So my 85 500SEL has the common "rough idle" symptoms that is well documented in threads of this site.

I attribute my problem more to infrequent driving than anything else. She does not go out much in the winter, and I have a company car during the week (1985 with 115k - you do the math).

I have been using a bottle of Techron FI cleaner with any fillup before an extended road trip. The old girl is so appreciative and just loves the open road, that the idle problems disappear, transmission smooths out, and the ride is wonderful. But then I go back to my old routine and she starts grumbling again. This tells me that some new injectors would make a world of difference (no record of FI service in the books - 2nd owner).

My question (finally!!) is:

Would others continue with this magic elixer method, knowing I am lucky to put 5k miles on a year, or would you buck up and plan to replace injectors, seals and misc. fittings? My concern is that the persistent rough idle will make other parts wear out sooner. I know too - I would enjoy old blue even more. I am inclined to DIY (did this on my 72 280SE 4.5 with great success).

What do others think?