Black Smoke issue

[Gunflint]

So I figured out my black smoke issue. At least it seems, so far. Here is my theory....

The symptoms I was having: The van was sluggish. It was running hot. It was spewing a fair amount of black smoke (which for a diesel generally means unburnt diesel particles, is my understanding...) particularly when the engine was under moderate to heavy loading.

I tried to run some injector cleaner through a tank of fuel, twice. No luck. Changed the fuel filter. No luck. Was planning to check the injection timing (actually have a diesel specialist check the injection timing...) Then I got to thinking about some things I had read about the EGR (exhaust gas recirculation) system on the auto versions of the 2CT engine. It seemed as if a lot of people had disconnected these. Mine, as far as I could tell, was still intact.

I disconnected the vacuum to the EGR actuator valve and sealed it off by folding the hose on itself and sealing it off with a couple of zip ties. I noticed an immediate difference. No black smoke, and the engine now performs waaaay better. It is my understanding that the EGR system is activated at low revs/idle to help reduce emissions. My theory is that once the valve was opened, it would stick open, essentially suffocating the engine. My deprived of oxygen little diesel was sluggish and spewing uncombusted diesel particles out of the tail pipe. It was also running hotter than usual. By disconnecting the EGR, it now has access to all of the oxygen it needs.

Retrospectively it makes sense. When I bought the van it ran great. I had a shop in town do quite a bit of work on the cooling system, recently, after hearing about all of the overheating issues these vans have. When I got the van back from that shop, is when the black smoke issue started. What I think happened is that the previous owner had disconnected the EGR long ago. When it was in the shop, recently, they must have noticed it was disconnected and thought they were doing me a favor by reconnecting it. Hence the issue. Just a theory, but it makes sense to me.

I hope this serves as a long term solution to the problem!!

Matt

[adamh]

My van was brought with the egr allready blanked, someone put alluminium gaskets both ends of the pipe, but left the pipe intact. In the inlet manifold when i removed it was coated in a thick tar like substance. all the re-circulated carbon and oil, i can take a guess. i think they removed the egr but did not clean the pipe, have to say its a job getting the manifold off without removing the diesel pump, which itself is of course located on the timing belt system. So, forgiveness for not removing the inlet manifold, mine was cleaned when i replaced a cylinder head.

Another point to mention if you replace your crank case breather (rocker cover to inlet ) pipe, make sure its not kinked, it will smoke out the exhaust.

[Gunflint]

Thanks Adam.

Yea I have considered in the future making blank off plates for the EGR. For now, she is running great and I am going to do my best just to enjoy her......we will see how long that lasts!!

Matt

[Ace MM]

It is my understanding that the EGR system is activated at low revs/idle to help reduce emissions. My theory is that once the valve was opened, it would stick open, essentially suffocating the engine. My deprived of oxygen little diesel was sluggish and spewing uncombusted diesel particles out of the tail pipe.

How's has been with it disconnected?
Curious if this is how you left yours

I've developed a little issue at 1900 to 2400 rpms.
If I don't go slow to 3rd (auto) it will smoke like a school bus until 2400.

I found a sticky diaphragm, sounds like a squishy wet shoe when opening or closing under quick throttle, on what I think is the EGR assembly. No noise if slowly actuated.
Vacuum disconnected from the manifold and plugged and issue is 98% resolved.
Will get into the diaphragm later this week.

Also: what are the adjusters for on many of these vacuum lines? 2 on the EGR.

[Gunflint]

Yep this is how I still have it. Seems to be working fine.

As far as the adjusters...I have no idea. Good luck and let us know what comes about!

-Matt

[Ace MM]

1 BB & and month later I reconnected it to stock and issue retuned immediately.

With it plugged, acceleration is almost enough to get out of the way and feels like it has 10HP more.
Mileage only 1MPG more or same