[Vwdiesel] Injection timing --(Hillbilly tuning 1980 to 86 Bosch )
James Hansen
jhsg at sasktel.net
Thu Mar 25 17:06:24 EST 2004
> Thanks for the warning. I've been wondering though - what about
> NA engines?
> Presumably there is a bit more room for error without the turbo
> producing all that
> extra heat (and power :-).
Some, yes. Black smoke or lack of it usually indicates your safety point.
If you are laying down a cloud and the heat gauge is climbing, back off.
It's a little motor, always safer to drop down a gear and let it whine,
rather than pull hard, smoke hard, top the hill fifteen seconds sooner, and
screw things up.
We will likely take the Jetta to the
> interior at Easter, which
> means several long hill climbs, something we don't see much of on
> the Island here.
> I'm a bit concerned that my timing by ear might produce
> unexpected side effects...
Personally, it would be a risk I am uncomfortable with. If I was on a long
trip by myself, no biggie. Car full of family, it's a bigger deal to me.
Same reason I run blizzak tires in winter. DOn't really need them, but the
safety margin with family on board is comforting. With timing, to err on
the conservative side and get there is better than to err on the wild side.
Best is to just time it properly in the first place.
>
> But, I have a gut feeling that it is still too far retarded, even
> though I have advanced
> it twice since changing the belt. It just doesn't seem to start
> as well as it did before
> the belt change. If I could find a dial gauge for a decent price,
> I'd do it the proper
> way, but I'm still looking.
Cold start behavior indicates proper timing in a very big way, so yes you
are thinking along the right lines. Centerpunch thickness or pencil line
movement at a time is cool.
>
> btw, I'm pretty sure the ticking noise I heard a while back is
> not valves tapping
> pistons (cam timing checked twice - ok), but instead a small
> exhaust leak which is
> very slowly getting worse. Possibly right at the manifold or
> downpipe - I just haven't
> had time to look yet.
Check your exhaust manifold bolts. Especially if you run synthetic or
semi-synth it has a way of encouraging the manifold to head bolts to work
loose just from the tiniest valve cover leak. Much more so if you overheat
the manifold on occasion. When I started to run synth in winter, my exhaust
manifold bolts started to work loose twice a year. First time I heard it, I
was just sick, thought I had pulled an exhaust stud or cracked the manifold.
This was on the high mile 89 jetta that had the heat set on high... er...
real high.
The noise is only noticeable under load at
> lower rpms - take
> foot off the pedal and it goes away. Does this sound like an exhaust leak?
It's still there, just gets more continuous, and the other racket drowns it
out, but yeah, you would swear it was a valve at first listen.
later
-James
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