Re: [T3] My tune-up and 2 questions

["Jim Adney" <jadney@vwtype3.org>]

On 16 Aug 00, at 12:19, Fuhriman, Mark wrote:

> Checked voltage at the fuse block, measured just 13V at medium rpm.
> Replaced voltage regulator (it looks original) with a spare (hecho en
> Mexico), now I see ~13.5-14V.  So I am expecting that to help my gas
> mileage.

Yes.

> Next, I adjusted the valves.  PO told me he had been setting them to .005"
> all around.  I changed them to .004 (intake) / .006 (exhaust).

Your way is better.

> Plugs looked good, but just a little sooty, probably because I had been
> running a bit rich.  I cleaned them up a little with a popsicle stick and
> put them back.

They will probably look better next time you look at them, as long 
as the engine is not missing. If it is, you will feel it.

> I replaced the dist. cap and rotor.  Points looked good, and dwell was right
> on with virtually no change with changes in rpm.

Bosch caps and rotors seldom fail or need replacement.

> Checked idle: measured about 950 rpm.  Bentley suggests 850 rpm for my MT,
> but the idle adjustment screw is screwed all the way in, and I can't get it
> any lower.  **QUESTION:** Is there something else out of whack if I can not
> get my idle lower than 950 rpm with the idle screw all the way in??

There is probably a vacuum leak somewhere. You should check 
your hoses, but this is not a problem unless its the pressure 
sensor hose (would make everything run rich) or just one of the 
intake air runners (would make 1 cylinder run lean.)

It may be that the engine will now run at its normal temp, that is, 
hotter. This can allow hoses to conform and seal in time. You may 
notice that your idle speed slowly comes down over the next few 
weeks and this would be a good sign.

> Distributor:  Both spark advance mechanisms are good.  I checked the vacuum
> can with the suck-hose-hold-with-tongue trick and it held.  Greased the cam
> block with cam lube.

Good.

> Timing: With motor idling, I disconnected the vac. hose from the
> distributor, but the idle did not change when I did this.  I adjusted timing
> to 0 deg with the vac. hose off and plugged per Bentley.  **QUESTION:**
> Shouldn't the idle drop a little bit at idle when I disconnect the vac.
> hose?  I know the vac. advance unit and the little vac hose are good, so is
> there a vac. leak somewhere in the manifold connections?  Or somewhere else?
> I think I read somewhere that the vac. unit should retard the timing by
> about 7 deg at idle.  But I do not see this. 

In spite of Bentley's admonition to remove the vac hose at idle, 
there is no reason to do so since it does nothing at idle except on 
a 72, where the retard is in effect. If you want to confirm that this is 
all working, just suck on the hose with the engine running and 
you'll quickly hear the change.

Sounds like you have everything worked out pretty well. Nice goin'. 

;-)

-
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054

-------------------------------------------------------------------
List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org