82 SC not what it should be.

[Bill wjw]

Hi All
I replaced the injector inserts on my 82 SC last week. I did it with the engine in the car. I also replaced the spark plugs and am waiting for a new cap and rotor. Last spark plug change I put dielectric grease on the spark plug connectors. When replacing the plugs this time I found corrosion on the plugs and connectors. The plugs were not clean and the nice gray color they have always been and had sooty looking carbon deposits. I should add that before that spark plug change I had replaced the easy to get at, rear two inserts before finishing the rest last week. At that time the car seemed to run OK but would hunt at idle when warm.
I was hoping for improvement with this new tight fitting injector inserts. Instead the car just doesn't feel right. There is a slight miss and a stumbling feeling during acceleration that suddenly catches on with a burst of power after about a second. I also found that the small line from the decel valve was not connected to the cruse control as it should be. It was just tucked in the front of the engine and I can feel it is pulling a slight vacuum. With this line connected or plugged the engine hunts wildly on deceleration and usually dies at a stop sign. Unplugged as I assume it has been, the hunting is lessened considerably.
From searches I may conclude that fixing some to the vacuum leaks, the engine is now running too rich. What is the sense in having a Porsche that does not run like a Porsche. Where and what order should I proceed to correct what is wrong here?
Thanks in advance,
Bill

[theFONZ]

Before you order any parts, you need to ensure you don't have any vacuum leaks, and that your fuel pressures are correct. Do a search on vacuum testing, and follow the write-ups. Once the system is sealed, use a CIS fuel pressure tester to verify fuel pressures. After those are done, you will have learned much about the system, verified it is sealed and getting proper fuel pressures, and you can proceed to troubleshooting if it is still acting up.

[Paulporsche]

Aside from the above, try plugging the line that went to the decel valve. Is there any other vac line attached to the valve? Did you get this car just recently, and has that decel valve line always been disconnected?

I'm thinking you are right in your guess that the inserts have tightened up the vac leaks and the engine is now running rich, but as the Fonz says only the fuel pressure and vacuum leak tests can confirm. I would also get your exhaust analyzed for richness (CO%). I do my own setting for CO by feel, but I've owned CIS cars since 1978, and my 911 since 89, so I know how it feels @ different levels of richness. If you don't have this comfort level you should get it checked w/ an analyzer.

I would also make sure your distributor is advancing correctly.

Why you have corrosion on your plugs now, after using grease, I don't know. Has the car been out in the rain a lot? Are the boots of the plug wires sealing correctly? Are the wires OK? How old?

Bosch always recommends making sure ignition parts are in order before proceeding to CIS, so definitely check the wires and spark, and install the new cap and rotor.

Also check your O2 sensor/Lambda system. Is your dome light working? The 2 are interconnected.