1986 Mercedes Benz 190e Problem Starting

1986 Mercedes Benz 190e 6 cyl Automatic 30,000 miles

I have a 1986 MB 190e. We had it garaged for about 10 years, had it brought back to life by some mechanics (changed out hoses, lots of other stuff). They got it back to life, but for the last 5 years, we've had intermittent trouble starting it.
On a cold start, or after having run already, the car often has trouble starting. We can get it started with about 3 tries at 3-5 seconds each on the starter and some play with the gas (it's fuel injected though), but it's a real pain, plus I cringe every time we hold down the starter that long. The mechanics can't figure it out (doesn't help that the only time the car acts nice is when it's in the mechanics). They checked the obvious things. Anyone have any ideas as to why this model might do this? Anyone have similar problems with this model/year?
Thanks!