Just sticking to fuel delivery faults it sounds like it's running lean on acceleration.

High control pressure, EHA not working, general lean running, carboned up valves (yep, it'll do it) can all cause these problems.

If you have terminal 3 in your diagnositic connector then check your lambda value first. 50% is normal for most engines but the 103 engine (which I presume you have) prefers to run at 30-40% (I put it on 35% during services), they run quite well at this mixture, 50% is too lean on acceleration from experience. You can check you EHA (if fitted) for operation by watching the lambda value fluctuate +-5%.

A can of carby cleaner down the intake on a hot engine will also help if you haven't done it in a while. Make sure you do it on a hot engine and try and keep the lowest rpms possible without stalling (to help saturate the carbon and make it break off the valves).

Give those 2 remedys a go since they are simple and don't require much in the way of tools.

__________________
Alex.

MB Tech
Sydney, Australia
Volvo 122S
W201 190D 2.5 manual
W202 C240
W203 C32