I have an '87 300E, 113,000 miles. After driving it for a couple of miles or so and stopping at a signal the engine goes into a rough idle mode and then doesn't want to accelerate, but sooner or later it seems to kick in so to speak. The rough idle doesn't seem to stop regardless of the position of accelerator or if I put it in neutral, etc. The temp gauge reads fine, oil pressure is fine too. This is getting pretty aggravating and a nuisance to drivers behind me as I crawl away from the signal going 5 mph. Had a tune-up several weeks ago, vacuum hoses appear okay too. Thanks in advance for any input.