RE: [DML] More problems found (was Piston rings + sleeves)

["Dave Sontos" <dsontos@xxxxxxxxxxx>]

First off only perform vacuum checks when the engine is at full operating
temperature. 

With the engine off move the throttle slightly open and you should hear the
idle speed switch click closed. If you don't hear it click you may have to
adjust the screw on the throttle arm to engage the switch at the throttle
closed position. This switch shuts off the vacuum to the distributor at
idle. Correctly adjusted the engine idle should reduce to the 750-950 RPM
rate when the switch is engaged.

Check the ignition timing. It should be close to 13 degrees.

When was the last time the engine had a complete tuneup? (sparkplugs,
distributer cap, spark plug wires, rotor, replaced fuel injectors)

The vacuum line coming from the rear of the left side of the intake manifold
goes under the intake manifold to a thermo vacuum switch where it
distributes vacuum to the CPR and the distributor. At engine temperatures
below 104 degrees F the vacuum switch is open to the CPR valve to provide
fuel enrichment to the cold engine.

Dave Sontos
Vin 02573

-----Original Message-----
From: stainlessilusion [mailto:5n-@xxxxxxx] 
Sent: Friday, January 14, 2005 8:23 PM
To: dmcnews@xxxxxxxxxxxxxxx
Subject: [DML] More problems found (was Piston rings + sleeves)

Yes so I had a chance to check out a few things on my DeLorean today.
While I didn't get a chance to check out the compression yet- This is
what I come up with- first of all, when I push on the adjustment screw
for the idle speed sensor switch, the car idles lower-meaning that for
some reason the plates arent closing to give a slower idle. Bad
srpring? Secondly, when I take the vac line off of the distributor
advance and hold the accelerator at say 3-4 thousand RPMs, it is
smooth running, when I put the vac line back on, it is rough holding
any RPM. There is no vacuum in this line when the car is idling-which
is normal. Lastly, the CPR-there are 2 vacuum lines going to this, one
of which uses a delay valve, but both meet at a "T" fitting. I pulled
the main line off the "T" where it comes from underneith the manifold
and there is no vacuum at all, is this supposed to be? I checked this
out while the engine was both cold and warm. The vacuum line coming
from the back of the intake that goes to the barbs really isn't that
powerful-I'm not sure if this is normal or not. What really gets me is
the distributor advance deactivated-why would it clear up the running
of the engine-something wrong inside the distributor? I've been
driving this car for years with a bad advance unit and once I put one
in I've had this rough, vibrating running engine at any RPM. When the
engine is cold it runs extremely smooth, once warm is when I get all
the problems and hard starting. Likely my ported vac switch is bad??
Thanks for the help guys -----Dani B. #5003






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