Fuel Problem

Hi all,

I have a 1990 Caddy Mk 1 1.6 Diesel.  When I ease off the throttle, e.g at 15 mph in 2nd gear, the vehicle jerks as though I was pressing and depressing the accelerator pedal very quickly.  I suspect fuel starvation of some sort, and although I have had the injectors ultrasound cleaned it has not made any difference.  Could it be the the fuel pump or the fuel stop solenoid?  Has anyone come across this before and be able to offer any advice?

Thanks

Spanner 1957