B-diesel problem

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My 1978 BJ40 with B-diesel engine frequently has a lack of power. I was advised to change the diesel-fliter. Though is was worth the time & money because I learned about diesel engines, injection pumps and bleeding the system, it didn't solve the problem. :(
Second advise was to check the air inlet/outlet of the fuel tank. I noticed when I take off the fillplug of the tank there is a lot of vacuum, so the air inlet to the tank might be blocked. But where is the air inlet located?

Thanx, Ton
 
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I would assume diesels would be the same...
on a gasoline LC the gas cap is the vent into the gas tank.
So your next assignment is to get a new gas cap. :D
One (risky) way to tell is to either leave the gas cap loosely installed or test drive without the cap alltogether and see if it makes a difference.
 
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Drove about 15 minutes without tank cap; no problem. Put the cap back on. First 15 minutes no problem, then there it was again ... 50 kmph and no power to accelerate. This lasted for about a minute and then power was back.
Pulled the cap off again and drove another 20 minutes with no problem. Seems like the vacuum in the tank causes a lack of fuel. Or could there be another cause?

Ton
 

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[quote author=Ton link=board=1;threadid=9071;start=msg79244#msg79244 date=1072136495]
Hmmm, seems right to replace the gas cap, but I am not 100% convinced. Cruiser_guy said there's a vacuum in his tank, and before my problem started there was a vacuum in my tank too ...

Ton
[/quote]

I guess before I would start tearing anything apart, I would change out and verify the operation of the less-expensive items in a system first. So, surmising from your statement that there was no problem with the fuel cap removed, would that not make you question the conditon of the piece? Do you have anyone else around you that has a similar vehicle? If so, try their cap out, or go spend the 15 bucks on another cap, and keep it in the pocket, just in case.

Seems pretty striat forward to me...

Let us know how this turns out.

Good luck!

-Steve
 
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Ton! Ton! Ton! THE water sedimenter is a must for the diesel circuit ! Never leave home without it !

I found the water sedimenter (brother's 3B) completely clogged with sand and mud, filled to the top. I cleaned it and, got lucky, worked fine.

I would never recommend to run without it except in contengincy and sure that the fuel tank is clean. I would suspect that your B has a bypass BUT why the PO fitted a bypass is more questionable.

Engine Mechanical Diagnostic pages (EM-2, ... EM-10)

Is it the first time you deal with diesel?
Are you the Ton who has a 4runner?
 
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P.O.,
You make me worried about this. I didn't know the sedimeter was inoperative until I checked the fuel system a few days ago and found out there's only air in the sedimenter. Have been driving around like this since I own it (3 years)!
I will try to restore the sedimeter; it looks Ok from the outside.

Yes, this is my first diesel experience.
And no, I don't have a 4-runner.

Thanx,

Ton
 
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where is the hole or whatever in the cap? and is it a special vacuum release valve or something? Cause mine doesn't work either, there is allways a vacuum in the tank especially after long trips, but i dont seem to notice a power loss with it. And does the cap keep the dust out properly with the pressure equalising cap?

Sam
 

Ron

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we had some thing similar on our BJ ,so we checked every thing out the vent comes out just under the filler cap n the tank vents through the cap [its not a tight fit]
but our big problem was the return line back to the tank [it was squashed along the chassi] n the back up was slowing the fuel into the injector pump untill we started running then it was ok n if we stopped for a while we had the same thing again till we started moving then it was ok it seemed to equalise out ,we fixed the pipe n have not had any more problems
Ron
 
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[quote author=s79bj40 link=board=21;threadid=9071;start=msg80289#msg80289 date=1072361637]
where is the hole or whatever in the cap? and is it a special vacuum release valve or something? Cause mine doesn't work either, there is allways a vacuum in the tank especially after long trips, but i dont seem to notice a power loss with it. And does the cap keep the dust out properly with the pressure equalising cap?
[/quote]
Sam, looks like there is a valve in the cap. A spring keeps the valve closed until there is pressure from the vacuum in the tank. Haven't discovered a hole in the cap; I guess the air goes through the keyhole.
If you don't suffer lack of power, don't bother about (some) vacuum in the tank; seems pretty normal.

Ton
 
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[quote author=Ron link=board=21;threadid=9071;start=msg81503#msg81503 date=1072714657]
but our big problem was the return line back to the tank [it was squashed along the chassi]
[/quote]

Ron, thanx for the tip. Haven't inspected the return line yet, but will look into that. I am checking everything in the fuel system and correcting everything that seems faulty.

Ton
 
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My sedimenter on BJ42 from NZ was by passed too, I checked it for leaks , cleaned it out 3x times and reinstalled it,seems to be fine ?? Why do people bypass this needed item???
 
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BJ40s sold by Toyota to Australia and NZ were not sold with any sedimentors fitted to my knowledge. (Mine definitely left the factory in Japan with the only sign of a sedimentor being the unconnected connectors for it in the wiring harness.)


Edit 20 June 08 ----- Discussions on MUD have revealed to me that some BJ4#s sold new in New Zealand were indeed fitted with sedimenters!!

As far as vacuum in the fuel tank is concerned. - That has always been normal for mine.

I know of no "fuel return" line to the tank on my vehicle. There is just one supply line running along the LH chassis rail to the fuel pump/primer. However there are some complicated venting lines between the filler and the tank itself that I have never fathomed out. (Never had the need to try.) You can see them if you remove that little plate in front of the RH rear wheel (inside the wheel arch) near the fuel filler location.
 
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holy dig from the past, I'm with my NZ friend on this one, there is a breather that runs down the piller in front of the wheel arch from the filler neck assembly and vents to the atmosphere (only noticed it recently and assume it is factory). With the "B" having the return line going to the inlet side of the primer pump, works the same as having a return line going back to the tank, just with less connectons to suck air from
 
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My 1978 BJ40 with B-diesel engine frequently has a lack of power. I was advised to change the diesel-fliter. Though is was worth the time & money because I learned about diesel engines, injection pumps and bleeding the system, it didn't solve the problem. :(
Second advise was to check the air inlet/outlet of the fuel tank. I noticed when I take off the fillplug of the tank there is a lot of vacuum, so the air inlet to the tank might be blocked. But where is the air inlet located?

Thanx, Ton
Interesting to see this post again ... it's 4 years old! After all it had nothing to do with the fuel cap. The problem was a non airtight connection in the fuel return line.
I also know now my BJ40 has no water sedimenter; it never had. I guess Toyota didn't install water sedimenters for the european market.

Gr Ton
 

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