[Kirk911SC]

Background:

Car is an '82SC. Recently backdated the exhaust. SSIs, and MB911 muffler.

Recent (2 weeks ago) valve adjustment, and oil change by factory trained mechanic.

WUR replaced less than 2 months ago (old one was faulty). Pressures within specs too.

Less than 10,000 km on the following:

-Spark plugs (Bosch W5DC)
-Magnecore spark plug wires
-Rotor, and distributor cap
-Air filter
-Fuel filter


Ignition timing set to factory specs.

Problems:

Car had VERY bad exhaust backfiring after the SSI install on deceleration. Tracked down an exhaust leak and this seemed to reduce it slightly. I found that by disconnecting the vacuum retard on the distributor the backfiring was almost completely eliminated on deceleration (very slight now).

There is still a slight exhaust "chuff.......chuff" kind of muffled backfire/miss at idle. Too rich? Idle not as smooth as it could be. Seems to get a little worse once warmed up.

Also, after warmup the idle will sometimes come up about 400 rpm (to 1400) and stay there. Idles at 1000 normally.......doesn't start off high and decrease like it should. After sitting for an hour or so when hot, if the car is restarted it will idle very poorly and at a very low rpm (~500 or so). Will easily rev, and seems to drive okay. Never any problems starting the car......fires right up whether hot or cold.

The other thing is that the car doesn't really seem that much quicker after the install. Sounds great, and it revs much better, but.................

Does this sound like the mixture is causing my problems? I've tried to adjust it and seemed to have some success, but I can;t be sure.

Ideas?

Kirk