Date: Sun, 08 Oct 95 23:31:26 PDT
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: Nick Pace <nickpace@rand.org>
Subject: VW-71 BUS-CHECKING FOR INTAKE MANIFOLD VACCUM LEAKS
First, I'd like to thank everyone who sent me advice regarding the amount
of advance on my vaccum advance & retard distributor. I was getting 44
degrees of total advance at 3000rpm (even with the idle timing set at TDC)
and based upon the number of messages from all of you screaming at me to
stop driving RIGHT NOW, I ran out and bought a .009 distributor. Total
advance now set at about 27 degrees at 3000rpm and about 5 BTDC at idle.
Again, thanks for all the suggestions and info. It makes all of this
Internet crap almost worthwhile.
Unfortunately, new newly rebuilt long block (1600 DP) is still not running
quite right in terms of power and cooling. It idles like a dream and the
acceleration from idle to warp speed is OK concidering the .009-34PICT3
combo's notorious deadspot. However, when going up hills and at normal
cruising speeds something is lagging. I'm in 3rd when I should be just
fine in 4th and my J.C. Whitney high temp idiot light comes on anytime
after I been running for a while and I starting slowing down. It almost
feels like I've got a fouled plug or the timing is wrong or I'm driving at
9000feet. The easy answers are not available since with the last two
weeks I've replaced or readjusted as follows:
*New distributor, points, condensor, plug wires, plugs
*New fuel pump
*New air filter
*Valves adjusted to .006
*Dwell is 50 degrees
*Timing is 5 BTDC at 900rpm and 27 BTDC at 3000rpm
*Plug gap set to .025. Plug color is a clean tan (though ring is black)
*Compression is 125lbs in all four
*Inductive timing light fires when sensor is placed on any of the four
wires
*Center wire from coil will jump an inch or more with a bright blue spark
*Carb float OK, Q&D (quick and dirty) cleaning done (opened up, jets and
all similar parts pulled, everything non-plastic/non-gasket soaked in carb
cleaner, jets checked to make sure open)
All of these latest checks or replacements had no effect on the lagging.
Unless the carb is defective in some non-obvious way, the only thing I can
think of is an air leak somewhere between the carb and the heads. I've
sprayed starting fluid at the base of the carb, the junction of the
manifold and the line to the brake booster, the little black thingamabob
on the line to the booster, the manifold boots, and the manifold/head
connection but I don't get any change in engine speed. And it has been my
experience that manifold leaks cause backfiring-like sounds when going
downhill in gear as well as rough running and rotten acceleration. I
don't have those symptoms but if it is a small leak, maybe it only comes
into play at high rpms.
However, when I was driving in some hills today, the Bus lagging and
smelling warm, I noticed that when I braked for a stoplight, the foot
pedal was stiff like you feel with the engine off. Went away and never
felt it again (the lagging continued, however). QUESTIONS:
1)Could it be a leak somewhere between the engine and the booster?
2) Is there an easy way to check the lines?
3) What if I were to disconnect the line out of the manifold, plug it and
the manifold outlet, and drive it to compare the change. WOULD THE BUS
BRAKE OK??? I understand that more foot pressure would be needed.
4) If there is a leak in the line, and I plug the outlet and let the Bus
idle, would the idle speed be faster/slower/same than if I had the
allegedly leaky line connected?
5) What is that little round connector on the vacuum line?
6) Any other suggestions about where my problem lies?
Thanks,
Nick
----------
Nicholas Michael Pace RAND 1700 Main St., Santa Monica, CA 90407
Nick_Pace@rand.org voice:310-393-0411 ext. 6176 fax:310-393-4818
