LJ78 2LTE typical city mileage? (1 Viewer)

[GTSSportCoupe]

Hey guys. I must admit I'm pretty bummed about the fuel mileage that my LJ78 is returning. It's a real disappointment to have a gutless engine AND crappy fuel mileage. I like the idea of the better efficiency of diesel engines....but I think I'm getting typical 6 cylinder gasser economy.

Reading through the forums, it seems most LJ78 owners are getting in the low to mid 20's imp mpg in the city, and up to 30 on the highway.

Average driving I've been getting around 17 imp mpg (14 us mpg or 16.5 l/100km) city driving. This seems like FZJ80 territory.

Driving like an angel on my last tank, I saw 18.7 imp mpg (15.6 us mpg or 15.1 l/100km) city driving.

My drives are primarily short ~10km and in medium/heavy city traffic. Is this the best fuel economy I can expect on a stock engine?

The engine is in pretty decent shape with a new air filter, rebuilt turbo and recently cleaned injectors. Compression seems good. It doesnt smoke at all unless I get on it (then it leaves a little trail of black).

The thermostat is a 82C unit and the factory temp gauge sits around 1/3. Would this make the engine run richer?

I am running aggressive 235/85/16 tires, and have compensated for the bigger diameter in my calculations. I've got the tires at 42psi.

Brakes don't seem to be dragging.

I will be installing larger exhaust and a manual boost controller in the next couple months. Will I see better fuel economy with these mods?

Also, the engine is due for a new timing belt which I'll be doing soon. I think I heard somewhere that old timing belts can stretch and put out the fuel pump timing. Could this effect fuel mileage?

Thanks for any ideas. I know there are still a few LJ78 owners lurking on these forums.

 

[Gun Runner 5]

1st premise: I drove at speeds that my grandmother would have considered slow.
2nd premise: I often ran my A/C.
I don't recall the exact numbers but I suspect the city mileage averaged around 17-18 mpg and the combination city/highway was somewhere in the 22-23mpg range. Considering the 2L-TE produces like 9 horsepower you would have expected 50 mpg.

 

[GTSSportCoupe]

1st premise: I drove at speeds that my grandmother would have considered slow.
2nd premise: I often ran my A/C.
I don't recall the exact numbers but I suspect the city mileage averaged around 17-18 mpg and the combination city/highway was somewhere in the 22-23mpg range. Considering the 2L-TE produces like 9 horsepower you would have expected 50 mpg.

Thanks for the reply! I'm assuming your numbers are in US MPG? I don't have working A/C, and it's cold here right now anyhow, so that doesn't play into the equation for me.

Heh, my last tank I made a lot of people un-happy with how slow I was accelerating from stop in town. They'd get around me as soon as they had a chance. I thought driving like that would gain me more than 1.5mpg though!

 

[Gun Runner 5]

Yes .... U.S. mpg. Fortunately for me to bulk of the ugly stares were directed at my kids who were setting in the passenger seat ( most of the angry people did not realize it was a RHD vehicle. You can of course force the 2L-TE to go faster if you don't mind watching the pyrometer go to a ga-zillion degrees.

 

[Gun Runner 5]

" I know there are still a few LJ78 owners lurking on these forums. " ..... most are in the Land Cruiser version of the "witness protection" program or in therapy and embarrassed to admit it on a public forum.

 

[Radd Cruisers]

Timing belts do not stretch appreciably. I would have to say that you really should not be going over the replacement interval - and do the water pump and accessory belts, rad hoses, rad cap, thermostat etc... at the same time. If the timing has skipped a tooth, then yes you might get really bad fuel economy and low power.

We keep loads of these belt kits in stock if you are looking for the parts.

2LTEs do not typically get very good fuel economy for what they are, but you are getting really bad fuel economy - I would have to say that you have a problem with boost compensation or something else (which is controlled by a MAP sensor).

If you really are getting fuel economy that is that bad, then you really need to look at why that's happening - it's a lot more that's going on (wrong) than just putting in a larger exhaust or a fresh air filter.


~John

 

[Redd]

i had one, i dont know the figures, but short runs made no sense in it. your hauling a lot of metal around. now ive got a bigger heavier engine with heavier axles, a gearbox that weighs more than jupiter and the governments raping us for diesel.

lol.

 

[GTSSportCoupe]

Yes .... U.S. mpg. Fortunately for me to bulk of the ugly stares were directed at my kids who were setting in the passenger seat ( most of the angry people did not realize it was a RHD vehicle. You can of course force the 2L-TE to go faster if you don't mind watching the pyrometer go to a ga-zillion degrees.

Haha! I never thought about that! I guess they'd see an empty seat in my case. Although with the larger tires and lift, the truck is high enough it's hard for people in cars to see in anyhow. I've gotta get my pyro in asap so I know where I'm at. Funny thing is though, the vehicle has been in Canada for 6+ years, seeing ignorant owner abuse with no pyro. Somehow (it's beyond me), the thing has not suffered any head problems.

" I know there are still a few LJ78 owners lurking on these forums. " ..... most are in the Land Cruiser version of the "witness protection" program or in therapy and embarrassed to admit it on a public forum.

Haha! As much as these vehicles (engines I should say) have a bad rap, I really love mine. For my needs it is the perfect cruiser. I wish it had a 1HZ, but otherwise it is an awesome machine. I like the 70 series body and interior, and I like the 80 series style coil suspension and comfy interior/options. It may not be as tough as the other 70 series wagons, but I also paid about 1/6th what an HZJ77 or similar would have cost me. I feel its 75% the truck that an HZJ77 is. The only other option out there in a similar price range to what I paid is a 4Runner. I think even an LJ78 is twice the truck that a 4Runner is.

Timing belts do not stretch appreciably. I would have to say that you really should not be going over the replacement interval - and do the water pump and accessory belts, rad hoses, rad cap, thermostat etc... at the same time. If the timing has skipped a tooth, then yes you might get really bad fuel economy and low power.

We keep loads of these belt kits in stock if you are looking for the parts.

2LTEs do not typically get very good fuel economy for what they are, but you are getting really bad fuel economy - I would have to say that you have a problem with boost compensation or something else (which is controlled by a MAP sensor).

If you really are getting fuel economy that is that bad, then you really need to look at why that's happening - it's a lot more that's going on (wrong) than just putting in a larger exhaust or a fresh air filter.


~John

Hi John, thanks for your post, I really appreciate your input.

I will be doing the full timing belt and cooling system service very soon now (wife asked me to do some house renos before I work more on my cruiser). I'm glad to hear that timing belts don't cause injector pump issues unless they've skipped though. I would say mine has definitely not skipped. It's got very healthy power output for the engine that it is.

I'm glad you've got belt kits in stock. I'll have to call you guys about that. I've also been waiting to hear back from Rob on your front axle seal kits. I think he forgot about my request for a quote. I'm very happy with the OME suspension I bought from you guys though.

Thanks for confirming that my fuel economy sucks. At least I know now I'm not chasing down an imaginary problem. I'll do the full engine service, block off the EGR, clean out the intake manifold, etc. and see where my mileage is at after that. If it still sucks, I'll start troubleshooting the more subtle things like engine temp sensor, MAP sensor, TPS etc. Hopefully my injection pump isn't hosed. I've been running a diesel additive (power service), but I don't think the previous owners did.

i had one, i dont know the figures, but short runs made no sense in it. your hauling a lot of metal around. now ive got a bigger heavier engine with heavier axles, a gearbox that weighs more than jupiter and the governments raping us for diesel.
lol.

Hey Redd, yeah, I know short runs don't make that much sense, but this truck has to double as my daily driver as well as a back country machine. I weighed my truck and she is 4500lbs with nothing in it but a full tank of diesel. Light for a landcruiser maybe, but still a lot of mass to haul around for sure.

Thanks everyone. I'll let you know how I make out with chasing down my fuel economy problems.

Nick

 

[Gun Runner 5]

To set the record straight I never had any issues with my LJ78 however after all of the "gloom and doom" reports about the engine I could never relax and just enjoy the Cruiser. I spent more time looking at engine gauges than I did the road which took all of the enjoyment out of ownership. If I had it to do again I would have kept the LJ78 and just dealt with the engine issues as they arose.

 

[Redd]

skinnier tyres with a less aggressive pattern might be a good move.
for instance, if you stick the clutch in and freewheel, how long does it take you to come to a stop?
i had a permanent 4wd niva that wouldnt coast at all. the rolling resistance will affect your milage.
currently i have 7.50 R16 michelin xzl's on and i get excellent mileage for a mud tyre, but theyre less good at other stuff like rain.

on longer journeys it pays to keep the weight down and the revs high.

 

[GTSSportCoupe]

To set the record straight I never had any issues with my LJ78 however after all of the "gloom and doom" reports about the engine I could never relax and just enjoy the Cruiser. I spent more time looking at engine gauges than I did the road which took all of the enjoyment out of ownership. If I had it to do again I would have kept the LJ78 and just dealt with the engine issues as they arose.

I've read through almost every LJ78 thread on this forum, and have noted your conversations over the years with crushers. I did read how you ended up selling your LJ78 before you had problems. I know what you mean about not being able to relax with the 2LTE. It's starting to stress me out too. I'll take every precaution I can though, and just hope for the best. Hopefully I can get over it and just enjoy the truck.

skinnier tyres with a less aggressive pattern might be a good move.
for instance, if you stick the clutch in and freewheel, how long does it take you to come to a stop?
i had a permanent 4wd niva that wouldnt coast at all. the rolling resistance will affect your milage.
currently i have 7.50 R16 michelin xzl's on and i get excellent mileage for a mud tyre, but theyre less good at other stuff like rain.

on longer journeys it pays to keep the weight down and the revs high.

My tires are pretty skinny at only 235 (9.25") width. The OEM tires were 225, so they are really close. I still got bad fuel economy with the original little tires too. I'm auto, but if I put it in neutral and coast, the truck goes a long ways. Doesn't feel like the tires are slowing it much.

 

[Gun Runner 5]

I sold my LJ78 to someone in the Western part of the U.S. and lost track of it at that time. I assume the current owner is not a "mudder" because I have not received any inquiries or death threats. It would be interesting to know where it is today and if the current owner has had any issues.

 

[Radd Cruisers]

Another thing that comes to mind is a non-functiong (at least not properly) EFI temperature sensor.

It lives below the intake manifold towards the back of the engine - it has a green plug. Inexpensive to buy, a bit of a pain to replace due to the location in the vehicle.

In stock if you need one.

~John

 

[GTSSportCoupe]

Another thing that comes to mind is a non-functiong (at least not properly) EFI temperature sensor.

It lives below the intake manifold towards the back of the engine - it has a green plug. Inexpensive to buy, a bit of a pain to replace due to the location in the vehicle.

In stock if you need one.

~John

Great; thanks a lot John. I also heard back from Rob on the axle kit; thanks for that too.

 

[crushers]

i have had a couple and both were less than impressive for fuel economy and power. both were very strong engines.
and
almost everyone i have talked to have said the same thing.

25 mpg on a good day, 21 on a bad day.

think about it, you have a baby engine trying to move a heavy vehicle...

 

[GTSSportCoupe]

i have had a couple and both were less than impressive for fuel economy and power. both were very strong engines.
and
almost everyone i have talked to have said the same thing.

25 mpg on a good day, 21 on a bad day.

think about it, you have a baby engine trying to move a heavy vehicle...

If I could get in the 20's I'd be more than happy.

 

[crushers]

but they should be getting in the 30s with their displacement...

 

[Gun Runner 5]

I have always been told that you buy a diesel for the longevity and fuel economy. There are obviously some holes in that theory.

 

[roscoFJ73]

but I think I'm getting typical 6 cylinder gasser economy.

No ,its not that bad. A 3F can use 17/100 but is more likley to be closer to 20/100.
Timing belt fitment is tricky on these so you may well have one that is one tooth off.

Is it an auto or manual?

 

[GTSSportCoupe]

No ,its not that bad. A 3F can use 17/100 but is more likley to be closer to 20/100.
Timing belt fitment is tricky on these so you may well have one that is one tooth off.

Is it an auto or manual?

Ouch! OK, glad I don't have a 3F then.

It's an auto.