Help! 1979 BJ in trouble!

[Max Wilder]

Hi, I recently bought a 79 'B' engine Land Cruiser


Long Story:

I flew down to Florida to buy the thing, and it ran great. Started right up and ran smooth with no smoke, it was beautiful.

The odometer said '48850' and it's in kilometers, but it occurs to me that the odometer only goes up to XXXXX, so for all I know it could be 1 48850 or 648850

Anyway, I bought it, I drove it, all good so far. I took it to a mechanic and had him change the oil, grease the fittings, and check the fluids. All good. He said that the hoses, belts, and seals were 30 years old, but all in good shape and should last till I get home.

So, time to drive it home (Dallas, then Bentonville Arkansas).

I got started and made it about 500 miles running 70ish on the freeway, all smooth and comfy, but then I noticed getting off the highway to get gas that it was idling hot; the rpm's didn't drop down like they should. As I went on it became more and more evident, when I let off the gas or put it in neutral it idled fast and was getting rough. Before long there was some white smoke along with it.

When I hit 7 or 800 miles it was pretty bad, so I stopped to do something about it. When I let off the gas it runs fast and rough, and belches out a lot of white smoke. As soon as I push on the gas though it clears right up and runs smooth. I changed the fuel filter and the 4 fuel injectors cause I had all new ones in a box that came with it, but that didn't solve anything.

Now I've driven another 350 miles to a friend's house in Shreveport LA and the problem may be a little worse, but it looks about the same. It's also burned some oil over the last 3-400 miles.

so what can I do? Can I drive it the rest of the way home (another 350 miles)? Should I not? Who'll work on it anyway? Most mechanics I've asked won't touch it and the tractor service places won't either.



Short Story:

Runs smooth on the freeway, when I let of the gas it puts out white smoke.

Idles too fast and rough.

Brand new fuel filter, oil, and injectors, some oil is disappearing.



Conclusions:

I figure it has to be an 'injector pump' or a 'compression issue' although I couldn't tell you what that actually means.

Anything I can look for? Anything I can try? Any suggestions who to take it to?

And lastly:

Can I just drive it home or should I not?

 

[cruiser_guy]

I got started and made it about 500 miles running 70ish on the freeway, all smooth and comfy, but then I noticed getting off the highway to get gas that it was idling hot; the rpm's didn't drop down like they should. As I went on it became more and more evident, when I let off the gas or put it in neutral it idled fast and was getting rough. Before long there was some white smoke along with it.

70mph in a BJ40 is probably a little excessive. My guess is you overheated it and cracked the head. Are you losing coolant?

The "B" series is known to have the heads crack from overheating. Remember, you're driving a tractor NOT a Ferrari!!

 

[Max Wilder]

That may well be what it is, but I've watched the temp gauge carefully and it has never passed the little line.

I'ts like this:

L\ ______/__ /H

and I've never even gotten to that line in the middle. And I've been driving through 100 degree heat for 2 days now.

So could it have cracked without the temp gauge registering overheating (and yes the gauge does work)

and if that's my problem, can I still drive it the rest of the way without breaking anything? Or am I lucky to have made it this far?

And no I'm not losing coolant, at least not enough to notice. I have been checking.


Also, if it is a cracked head, where could I get a new one from? Any suggestions?

 

[RufusTheDufus]

Doesn't a torn diaphragm do the same type of thing?

 

[seapotato]

Doesn't a torn diaphragm do the same type of thing?

yep. smoke , high idle , or a baby...depending on the application.

 

[Max Wilder]

I've been checking more into it and I'm really thinking it's the diaphragm not the head.

I'm not losing coolant, the oil and the coolant are both clean. I think it is the fuel system.

Thanks a bunch for the input, I really appreciate it.

But can I drive it home? Where can I get a diaphragm? Can I find someone to replace it for me or is it something I can do in my shop?

 

[vinny tetravino]

diaphram is black smoke check to see if you are getting bubbles out of the filler tube in the rad res..... if so cracked head or maybe just head gasket

 

[Radd Cruisers]

diaphram is black smoke check to see if you are getting bubbles out of the filler tube in the rad res..... if so cracked head or maybe just head gasket

Nyet, diaphragm can be any colour you want it to be. Depends on fuel, temperature, altitude etc.

Usually it's gobs and gobs of bluish white smoke. Might be grey-ish as well. Idles high, uses lots of fuel etc.

~John

 

[cruiser_guy]

Is the coolant FULL in both the rad and to the fill line in the overflow tank?

Try running the heater for a bit to see if perhaps the heater is airlocked? If it is it'll appear to loose coolant as the air is vented out. It may take a couple of warm up/cool down cycles to get all the air out, and you want it ALL out.

If it is just a diaphragm then you likely won't hurt it driving home. If it's the head.....

 

[canucksafari]

I find that my naturally aspirated engine tends to run hotter at higher speed such as 70 mph. If I bring it back down to 55 mph, then the temp comes down. That is just because I am putting more fuel into it and making it work harder. You wouldn't notice it with the same engine with a turbo. I think you should fix the diaphragm and then see what your temps are like.

 

[Max Wilder]

Looking into the problem I've found that a vacuum hose off the back (cab side) of the DAC (altitude compensator right?) is just hanging down loose. Is it supposed to be hanging? If not, I can't find anyplace to plug it into. Could that be part of my problem?

And can anyone recommend a source for a new diaphragm?

 

[crushers]

my bet would be the diaphram but i have never seen one go that fast all at once...

 

[cruiser_guy]

Looking into the problem I've found that a vacuum hose off the back (cab side) of the DAC (altitude compensator right?) is just hanging down loose. Is it supposed to be hanging? If not, I can't find anyplace to plug it into. Could that be part of my problem?

And can anyone recommend a source for a new diaphragm?

The loose hose is most likely a major part of the problem.

A diaphragm, if that's your problem, should be readily available from a diesel specialty place Association of Diesel Specialists | Service Location

 

[RufusTheDufus]

my bet would be the diaphram but i have never seen one go that fast all at once...

Would 700 miles with the IP metering rack pushed way to one side accelerate a failure of a diaphragm?

 

[RufusTheDufus]

The loose hose is most likely a major part of the problem.

The hose of the altitude compensator is just vented to the atmosphere. It's not attached to a vacuum source.

 

[crushers]

highly doubtful

Would 700 miles with the IP metering rack pushed way to one side accelerate a failure of a diaphragm?

 

[cruiser_guy]

The hose of the altitude compensator is just vented to the atmosphere. It's not attached to a vacuum source.

OK, I don't have an HAC on any of my three 3B's. I know there are two hoses on the intake and they need to be connected at both ends.

 

[eleblanc]

Doesn't a torn diaphragm do the same type of thing?

Yep, change the diaphragm, that is what i would do first.

 

[lostmarbles]

Lovely BJ40 Gobo! I'm keen to see more photos when you finally get it home.

Is the coolant FULL in both the rad and to the fill line in the overflow tank?.......

Cruiserguy has a good point here in that people often assume their radiator is full of coolant just because there is plenty in the overflow bottle.

So if (once the engine is cold) you remove your radiator cap and confirm the level in there is fine ...... then I'd ignore all the talk here about "possible cracked head" and "overheating from doing 70mph in hot weather".

The hose of the altitude compensator is just vented to the atmosphere. It's not attached to a vacuum source.

Rufus has eliminated this.

So that leaves us with the diaphragm. And I'm not surprised about the failure. It's probably old. (Should be replaced at least every 100,000kms. And probably neglected too. (Should get a drop or two of neatsfoot oil every oil change.)

....A diaphragm, if that's your problem, should be readily available from a diesel specialty place Association of Diesel Specialists | Service Location

Yeah.... Should be easy to source from any diesel specialist.

Here's what your after:


Quote the Denso part number. It shouldn't be expensive.

And if you're going to fit it yourself - do a search here on "diaphragm replacement".

 

[lowenbrau]

Another vote for the diaphragm.