'97 960 Volvo rough idle

Our '97 960 has started running rough and has confused at least two
mechanics. The first one replaced the MAP sensor and one injector. The
second wanted to replace the ignition coils since they had small
cracks. I tested this out by replacing one coil on the cylinder with a
misfire - no change. He also checked the intake manifold for leaks and
found none. This guy is a Volvo specialist. I checked for intake leaks
with a spray can of injector cleaner; it seems to be leaking around the
first two (maybe three) intake manifold sleeves and other places. One
place that acts like it is leaking is under the intake manifold but I
don't know that there any vacuum lines under it. I would like to find a
vacuum diagram before I take the intake manifold off and replace the
sleeves.

Any ideas?

Gary

 

When in doubt, clean your throttle body.

 

My 96' 960 (130k) had the same problem. A code reader was used to
find..I had 2 coils (cracks) out and a leaky intake manifold. The coils
were easy to replace. The intake was fairly easy too. I left all of the
"sleeves" on and pulled the manifold back as far as it would go (about
1-2") cleaned the block as best I could, "slid" the new gasket in place
and she ran like new again. If you do the intake mani yourself make
sure you use a few extentions with a swivel and a socket.