Hydraulic Valve Adjustment and Associated Noise - kinda long

vwlover77 · Post by **vwlover77** » Thu Sep 13, 2007 10:49 am

Strop wrote: However, I do not like the fact that the vacuum gauge reads a fluctuating 12 -14 until the engine has warmed up (from a cold start at idle with no pressing of the accelerator pedal - completely warming up "on its own" so to speak) about 10 minutes or so. Shouldn't I get 15 lbs immediately whether or not it is cold or hot? I cant find any vacuum leaks.

I don't think I'd be too worried about that. The idle rpm may be slightly lower after a cold start, which would reduce the vacuum level. Also, it may be that there is more leakage past the rings until the oil gets good and thin and the thermal expansion of all the engine parts takes place.

Strop · Post by **Strop** » Tue Oct 16, 2007 5:36 am

Well....

Adjusted 1 and 3 to 1/4 turn preload and now for the first time I have solid 130 lbs compression in all 4 cylinders and 15-17 in manifold vacuum at 900 rpm idle. Took a trip last weekend and cruised at 62 mph average and got about 144 miles out of 1/2 tank of gas. Power seemed good as well.

Now I have to figure out why it is running rich until it warms up.......... on the right track though...
=D>

vwlover77 · Post by **vwlover77** » Tue Oct 16, 2007 8:01 am

=D> Indeed!!! Good news!

You may want to replace the Temp Sensor II and see if it changes things during warmup.

Strop · Post by **Strop** » Tue Oct 16, 2007 9:28 am

vwlover77 wrote:=D> Indeed!!! Good news!

You may want to replace the Temp Sensor II and see if it changes things during warmup.

Ya know...I am thinking the same thing. However, I put a new one on when I had the engine rebuilt so it is only 2 years old. I am going to test it, then test the harness and ecu connections before replacing it though.

Did you ever get the cam situation rectified?

Post by **Amskeptic** » Tue Oct 16, 2007 6:02 pm

vwlover77 wrote:
reduce the vacuum level.
may be that there is more leakage past the rings until the oil gets good and thin and the thermal expansion of all the engine parts takes place.

Ah, nooOOO. Us armchair engineers. . . . .

Vacuum is created from the closed throttle plate on down to the cylinders. If the auxiliary air regulator is cracked open, you are getting air past the closed throttle, ergo! Lower vacuum. This is even true of a choke fast idle cracking open the throttle plate. And the dual carb buses with that central idling circuit will *never* see more than 10-12 in/hg at idle.
Colin anyways how 'bout them Indians?

vwlover77 · Post by **vwlover77** » Tue Oct 16, 2007 7:39 pm

GO Tribe!

chitwnvw · Post by **chitwnvw** » Tue Oct 16, 2007 8:57 pm

vwlover77 wrote:GO Tribe!

It hasn't even been 60 years since you won the darn thing. Patience my young Jedi.

Itinerant Air-Cooled

Itinerant Air-Cooled

Hydraulic Valve Adjustment and Associated Noise - kinda long