with the Toyota IDI vs DI nozzles I have seen.

VT, best way is to take all the nozzles out and take them to a diesel shop nearby that has the facilities to inspect and rebuild them. I have found that some shops will take you in the back and show you each nozzles spray pattern/crack pressure.

gb

 

[HZJ60 Guy]

BIG EXHAUST! TURBO!




And yes of course clean injectors.



TB

 

[70sguy]

VT, best way is to take all the nozzles out and take them to a diesel shop nearby that has the facilities to inspect and rebuild them. I have found that some shops will take you in the back and show you each nozzles spray pattern/crack pressure.

gb

Don't do anything to the injectors on your 1HZ, Gehn. I am pretty sure we had them done by Precision West Injection already. Right GB?

Sheldon

 

[cruiser_guy]

ummm, "don't turn up the fuel"?
i would suggestturnup the fuel to the point where it is starting to burn black then back off a 1/3 of a turn. and add propane injection. you will find you do not need as much throttle which in turn gives you better fuel economy...
cheers
Wayne

Don't turn up the fuel if you don't have the turbo. Even with the turbo I found my EGT's were as high as I felt comfortable (1250 F pulling hard uphill at altitude, readings taken before the turbo, I've been as high as 1350-1400 at 12,000ft pulling hard uphill before I noticed and backed out of the throttle) without adjusting the fuel. Turning up the fuel allows you to deliver additional fuel, and as I understand it, it would be similar to additional accelerator travel, which cannot help economy as a gentle foot is always better economy.
Turning up the fuel will give more acceleration and power but at a loss of economy (which goes against your initial question on improving economy).
Not sure how the propane injection factors into the whole equation, but it would be additional to a turbo. Wayne's experiments indicate that propane injection improves economy but I'll wait for a while until some of the folks who are installing propane on their indirect injection get a few 100 thousand miles on them and see how things perform in the long run as far as engine longevity is concerned.
The fact that I've blown a precombustion chamber on a 3B BEFORE installing a turbo likely makes me a little more cautious than Wayne with regards to fuel delivery and propane injection.

And on the question of muffler, not required. I run 2 1/2" pipe only (no muffler) and others run as big as 3".

Oh, the pre-combustion chamber blew out climbing hills in Northern California/Southern Oregon!!

 

[HZJ60 Guy]

Don't do anything to the injectors on your 1HZ, Gehn. I am pretty sure we had them done by Precision West Injection already. Right GB?

Sheldon

Any idea on the injectors in my HZ Sheldon?

TB

 

[lumpy70]

You guys are forgetting a really easy and cheap one...air filter. Diesel starve for air (hence the need for a turbo). Plentiful and clean air is essential.

Craig.

 

[HZJ60 Guy]

You guys are forgetting a really easy and cheap one...air filter. Diesel starve for air (hence the need for a turbo). Plentiful and clean air is essential.

Craig.

Good point Craig. That's the easiest one.




TB

 

[cruiser_guy]

Wayne,

Hills down here in Guatemala are not nicely graded at 6% or climbable in 4th or 5th. I'd guess I was pulling up a hill more like 10 to 12% in 2nd, heavily loaded and at high altitude (I crossed the highest point of the Interamerican Highway shortly after that at well over 12,000 ft after starting near sea level). I like to keep the RPM's down but not at the expense of high EGT's so I tend to shift down sooner when pulling up hills and running higher RPM's.

I'm also hoping that the alloy head/stainless precups will help reduce cracked precups. I'd venture to guess that more than 75% of the precups out there are cracked.

My blown pre-cup could well have been a problem of an overdelivering fuel pump. I had the truck for 10 years before the pre-combustion chamber blew so I can't imagine it's just driving habits. That was before the turbo and before an EGT gauge. I had the exact same fuel pump on that engine that I now have with the turbo and the fuel delivery has NEVER been adjusted and I can get EGT's up to 1250 F and higher if I'm not paying attention. Down here in Central America one can't spend too much time watching the gauges otherwise someone will be doing something foolish in front of you and you won't have time to react!

I'll agree that the turbo will eat up any fuel savings for a significant time period, probably to the point where the cost return is not feasible. There is as you say though, a significant performance boost.

What is required for propane injection on a 3B/AXT turbo and how many km's are on your truck with IDI, turbo and propane? I'm interested after the system has been proved for 50,000 - 100,000 kms with no adverse side effects.

 

[VTCruiser]

Don't do anything to the injectors on your 1HZ, Gehn. I am pretty sure we had them done by Precision West Injection already. Right GB?

Sheldon

Ok, good to know

I should probably replace the air and fuel filters too......

 

[crushers]

hummm, i can not ever remember owning any vehicle for that long. i get bored way before then. 100,000 in the same vehicle? wow, you must really like your vehicle...
go to http://www.dieselperformanceproducts.com/testimonials.html and do some reading...
i have not read all the testimonials yet so maybe someone has that many km on their trucks but don't know...

 

[70sguy]

Any idea on the injectors in my HZ Sheldon?

TB

If you are looking for stuff to do then have em done.. Might as well do em when you put your Turbo on. Your engine ran clean and smooth when we tested it.. no need to play with it's injectors.


Sheldon

 

[cruiser_guy]

hummm, i can not ever remember owning any vehicle for that long. i get bored way before then. 100,000 in the same vehicle? wow, you must really like your vehicle...
go to http://www.dieselperformanceproducts.com/testimonials.html and do some reading...
i have not read all the testimonials yet so maybe someone has that many km on their trucks but don't know...

Wayne,

I've had my '82 BJ60 since the spring of '89. I got it with less than 100,000kM and it's still going strong at over 400,000kM's. I can fix just about anything on it since I've had it long enough to fix seals in various places, not to mention a complete, ground up, rebuild on the 3B in my kids FJ55 etc. It makes me way more comfortable driving across the continent and into Central America in a vehicle that I know that well.
Besides it's too much of a pain to get it where I want it only to sell it to someone else for less than I've invested.

 

[crushers]

i can see your point and i have customers that have owned their trucks since new and they still love them.
me, i am like a kid in the candy shop. "i want one of these and one of those and one of..."
i am glad there are people around that can keep their vehicles as long as you do, makes up for "kids" like me...
cheers
Wayne