Black smoke?

[NewFrenchCarOwner]

Hi friends, i have a Citroen C5 HDi 2001 Exclusive.
I washed my engine bay today after a couple of hours i started the car everything was ok, i went put for a test run (the car was parked for 7 years and 8’ve bought it) so it started failing (it was ok before i washed the engine bay) the car wasn’t picking up speed it was limited to 2.500 rpms, and when it was shifting speeds black smoke was coming out (only on high rpms) so i popped the hood and found a injector plug loose, now the car is driving kinda normal but i have the black smoke and the engine sometimes sounds really rough and that particular diesel engine noise super loud.
Any recommendations?

[Datadogie]

How loose was the injector. Maybe, if too loose, the bouncing has damaged the seal at the bottom. Might be a good idea for a new kit.

[Doo]

Hi friends, i have a Citroen C5 HDi 2001 Exclusive.
I washed my engine bay today after a couple of hours i started the car everything was ok, i went put for a test run (the car was parked for 7 years and 8’ve bought it) so it started failing (it was ok before i washed the engine bay) the car wasn’t picking up speed it was limited to 2.500 rpms, and when it was shifting speeds black smoke was coming out (only on high rpms) so i popped the hood and found a injector plug loose, now the car is driving kinda normal but i have the black smoke and the engine sometimes sounds really rough and that particular diesel engine noise super loud.
Any recommendations?

Black smoke usually means too much fuel, not enough air...Look for loose or collapsed intercooler pipe or worse, a hole in the intercooler itself. If it's sat all that time it may have corroded and a blast from a pressure washer could have put a hole through it.

[NewFrenchCarOwner]

Thanks i will check it out