What exactly is the problem?
I had a problem with my car going like sh*t and even worse when hot. Very poor running, powerless frome time to time and even engine faliure light...
In my case it turned out to be water in the sparkplug holes. I just removed the inlet and the ignition leads. Then blew all the water out with "pressurized air". It runs perfectly now.
If the engine does not run worse when a injector connection is pulled out you may be on to something. If you remove the inlet check that all sparkplugs are tightened if they come loose (rare) it may cause similar problems. If no water, not the injectors, no loose sparkplugs all I can think of is iginition coils.