Date: Fri, 5 Mar 2004 19:45:20 -0600
Reply-To: "Warren.K.Lail-1" <wlail@OU.EDU>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Warren.K.Lail-1" <wlail@OU.EDU>
Subject: Timing Done - Idles Rough (Long)
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Hi all, and thanks to everyone who offered timing tips. I began a pmail with Ryan Press who was VERY helpful.
Ryan suggested the following method (I'm using a Craftsman Advance timing light with a dial on the end):
Hi Warren,
Well the advance method is kind of hard to explain. You have to actually rev up the engine while you look at the pulley with the strobe light.
This is due to the advance curve; it changes depending on RPM as well as load. You are loading the engine when you rev it up.
So with one hand you rev the engine (moving the throttle plate) and the other hand you aim the timing light at the engine, while holding the
trigger down. You don't hold the engine at a constant RPM, you rev it up and let it back down. I have found that if you start at 3000 or so RPM
when you rev it up it reaches max advance faster.
You then watch as you rev the engine and see when the pulley "freezes" and then you let the engine back to idle and adjust the distributor, so on and
so forth until you get the U mark to line up with the part in the case when the pulley "freezes".
So when you reach maximum advance, the mark on the pulley will totally stop moving (perceptibly, using the timing light.) This lets you know you are at maximum advance.
You do all of the above with everything hooked up and the engine warmed up. Also, I'll have to check, but I think on my pulley I was looking at the left-most notch. This is left with you facing the engine compartment from the rear of the van. Anyway it is the wider of the two. So you'll need to get a feel for when you have reached max advance. It's
pretty obvious once you do, the pulley does not look to be wobbling about but it looks like it is frozen in one spot.
Also I think the "factory" method is to set the timing at 2300 +/- 200 RPM. So you unplug the coolant sensor and I guess hold the throttle open
so it doesn't stall. You then hold it at 2300 RPM and set it to 5 deg BTDC. Also their spec of 3500 RPM for max advance seems incorrect; if you look at the advance curve you'll see it reaches max advance ONLY under significant load.
Let me know how it turns out or if you have any more questions.
Ryan<<
Me again. I warmed the engine to full operating temperature, and then tried to do this just as Ryan suggested, but I think I would have trouble chewing gum and walking at the same time . . . so I had a little trouble (this may be easier if there at two people working together - I was by myself). I finally used the second method that Ryan suggested as per the Bentley manual.
Bentley says unplug the coolant temp sensor. When I tried this before, the engine stalled. This time I kept the engine running with my right hand on the throttle, unplugged the sensor, grabbed the light and at 2500 rpm got the U-shaped notch to line up on the center of the case with my timing light dial set at 5 degrees BTDC. Then I reconnected the temp sensor and revved the engine to 3500 rpm and the reading was at about 38 degrees BTDC, just where Bentley says it ought to be. I then set the idle to 850 rpm, which seemed a little low to me because the engine was loping a little. When it set it to 900 it smoothed out reasonably well. So, timing is set and it is running better than at any point so far. However, it still surges a little when I drive down the road, particularly between 2,000 and 3,000 rpm. I'm stumped.
I'm also hearing a little clicking off of the left side of the engine, but it does not sound like a lifter. I'm hoping its a small exhaust leak. I'll investigate further tomorrow.
Hope this helps anyone having timing difficulties. Don't thank me, thank Ryan and Malcolm and everyone else who has participated in this endeavor.
Where would we be without this list???
Warren Lail
88 Westy "Billy Bones"
87 GL
Long John Silver said, "Before an hour's out, I'll stove in your old block house like a rum puncheon. Laugh, by thunder, laugh! Before an hour's out you'll laugh on the other side. Them that die'll be the lucky ones."
