[Vwdiesel] Hillbilly tuning --- ( the cold start knob ).

H . Hagar. h_hagar at prcn.org
Tue Apr 5 18:13:53 EDT 2005

When cold, the knob should make QUITE a diffference. When warm it 
should make a slight, almost barely imperceptable difference in the 
sharpness of the knock.  That's the way I use to check if the timing's 
correct.  If it makes NO difference then the timing is usually retarded.
This is on nearly NEW cars so it's unlikely they were all "bad."

Here we have a clssical situation --- where the STUDENT disaggrees with the

And ALL of you may learn something.    ----     if I am wrong ?   NO problemo.

Loren have you ever seen a case where the pulling made No difference 
and the Pump was no good ?.

Notice I did NOT say if it makes a difference the pump is NO good.

The timing piston is a simple hydraulic piston  working against a spring.
The only thing that moves that piston is the cam pressure and internal pump pressure.
Timing of the Pumps and so on has no effect on it. ----NONE.

So the scale test still prevail.     ------ if I take my sentimental trip around the USA
by the time I get back ----I expect the pull on the scale in idle to be more than 2 lbs.

As your pump wears the pressure and things deteriorate ---- and the spring stays the same
well then it will not help the cold start push the piston as much -----bingo   we have an
indication of the state of the pump.  -----Everything else being the same.

So the scale will move from 2 lbs to 20 lbs   where the pump has to be pulled. ?  ---RIGHT?
RIGHT?.--- bet yor sweet ass.

Say we get to 10 lbs ?    can we do anything before pulling the pump ?
Absolutely  ---read  Hillbilly Tuning very carefully ----- and you will se that
fuel regulator is adjustable and viscosity of the fuel is adjustable ---- and the
return spring pressure on timing piston can be changed  (reduced).

What has OLDER students going for them ?  ----experience ----lots and lots of experience.

So when you read archives notice that this group  is as spread out as  as from   18 to
76 ----- now that is what I call a SPEAD. ------and I say that is GOOD.

Lets get the young whippersnappers in NOW ---so that when they hit 76 ---they know something.

When you read this remember Loren is a mechanic ----I am NOT and never was.


PS : this one is MINE all mine : being wrong and speaking up is no shame --
BUT being right and NOT speaking up is.

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