I'm working on an 84 760 GLE TurboDiesel. I want to adjust the barometric fuel control (like a Cummins aneroid) but I can't find any books or instructions.

Got it for $250 at a Junque for Jesus auction; goes like a scalded cat but puts out a black cloud when you stomp on it. I know this can be tuned out but need a manual or advice.

I've converted a couple of 240's to gas, but this one runs so nice I'd like to experiment with biodiesel, etc.

Any advice will be appreciated...

Thanx

You might want to sign up for the swedishbricks mailing list and post a message on there. Tomm Bryant, who posts on there, is very knowledgeable about Volvo diesels. link below:

www.swedishbricks.net/lists/home.html

I should have been more specific: The smoke only occurs when the accelerator is first floored. Holding the pedal down, the smoke clears up as soon as the turbo catches up. There is a barometric device on top of the fuel injector unit, with a hose to the manifold. I have never noticed this on a Dodge/Cummins. (That doesn't mean it wasn't there -- Where I worked with 2000 hp Cummins and Detroit diesels a little smoke from a pickup just wasn't significant!.)

Aha, what you really need is to go to the library or bookseller and get a copy of the "Bosch Automotive Handbook" a blue paperback sized book that includes a detailed description of the design of the VE pumps and components, also has a nifty bunch of other info. With your background and skills, you should have no problem tweaking and after tweaking, no problems. My answer was for those just learning high rev VW diesel peculiarities. Happy clear rattling!
PS Don't blame me if you get engrossed in the book, it's lots of neat stuff.

Another suggestion sent me to a VW diesel board, where I found a lot of knowledge. But the Bosch book you recomended is just what I was looking for.
Thanks

That is not a barometric device (which would be vented to atmosphere), it is a fuel enrichment diaphragm that causes a higher fuel limit when there is boost. Before boost is created, that valve is off and the pump acts as if there was no turbo and max fuel is limited accordingly.

The limit screw is adjusted for normal boost at full load. You didn't have to be more specific - as the symptom you have is common when injector spray is poor.

Once the pump limit is adjusted to the engine's maximum air intake (displacement and boost pressure), it should not need adjustment for the life of the engine. It is not a normal service adjustment. Guess why they sealed the screw at the factory.

Right -- the seal is gone on this one; one reason why I thought it may be out of adjustment. I have seen the device called a fuel limiter and an aneroid. It responds to increased boost in the manifold and raises the maximum fuel delivery accordingly.

As for the symptom, the smoke clears up as the boost catches up. That's why I suspected the limiter. I will run several rounds of fuel system cleaner through it and change the filter before I adjust anything.

Interestingly, I read a TSB from VW/Audi that says a clogged fuel filter will cause cavitation in the pump which will in turn cause incorrect timing, giving a smoke problem. I would have expected a clogged fuel filter to cause a fuel deprivation and no smoke...

With both a 1.5VW and D24T Volvo, the first thing I do with excessive black smoke is a quart of Techron in about 5 gallons of diesel through the fuel system to clean up the injectors. After that, Diesel Keene or Stanadyne additives. Black smoke is fuel not completely burned during the stroke caused either by overfueling under load or by the worse problem of dirty injectors not properly misting in the spray pattern. Also, pull or check the pellet in the ait intake filter box, just like on the gas models, the warmup air control causes problems.

There is an adjustment for max fuel delivery, and it is adjusted for just a trace of smoke under load, but it has nothing to do with the aneroid or boost diaphragm. Be aware that anything causing poor combustion, such as a dirty injector, will cause black smoke even when fuel volume is not excessive. All malfunctions, including injector timing, need to be correct before you can properly set the injection limiter.

Any idea where to find a reference manual? I've been a diesel and heavy equipment mechanic since '67, but never ran into many Audi diesels...

If you cannot find one at a public library (reference section 629.xx) like a 1983-6 Motor's or Chiltons covering VW or Volvo, you should be able to find this adjustment on other Bosch VE equipped engines such as Dodge/Cummins.

The limit adjustment is a locknutted screw that goes into the injector housing and probably sealed with a crimped tin collar. Adjust only 1/8 turn at a time. CCW to reduce smoke. If it appears tampered, then maybe adjustment was played with. If still sealed, fix what's really wrong because adjustment will only cover up the problem, not cure it.

Is the cold start device working properly? It's a wax filled thermal do-dad with two coolant hoses leading to it. The little cable should be pulling the ferrule when cold, for advanced timing and raised idle speed, and have slight slack after warmup.

Yes, the cold-start device seems to be OK. I've seen these fail, but this one is working. I haven't checked the timing yet. I made a tool once, but I'll have to find it or make another. Meanwhile, I seem to have some sort of problem with the ZF transmission. Shift speeds are high even though it looks like the kickdown adjustment is proper (I haven't actually checked it, just looking at the crimped ferrule on the cable and its position vs the cable housing).