Vanagon 1.6 Diesel, Fuel Injection Pump Timing

[bear15]

Vanagon 1.6 Diesel, Fuel Injection Pump Timing

Does anyone have some easy step-by-step (maybe with some pictures) of how to advance the fuel injection pump timing on our 1982 vanagon diesel 1.6?

Many thanks for any help. Ed

[bugeye72]

I just went through this on my van when I changed the timing belt a few weeks ago. To do it you need a dial indicator and a threaded adaptor to fit into the plug in the end of the pump. Do you have this stuff, or were you just hoping to tweak it by ear? there are a bunch of folks who have posted videos on youtube for doing this. I looked at a bunch of them, and like you'd expect, some of them were horrible, and some were good.

The adjustment is made by slackening the bolts that hold the injector pump to its brackets, and then you rotate the pump to the point that gives the correct reading on your dial indicator with the engine at tdc. The process is a lot like rotating an ignition distributor to adjust timing on a gas engine. I also have a bentley manual, which had the specs I needed.

I realize that all of what I've said is pretty vague, but I don't have the book in front of me to give hard numbers. Hopefully, I've given you an idea of what you're getting into.

[?Waldo?]

This writeup is assuming you are changing the belt. If you are happy with the cam to crank timing and just want to adjust the pump timing, then you don't need to mess with the valve cover, cam lock, etc...

http://vincewaldon.com/index.php?option=com_content&task=view&id=24&Itemid=28

[bear15]

This link looks very helpful-- many thanks! Yes, I think all we need to do is advance the pump timing as we are getting white smoke out of the tail pipe.

Ed

[?Waldo?]

If this is a new symptom I would suspect air getting into the fuel.

[bear15]

yes, this is a new symptom. Where might the air be coming in from?

[?Waldo?]

Usually it is due to a restriction e.g. clogged fuel filter causing excessive vacuum in the fuel line. Regardless, you should have a clear fuel line between the fuel filter and injection pump so checking should be fairly easy.

[bear15]

We did also just add a new fuel filter and injectors. The fuel flow seems good. Could it be that we did not tighten something all the way?

Thanks, Ed

[?Waldo?]

Sure. It could also be the quality of the new injectors. White smoke could be a whole lot of things. Are there air bubbles in the clear line going to the injection pump?

[bear15]

No, I do not see any air bubbles.

[bear15]

Ok, before we try to adjust the injector pump timing, this is what we tried.
-No fuel bubbles in the fuel line.
-Double checked that all the nuts and bolts are tighten to specs.

What we did notice was that when the engine is idling and we pull the cold starting lever out (which advances the injection pump timing) the amount of smoke is greatly reduced and the engine runs smoother.

Would this make sense that the Injection Pump Timing needs to be advanced some? If yes, would that mean all we need to do is loosen the 4 bolts that hold the injection pump (3 in the front and 1 in the back) and slightly "rotate the top of the injection pump towards the engine?" I am thinking a 1/16 of an inch movement for starters and add another 1/16 etc. as necessary.

What do you think? Ed

[bugeye72]

I'm not the voice of a wide range of experience, but it sounds logical to me. Just go a little bit at a time. They get noisy when they're over advanced, so listen for that. The tools aren't expensive if you decide to go the book method. I think I paid $25 for the right dial indicator adaptor off of ebay, and used it with a cheap dial indicator that I already had on hand.

[bugeye72]

I'm not the voice of a wide range of experience, but it sounds logical to me. Just go a little bit at a time. They get noisy when they're over advanced, so listen for that. The tools aren't expensive if you decide to go the book method. I think I paid $25 for the right dial indicator adaptor off of ebay, and used it with a cheap dial indicator that I already had on hand.

[MarkWard]

If I owned a diesel powered vanagon like yours, I would own 3 tools. The cam lock, the pump pin and the dial indicator setup for timing the injection pump. You are welcome to take swings at your problem using your ear and the seat of your pants, but why not know what is actually happening?

The early diesels from time to time would smear the front crank sprocket keyway. The first indication was a changing pump timing.
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[?Waldo?]

I would use a utility knife to scribe a mark between the pump body and pump bracket before making any adjustment. That way you can return it to where it is currently set. If the new injectors have a higher break pressure than the old ones, then the timing will be retarded from where it was before the injector change. As you say, loosening the 4 bolts and rotating the top of the pump toward the engine advances the timing.

[bear15]

Thanks for the tip about scribing a mark-- that was very helpful. I could see how far I was advancing the timing. I think I have the injection pump timing set much better than it was. It starts quickly and the engine runs very smoothly with the cold starting lever in where it should be. When warm, and I pull the cold starting lever out, the engine does not run as smoothly.

One follow-up question. Although there is much less smoke coming from the exhaust then before I advanced the injector pump timing, I still see a small amount of light smoke.

Any ideas what might be causing this?

Many thanks, ed

[?Waldo?]

Does it smoke all the time or just when you floor it?

[Dampcamper]

And what color smoke?

[bear15]

Only when I step on it, it is a lighter gray.

[?Waldo?]

When the amount of fuel exceeds what can burn with the air in the combustion chamber, you first get light gray smoke. When it exceeds the air by a lot, you get black smoke. If the gray smoke offends, then either turn down the max fuel screw slightly or step a little less hard o the pedal.