BJ40 B motor plumes of black smoke. (1 Viewer)

[Neilo]

Hi Guys,
looking for a bit of advice.

My '79 BJ40 has recently developed a problem with excessive black exhaust smoke during a certain situation.

It seems the car will start fine first start of the day and run clean to wherever I may be heading. If I stop for a short time and resume my journey with a warm motor re-start, the black plumes of smoke will begin under any amount of acceleration.
The black plume disappears after a couple of kms and I do seem to be able to moderate the black smoke output by feathering the accelerator particularly on level/downhill stretches until it clears totally.

The motor has had reconditioned injectors about 12 months ago, injector pump diaphragm replaced about 18 months ago, air filter new about 12 months ago. I run a fuel additive (always have done) and fuel is from the same source as normal. This issue has only started the last few weeks and doesn't align with any work I've done on the car.

It appears from the colour of the smoke to be an overfueling issue?? Maybe the IP not freely operating??

I am about to run a bottle of the Liquid Moly Diesel purge through the system but before I go ahead thought I'd check with the knowledge base here for any advice.

Regards, Neil.

 

[OTBT]

I always thought that grey/white smoke indicated an over-fuel; and black smoke indicated something in the lubrication system. Having said that, how is your oil-pressure and oil level ? If it was my engine I would take off the pan, remove the glow-plugs, and have a look a the bottom-end (crank & Big End bearings).

Just my $0.02 ... Glenn

 

[roalco]

Black smoke is almost always a sign of too much fuel, or too little air (the same thing). The first thing I’d do is to check the air intake system, all the way from the inlet, through the inlet ducting, the air filter included. You may have picked up something that got sucked in and is flopping around and partially and intermittently blocking the air to the engine. That’s for a start.

 

[duncanrm]

I would check the condition of the two hoses from the throttle body to the governor housing on your injection pump.

 

[Neilo]

I would check the condition of the two hoses from the throttle body to the governor housing on your injection pump.

Thanks, new hoses with support spring inside about 12 months ago. However, I thought the push on fit was tight enough, I'm thinking I will add hose clamps for sure.

Black smoke is almost always a sign of too much fuel, or too little air (the same thing). The first thing I’d do is to check the air intake system, all the way from the inlet, through the inlet ducting, the air filter included. You may have picked up something that got sucked in and is flopping around and partially and intermittently blocking the air to the engine. That’s for a start.

Thanks, although I replaced air filter last service (about 4000kms ago), I'll pull apart and inspect.

 

[Neilo]

I always thought that grey/white smoke indicated an over-fuel; and black smoke indicated something in the lubrication system. Having said that, how is your oil-pressure and oil level ? If it was my engine I would take off the pan, remove the glow-plugs, and have a look a the bottom-end (crank & Big End bearings).

Just my $0.02 ... Glenn

Oil pressure and level are both fine thanks Glenn.

 

[OTBT]

I stand corrected - in my old age I often get confused about stuff. I have the same engine in my BJ40, and I have experienced something similar when my EDIC control arm was out of adjustment (just takes a tiny little bit). Try putting a light oil on the connection at the pump end ... maybe that will correct the issue. With a warm start, the EDIC may not over-inject as it does on a cold start. This is a mystery ...

 

[Neilo]

I stand corrected - in my old age I often get confused about stuff. I have the same engine in my BJ40, and I have experienced something similar when my EDIC control arm was out of adjustment (just takes a tiny little bit). Try putting a light oil on the connection at the pump end ... maybe that will correct the issue. With a warm start, the EDIC may not over-inject as it does on a cold start. This is a mystery ...

Thanks Glenn, I'll check and lube this connection

 

[DEADSALT]

sounds exactly like your EDIC is running in overinjection,

next time it your are billowing black, pull off the road, open the hood and disconnect the edic arm from back of the IP pump.

 

[Neilo]

sounds exactly like your EDIC is running in overinjection,

next time it your are billowing black, pull off the road, open the hood and disconnect the edic arm from back of the IP pump.

Good advice! I will definitely try that. Cheers, Neil

 

[Neilo]

OK. Thanks everyone for the input so far, really appreciated and I think we may be onto something.

Two things I have found which are probably significant.

1. EDIC connecting rod. When the engine was running the EDIC lever and the IP lever were not positioned inbetween the "drive position lines" engraved on the lever as described in the B repair manual. The lever position favoured the over injection position by a good amount. I was initially confused as there was loose piece of plastic floating around under the IP lever making it difficult to see the lines.
I read about this in one of lostmarbles posts from 2008.....

Glad you fixed it.

Mine used to have a bit of "thin black plastic sheeting" under that lever that was "getting all chewed up". So I removed it completely.
But even when it was getting "chewed", it still didn't seem to cause any malfunctions. (Perhaps I was just lucky.)

But I always keep that lever "well greased".

2. The IP lever (with the EDIC connecting rod disconnected) would return from the "stop" position to "drive" position very positively under spring pressure by the feel of things. The return from "overinjection" position to "drive" position was not positive at all and feels a little notchy..... I can feel a firm indent when the IP lever is in the run position and I would have to help the lever get there after physically moving it to the overinjection position. I don't know if this is normal or not.

I have lubricated all pivot points as best as I can without stripping anything down and greased the EDIC connecting rod pivot points. I have adjusted the EDIC connecting rod length to position the IP lever and the EDIC lever are between the engraved marks correctly.

When starting and stopping the engine now I cannot fault the position of the EDIC and IP levers in "run" position. I cannot work out from the engine repair manual if the IP lever "run' position is governed by vacuum when returning from the overinjection position? It certainly seems to go to the "run" position correctly after starting.
I will have to just take deadsalts' advice and pull over and take a look at the IP lever and make sure it's not in a slightly overfueled position.

Thanks again, this forum is so good for helping with these great cars.

 

[DEADSALT]

the EDIC is controlled by a 'fuel control relay' located above passenger kick vent, mounted on the outside of glovebox;
remove gently, open up tabs gently and assess, its a common area for H2O, (more so in BJ60's).

when you hit the key to start, you should hear a click from this relay, this click signals the EDIC to move the arm to 'OVERINJECT' (more fuel) briefly for starting.
(interesting to note - FSM says to mat the gas pedal upon start- i.e. open butterfly in throttle body fully/more air. Was news to me, but makes sense with more fuel)
once your B fires, the arm moves back to 'RUN',
when you turn key off the arm moves further back to 'STOP' (interrupts ground)

you should not be able to easily move IP lever manually from 'RUN' to 'OVERINJECT', ...even manually from 'RUN' to 'STOP' will test your fortitude to actually make the truck stall.



my advise to you was;

once your truck is running,
remove the EDIC arm from the IP, it will then be in the 'RUN' position.

If the black death of misspent diesel is mitigated then you need to adjust your EDIC arm accordingly.
if the black death of misspent diesel persists, then perhaps you need to turn your fuel down, assess diaphragm, injectors, IP etc.

post some pics.

 

[Neilo]

Thanks Deadsalt, understand what you're describing and will follow up.

I was moving the IP lever with the EDIC arm disconnected, engine not running, just to get a feel of how the IP lever moved through it's range. This is when I noticed the return from overinjection position back to drive position was not smooth.

The function of my EDIC system is exactly as you described above (great description thanks), after watching through many start cycles I'm confident that the EDIC motor and arm are moving as they should be. I just need to check, as you suggest, when the "rolling coal appears" what position we're in.

Thanks again for taking the time.

 

[roscoFJ73]

The function of my EDIC system is exactly as you described above

A lot of owners ditch them and go for a complete manual set up with a cable.

 

[Neilo]

Update.

So, I took the advice offered by you guys and think I have solved the issue.

Deadsalt suggested....

sounds exactly like your EDIC is running in overinjection,

next time it your are billowing black, pull off the road, open the hood and disconnect the edic arm from back of the IP pump.

I did pull over and open the bonnet during a billowing smoke episode and, sure enough, the EDIC arm was in the the start "overfuel" position. I stopped the engine, left it off for a minute or so and then had my wife re-start the engine while I watched the EDIC arm. This time the EDIC arm went through the correct sequence, start position to run position and no billowing black.

It appeared that an intermittent problem like this could be related to poor contacts in the electrical circuit of the EDIC system. I cleaned, de-oxidised and protective coated the plug pins of the EDIC motor plugs as a first step.

I'm happy to say that I have had no further repeats of the EDIC arm stuck in the overfuel position. I was intending to inspect the electrical connections in the ignition switch wiring but will leave that for now, cleaning the EDIC motor plug connections seems to have done the trick.

Thanks for the assistance everyone, much appreciated.

Cheers, Neil.

 

[roscoFJ73]

Thanks for coming back to end the story. Too many leave us hanging as soon as its fixed.

 

[Neilo]

Update.

The issue did in fact return.

I proceeded to remove edit motor as detailed in other posts on here, and clean/re-grease as required. Same issue...

Removed and inspect fuel relay. OK but issue remained.

Remove and test ignition switch. There it is.... an issue with the switch continuing to hold on to the start position intermittently. I used copious amounts of contact cleaner into the switches tiny openings and it appears to have solved the issue. Months now without a repeat. I also ordered a replacement switch that I haven't as yet fitted but it's there to go on when required.

Thanks for the help everyone.

Cheers, Neil.