Yes, or something else in the mixture control.

Either the fuel is spilled somewhere before it enters the engine
(look/smell for leaks in the fuel supply) - personally I had a leaking
EHA - or the engine gets too rich mixture, which should be detected by
the lambda sensor and corrected by the EHA via ECU.

It could also be as simple as a bad OVP relay (or blown fuse), causing
the injection to work in failsafe mode without ECU control. Look first
for this option.

OVP = Overvoltage protection (OVP relay is located behind plastic panel
behind battery)
EHA = Electrohydraulic actuator (located on backside of fuel
distributor under air filter)
ECU = Electronic Control Unit (located next to the OVP relay)