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

["DMC Joe" <dmcjoe@xxxxxxx>]

Dave,

You are correct on all of your suggestions but I would like to add the
following concerning engine timing. 

To Dani B.; Dave is correct about checking the engine timing, but if it's
off, don't readjust it. The PRV-6 timing does not drift out of operating
range. If you're having problems with performance issues I would not suggest
to fool with the timing unless it was adjusted after the engine started
running poorly. Here is an example. Over the years I have found that the
factory setting of the timing will remain within 2 degrees of the specified
+/-13 degrees even in cars that are receiving post 75k mile tune up's.   

DMC Joe

-----Original Message-----
From: Dave Sontos [mailto:dsontos@xxxxxxxxxxx] 
Sent: Saturday, January 15, 2005 9:34 AM
To: dmcnews@xxxxxxxxxxxxxxx
Subject: RE: [DML] More problems found (was Piston rings + sleeves)



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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