BJ60 - poor mpg. (1 Viewer)

Joined
Oct 31, 2008
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South Shore of Montreal
Hi guys, few months ago I bought a LC BJ60 - 1985 - 3B - manual w/ h55f. The truck seems to be in good shape, only little rust, the engine runs smooth, no toc toc, strange noises or anything like that, no smoke at all, well a bunch of smoke on starting when it gets really cold (-30 celsius or so) but still after 2-3 minutes everything becomes normal.

But since I have it (mid-november 2008) I'm getting a really high fuel consumption.

- When the hubs are locked, driving in 4x4 high range, city driving, I can go up to 22L/100km.

- When the hubs are free, no 4x4, highway driving, I still get over 17L/100km...

In more or less 2 months, the lower fuel consumption I had was around 16.5L/100km.

Moreover:

- I drive like an old grandfather, slow and steady, 90km/h on the highway, I never make it rev too much (2500rpm at max).

- Everytime I put fuel, as i'm putting ULSD, I put some Cetane/Antifreeze additive.

- I run 5w40 synthetic oil. (3 000km since last oil change). the engine doesn't burn oil.

- the coolant is new (green one), the temperature of the engine is steady at 190 fahrenheit when the engine warms up.

- The air filter can't be cleaner than what it is. (I have a K&N air filter)

- The fuel filter is almost new (and I have no lack of power or anything irregular regarding this point.)

- the previous owner told me that the injectors were checked not a long time ago (1 or 2 years).

- I double check to see if my speedometer is wrong (I'm runing 31" tires). It seems to be right, I checked it with a friend running at 90km/h on the highway beside of me. I also checked with a gps and everything seems to be ok. I heard that sometime, on this kind of truck, the speedometer goes on and off, so I mesured the milleage that I get on a 100km trip with my other (new) car and compared it with mine, they are similar.

- no leak at all (oil, fuel, coolant, etc.).

I've seen my mechanic about this problem and he told me that the diaphragm seems to be a bit old, I changed it. Now I have a better acceleration (but I still feel like I'm driving a tractor, no worries, I like this feeling), but the fuel consumption is still the same.

Maybe it's winter? Well, it's still really high, no? Is it a hoax when people claim to have something between 8 to 12L/100km (most of the time around 9L/100km)?

My next step will be to bring my injectors to an injection shop to test them and maybe rebuild them.

Anyone as an idea of where the problem can come from?

- The only other thing that can make a difference is that the fuel/water separator (sedimenter) was removed.
 
Last edited:
Joined
Sep 6, 2002
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yes, that is terrible milage, about 13.5 mpg on the highway. it should be closer to 24.

Is there any black smoke upon acceleration? you could be running super rich.

any leaks at all anywhere? no drips under the truck when you park it?

The injectors could be completely shot, but you would get black smoke too.

removing the separator will allow water to get to the injectors, which will eventually kill them.

I don't have great advice, it seems like you are doing the right things.
j
 
Joined
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I edited the title to make it a little clearer. I thought you were going to tell us your BJ60 got better mileage than a Prius or something.

Higher l/100km is the same as worse or lower MPG. You want the l/100km number to be low and the MPG number to be high.
 
Joined
Oct 31, 2008
Messages
8
Location
South Shore of Montreal
yes, that is terrible milage, about 13.5 mpg on the highway. it should be closer to 24.

Is there any black smoke upon acceleration? you could be running super rich.

any leaks at all anywhere? no drips under the truck when you park it?

The injectors could be completely shot, but you would get black smoke too.

removing the separator will allow water to get to the injectors, which will eventually kill them.

I don't have great advice, it seems like you are doing the right things.
j
Nop no smoke at all when the engine is warm. I heard good things about Racor fuel/water separator, are they easy to get here in Québec? Someone has any other suggestions for a fuel/water separator?

cruiser_guy, thanks for editting, my mistake! The day I'll have a better consumption than a Prius, I'll not share the solution with you guys, I'll sell it :p
 
Joined
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Nop no smoke at all when the engine is warm. I heard good things about Racor fuel/water separator, are they easy to get here in Québec? Someone has any other suggestions for a fuel/water separator?

cruiser_guy, thanks for editting, my mistake! The day I'll have a better consumption than a Prius, I'll not share the solution with you guys, I'll sell it :p
the separator is not the problem here. lack of it could cause your injectors to deteriorate, if you have bad fuel. But that is unlikely, as you get no smoke.
 
Joined
Mar 1, 2005
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2,089
 
although this isn't your issue... running a K&N on an engine that's built for relibility not performance... is stupid in my opinion!

If you are going to run it... keep it well oiled, and clean it from time to time... also prechargers are a good idea... keeps sand/dirt away from the filiment which can cause small holes that are obvious when you hold a clean K&N up to the light!

just something to keep in mind... not everyone agrees, but one thing is for sure K&N's don't last a lifetime... although they may last the life of the engine both 100 000km's worth!
 
Joined
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although this isn't your issue... running a K&N on an engine that's built for relibility not performance... is stupid in my opinion!

If you are going to run it... keep it well oiled, and clean it from time to time... also prechargers are a good idea... keeps sand/dirt away from the filiment which can cause small holes that are obvious when you hold a clean K&N up to the light!

just something to keep in mind... not everyone agrees, but one thing is for sure K&N's don't last a lifetime... although they may last the life of the engine both 100 000km's worth!
I have no opinions about K&N filters, I heard that they are good, and the truck came with this air filter, so I left it this way.
 
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Check the e-brake, a common source of dragging brakes. Park the truck on LEVEL ground and leave it in gear but WITHOUT the e-brake on. See if the bell cranks on each backing plate are pulled out from the backing plate (bad) or retracted with the small adjusting bolt thingy resting against the backing plate (good).

Let us know what you find.

Is your filter a K&N or a TRD filter? The K&N has much less filter media than a TRD but they look similar.
 
Joined
Nov 11, 2007
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Vancouver, BC
 
 
I gotta agree with cruiser_guys thinking, you must have some serious rolling resistance!
Dragging brakes, tight birfields, who knows?
Maybe try parking it in a level underground parking lot (just easier without snow) and pushing it forward and backward, first in 2wd hi in gearbox neutral with the hubs free, then with hubs locked, then in 4wd hi, then 4wd low (might not hurt to try it in transfercase neutral too). That should give you some idea if you are getting excessive rolling resistance from your drivetrain and where it might be. It should roll reasonably easy on the level.

I have noticed that at cold temperatures, with the hubs locked and in 4 high with the front knuckles packed full of grease (yeah, a knuckle job is in the offing) there is considerable rolling resistance, but only enough to bring me from 11 l/100km to 14 or 15 l/100km around town.
Bonne Chance!
 

MrMoMo

That's not rust, it's Canadian patina...
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+3 on dragging brakes. Jack the truck up and spin the tires by hand. they should not be hard to spin. After spinning it by hand, put the brakes on, then off - then spin by hand again. Do this on ALL 4. You may have a caliper sticking in the front. Also check tire pressure. I don't get great milage around town, but it's not that bad. When was the last time you changed the fuel filter - it could be plugged. you say you are driving like a grandpa - for speed - but is your foot on the floor to be able to do this? Are you maxing out the throttle? Winter diesel will drop you down a bit - but not that much!

Check any marine supply store for a racor water/fuel separator, they should have one.
 
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South Shore of Montreal
This morning I jacked the car wheel by wheel and tried all the possible options. Now I really think it's a brake dragging issue.

The results:

Front left:
- hub locked: Able to spin it with no resistance for about 5cm and then it blocks.
- hub free: spinning with no resistance at all.

Front right:
- hub locked or unlocked: not able to spin it at all even if I try really hard...

Rear left:
- No handbrake/no gear engaged: spinning free, a bit of friction but almost nothing (I don't feel it, but I can hear something "scratching").
- No handbrake/second gear engaged: Able to spin it for about 5cm and then it blocks. (same very little friction)
- Handbrake engaged: not able to spin it at all.

Rear right:
- Whatever the set-up I use, the wheel is spinning with no resistance at all - even when handbrake is engaged.

This weekend, I'll to do the same test with someone pressing the brake pedal to see how it goes.

When I bought the truck, the previous owner told me that I'll need to replace all the brakes soon. I added some brake fluid and everything seemed ok. Now I see that I'll need to do it as quick as possible.

I'll keep you up to date about the problem.
 
Joined
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Right front caliper seized.
Right rear brakes messed up (I'll assume the short ebrake cable skipped off the small bellcrank inside the drum as that has happened to me before).

Replace the front caliper and your mileage will likely improve right there.
 
Joined
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Right front caliper seized.
Right rear brakes messed up (I'll assume the short ebrake cable skipped off the small bellcrank inside the drum as that has happened to me before).

Replace the front caliper and your mileage will likely improve right there.
I agree-very nice analysis. chances are the rotors are shot too, if the brakes have been dragging for a while. and of course the pads.
 
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Check the brake lines, bad lines will cause the brakes to stick
Also a possibility. I'd disconnect the caliper from the hydralics and see if the piston will retract relatively easily with a "C" clamp. The force needed should be just slightly more than you could do with your thumbs if it is disconnected from the hydralic lines. If it is still connected then a "C" clamp with just a little force. If you need a wrench to turn the "C" clamp things are too tight (or your too weak :) ).
 
Joined
Jan 11, 2008
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Seattle
 
 
Hi guys, I have the same problem. 17 mpg vs 24-27 mpg. Engine idles smoothly has same power going over bridge. Compression on all cylinders 480 psi except one at 470 psi. New oil/oi filter and fuel filter. IF I pus 1-2 psi pressure on the fuel supply line from the fuel tank, should the line not leak air going to and into the injctor pump? If it does, does this indicate a leak along the fuel line or leak inside the injector pump?
 

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