What to do, what to do....

My own opinion:

Wait on changing the timing belt til next year, unless you drive many miles a year. Spend the time to find a very trustworthy Alfa mechanic who is skilled in the 164 timing belts. This is the big ticket item, and you want it right.

Check the suspension/steering to see what might have deteriorated. Might take new lower suspension arms, but that's not expensive (about $90 each or so, with new bushings), and you can do the replacement work yourself, if you have worked on cars before. You can also rebuild the struts, the large dia bearing has a tendency to bind and jump with a bang in turns if it gets very dirty. Lousy design. The tie rods last a long time. Check alignment (toe) front and rear.

Change plugs, and clean and use dielectric grease on every electrical connection in engine bay, including those under the air filter box. Haven't heard of the split hose problem much on the LS. Not expensive to fix, though.

Run on the winter tires until later. The new ones don't wear nearly as fast as the old versions.

Rust, you have rust? Oh yes, salty Detroit. Personally, I'd have the rust areas fixed before they become too much to handle.

Save your money if you plan on keeping an Alfa 164. Difficult to maintain such a car in your rust producing area if you are on a tight budget, and drive it all year.

It is more likely the stumble is not the timing belt being off, if the car has been running ok otherwise. Usually something else. I did forget to mention to start using some Techron or something similar. I've found that it does work, also proven by industry tests. I've used it once in a while for every one of my injected Alfas through the years, and have never had an injector problem. My 94LS runs very sweet at 95k miles.

I do think that these LS's are more prone to problems due to poor electrical connections, ie, connections getting dirty oxidized in the engine bay. Cleaning every connection in the engine bay with electrical cleaner and using dielectric grease seems to cure many problems people have thought are something more complicated.

Also, what plugs do you use? I use the NGK Iridiums for the LS. It's picky on plugs, and they can cause the stumble.

Better to try to solve a problem by getting the simple stuff out of the way first. Then, if all else fails, then try the belt timing.

I found that the Bosch plugs did not work well after a while in my 164S. I think Bosch got the heat range wrong for the plug they recommended. I would always get a miss or irregular throttle response in my 91S when the Bosch had just a few thousand miles on them. Looked ok, but the problem would go away upon replacement. I've always used NGK's in the LS. I buy my NGK BKR6EIX plugs at O'Reilly's Auto Parts. I'm sure there are others as well which probably work, at least for a while.

You won't be able to clean the "dizzy" as the LS doesn't have one, only the 91-93 164's. I found, for my 94, the ignition multiconnectors under the air filter box were extremely dirty due to their poor location, but once cleaned and protected with dielectric grease, a peculiar intermittent ignition cutout disappeared, and hasn't been a problem in years.

For the occasional "snapping" or shorting out of the coils on plugs, I lined the sparkplug hole and surrounding areas around the coils with insulating Mylar sheet. Worked like a champ, no longer hear any snapping.

I will repeat what I said about Techron, or other injector cleaners. I've never had an injector problem in any of my many Alfas, even with many thousands of miles on them, when using this cleaner once in a while.

Good luck on keeping your LS up and running correctly. I really enjoy my 94LS. I installed Koni shocks, aftermarket stabilizer bars, S springs, 45mm intakes, and 205/55-16 tires. It is a very nice high speed performer, taking it on long highway trips, such as to Galveston, Texas and back to Seattle, about 6k miles, what with visiting Nat Parks on the way. To Yellowstone and back was another fine trip. This spring, Banff/Jasper might be a fine place to revisit. Do have to visit San Diego for relatives as well.

We get about 28 mpg on the highway with the LS, driving about 80 mph most of the time (except for Oregon, which has really sucky absurd speed limits even out in the middle of nowhere, I really dislike that State in general), about 20-22 mpg in town. I use the 91S for almost all of my city driving. My wife screams around in her Shankle suspension equipped Milano.

Maybe the spark intensifier (amplifier)?

You have an LS. One of the specific problems the LS has in totally different from the other older 12 valve 164 cars is that it has computer triggered ignition firing. But the trigger impulse from the ECU unit is not enough to really give the necessary zap to the spark. There are two small spark amplifiers (each doing 3 plugs) attached to the inner lower edge of the air filter structure that step up the impulse. They get grungy and the contacts need cleaning. To check, try switching the leads from them and checking to see if it puts the miss on some other plug. It acts almost like what would happen if the car slipped a tooth or two on the timing belt at idle, but when going at higher rpm works just fine. That problem can be easily fixed by working (and prerhaps replacing) the spark amplifiers. If that cures the low speed miss you will have money to take care of the rest. REMEMBER THIS IS AN LS (24 VALVE) PROBLEM, NOT ONE ON BASE, L, OR S.

Yes, those amplifier multiconnectors are in a bad location, being exposed to dirt and water coming through the grill past the driver's side of the radiator. Mine were incredibly filthy, crudded up. took a while to make sure they were clean. I then made sure that they had enough dielectric grease to seal the plug-ins.

One note, early LS's had a plastic shield on that left side (driver's side) of the radiator similar to the one on the right, but I believe there was a note (bulletin?) to remove that one to prevent the modules from overheating and failing by letting more fresh cool air through. I took mine off, looked better with it on, but I don't want one of those modules to fail while out on the road. That then is how they can get cruddy if not sealed with the dielectric grease.

As Jay says, switching them to see if that moves the miss is ok, a good move, but in reinstalling the connectors, you might reestablish the connections perhaps temporarily, cutting though the crud. Then it is hard to tell what happened. The only cure is to clean those suckers. Then you will be able to also find out whether or not an amplifier is faulty.

I feel that all owners of the LS models should do a complete electrical connection cleanup in the engine bay of their cars before blaming anything else for a problem. It's a simple thing to do and it is then out of the way. It's all too easy to get led astray chasing a quirk or failure. I'm a firm believer in "lex parsimoniae", ie, Occam's Razor.

That's my put on it, anyway.