I recently came into a 450sl with 44,000 miles on it. The thing is a real dog which I credit to doing nothing other than sitting for the last 20 years. The acceleration improved after I ran a couple of tanks of gas (with injector cleaner) through it but it still has a problem with stumbling during warm up. I removed the warm up enrichment compensator and opened it up but did not see anything wrong with it. The person that I got the car from had a previous problem with the car starting when warm and a dealer adjusted "something" to make it work. It starts fine now when it is warm but misses and backfires before it is fully warmed up.

Can you give me a list of the things that I might look for in order to trouble shoot this problem? The car is basically unuseable right now and I know that bringing it to a dealer (last resort) will not be pleasant to my wallet. Appreciate any help that you can give.