Potential cause of poor mileage for FJ80?

[AZ2ME]

you know, I thought I got bad mileage when it dropped to 14. I normally get 17 on the highway at 65+ and 15 in town. I still get 10 towing a 4500# boat!
Now that it's dropped to 12-14 and throwing a P0420 code, I'm looking at new O2 sensors and cats and thought I'd put in new Borla exhaust while I'm in there for better hp and potentially better mpg. But, now I think I'll just do the cats and O2s and hope to get back to 17!

So glad I'm still consistently in double digits.

 

[Firedog]

Options
Cummins 4BT - Great mileage (20-22 from what I have heard) EXPENSIVE, I think you could do the swap for about $10,000 to $15,000

6.5 TD - Better mileage, probably 15 to 20 mpg. not quite as expensive, but still gonna cost....A LOT

Chevy Vortec (or other Chevy fuel injected V8) about 14 mpg, $5000 to $7000 for a good conversion

Turbo (would have to be custom) should give you mileage in the teens with much more power, would probably still cost $6000- $7000

Keep the old girl tuned up, oil changed, put on skinny tires, maybe convert it to to part time, and drive it like an old lady. Should put you in the mid-teens for mpg.

I would think that a newer Toyota engine would be an incredible pain in the butt, no one is doing the conversions, so everything (wireing) would have to be custom snd would be a HUGE hassle. Don't forget, switches don't really operate anything anymore, they request the computer to do it.

Good luck

 

[Nay]

swapping out the engine is needed I think.

No s***.

Don't put in a 1ZFE, though, that's expensive lipstick for a pig.

 

[fzjconvert]

Maybe the H3 has less low end power than the '91 FJ80. I was thinking that taking a engine and putting it into the FJ80 should yeild a lot better mileage than it currently gets. I'm also wondering what other things are different that could cause the FJ80 to get worse mileage than other similarly weighed vehicles. Are there dyno charts of this vehicle (both engines) from idle all the way to 5K rpm?

This is the one you want to hold out for... 300+ HP and 500ft lbs at 1800 RPM It fits in the same envelope as a small block. Here is the best part up-wards of 30 MPG right out of the box. Tell me that wouldn't be the sh** in an 80....

GM News - 4.5L V-8 Duramax Diesel - July 2007 - The Diesel Page

 

[Brian Macgyver]

There is another option; There is an amazing mileage solution well known as the "Corolla". It is available in a wide range of reliable versions ranging from the mid-"80's models to current, depending on your access to rust-free older cars. In AZ I have even seen clean models back to 1978 in good condition. Fuel mileage ranges up to 40 MPG!
The LC80 is not an econo-box. It was never intended to be one. It is a 6,000 pound truck with an under-size engine that produces a lot of brute torque. It is not built to go fast on the highway, nor was it designed to sip fuel. It was made to climb large rocks and small trees. The 80, or any other LC, is a tractor with AC. It has all of the aerodynamics of a pine coffin, and fuel mileage to match.
You could buy any of a number of lighter trucks and get better mileage. The Chevy 3/4-ton 4wd weighs a lot less and gets better mileage from a bigger engine, but when the road gets rough, it craps out! The same is true of Ford and Jeep. Dodge frames break in the middle under hard use, as do Jeeps. The LC has no such issues. It just keeps going!
If mileage is such an issue for you, buy an old econo-box for cash and beat it on the weekdays. Save your LC for weekends.

 

[sundaypunch]

A stock FZJ80 in good tune will get 17mpg on the highway. That is very close to the H3.

 

[Mike S]

This is the one you want to hold out for... 300+ HP and 500ft lbs at 1800 RPM It fits in the same envelope as a small block. Here is the best part up-wards of 30 MPG right out of the box. Tell me that wouldn't be the sh** in an 80....

GM News - 4.5L V-8 Duramax Diesel - July 2007 - The Diesel Page

I am planning on buying a GMC or Chev 1/2 ton with this drive train.

I talked to Jonathan Ward at TLC recently on the subject of transplanting one of these engines into my '96 80. Since there is no aftermarket swap support, and no crate engines offered, it would be a very custom job. Jonathan figured you'd probably have to swap in the whole drive train - engine and tranny, possibly the TC as well. Then there are the electrics and computer controls. You then have a Chevy with a Toyota frame and body. Is this what you want? I am not so sure.

The engine is claimed to offer mileage in the mid 20s, but that is from the manufacturer. I would be happy with 20 MPG.

Mike

 

[fzjconvert]

I am planning on buying a GMC or Chev 1/2 ton with this drive train.

I talked to Jonathan Ward at TLC recently on the subject of transplanting one of these engines into my '96 80. Since there is no aftermarket swap support, and no crate engines offered, it would be a very custom job. Jonathan figured you'd probably have to swap in the whole drive train - engine and tranny, possibly the TC as well. Then there are the electrics and computer controls. You then have a Chevy with a Toyota frame and body. Is this what you want? I am not so sure.

The engine is claimed to offer mileage in the mid 20s, but that is from the manufacturer. I would be happy with 20 MPG.

Mike

Not to disagree with the all knowing Mr. Ward At TLC. But hell any company that sells vehicles for up wards of $145.000 for a glorified fj40. Well? Of course he is going to say you have to replace this and that. He is in business to make money.. Nothing wrong with that! Also, this is not to say that TLC is not a good company and that they don't stand behind their work. They definitely do! What I am saying is, that years ago if you told people that you were going swap an 80 motor with say a 6bt, 4bt, 6.2, 6.5 just to name the more common swaps I have seen. They would scoff and say you are nuts. Now it is fairly routine. The same will be true for this motor. Our brothers down under will take the Holden counterpart and figure it out for sure. The other thing you should keep in mind is that GM redesigned this diesel. In doing so they made no mention of having to redesign a whole new tranny to accommodate it. In fact they have made the point time and time again it will fit in the same envelope as a standard small block. That tells me it is meant to work in many different configurations.

Anyway time will tell and the market will dictate the outcome....
Dave

 

[josharre2000]

Maybe the H3 has less low end power than the '91 FJ80. I was thinking that taking a engine and putting it into the FJ80 should yeild a lot better mileage than it currently gets. I'm also wondering what other things are different that could cause the FJ80 to get worse mileage than other similarly weighed vehicles. Are there dyno charts of this vehicle (both engines) from idle all the way to 5K rpm?

the 3FEs and 1FZEs were not designed to be fuel efficient. They were designed to run 200k before rebuild. That H3 (along with most GM cars) will be in a 4ft x 4ft cube in 11 years while my 6 year old (current day) will dirving the '97LX as his 1st rig.

 

[Hilux]

If you'll consider the technologies and energy $'s available at the time, theres you answer. Comparing two, one made at the turn of the century (so to speak) is really not going to get you anywhere.

A mechanic buddy of mine had a Tundra at his shop and compared to my 94 4Runner I can pull the Tundras engine in 30 minutes. Why? All the emissions are computer controlled now and from what I saw IIRC, the Tundra had only ONE vacuum line and sparse, almost no emissions controls. Aside from the motor mounts and bell housing there was very little joining the engine to the engine bay.


Its in the management

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