Hi,

I've recently bought a 1991 300E 24 manual (Getrag (dog-leg")with 318.000kms (+/- 200.000 miles).
It's was in good working order, but since it only had done 2000 kms in 6 years I took it to my mechanic to do a full check-up! Basically changed all the oils and filters and spark plugs. The car runs great almost all the times!
But sometimes if I go for a while at steady speed (about 2000 rpm's in fifth) and accelerate gently the engine starts to hesitate/hiccup! If I give full throttle it hesitates for half a second and accelerates cleanly all the way to the red-line!!!
Sometimes while I'm accelerating hard the car seems to have a slipping clutch (wich it doesn't), i.e: the engine is revving, but the engine sound seems strained and the car takes a while to develop speed!

Any help/suggestion would be greatly appreciated!

Did your mechanic replace the fuel filter as well ?

Cheers,

Tend to concur....if it's happening at speed it does sound like it could be a fuel delivery problem, especially in light of the low miles.

Fuel filter should be replaced regardless, and you might want to try adding Techron prior to your next fill up.
This will clean any varnish build up from your injectors.

If the fuel delivery system checks out, the next logical area which causes problems at speed would be the primary ignition circuit.

You have a 24V, but is it an early version with the CIS-E injection or the later with the HFM?