All Fuel injectors leaking

Hey there. So I have a 1982 Rabbit convertible, with a 1.8L Cis engine code MX (Canadian). I just completely rebuilt the motor. I also changed the fuel filter, which I don't know how long was in there, but had caught some particles. Nothing alarming though.
It starts awesome cold, but takes a few cranks to start hot, and will smell like fuel. Both my dad, and ex highschool shop teacher said it seems like injectors.
 I pulled my injectors to test one at a time. All 4 will leaks drops, dripping about every 4 seconds, and continue to do so for a while. My question is, since all 4 leak, is if certainly the injectors? Or could it be something farther back. The air flow plate was in good shape.
Also, since injectors are about $250 for the cheapest set up here in Canada, is there any hope to clean them? Looking online I see most people say nay to cleaning a mk 1 injector. Why is that? Thank you very much.

Yes,  CLean the injectors first.

But you will  need a new set of o-rings.
1 maybe 2 cans of Berrymans  b12 cleaner

see: CIS Injector Cleaning, Seal and Holder Replacement

Once you know the Injector is clean and sprays correctly, then you can proceed to look further as in place all 4 injectors in a ball jar and watch the spray pattern to see if they are still leaking after the cleaning.

 

Ok, thank you very much. I look around for some B12. My injectors don't have hats, so I assume I just skip that step. I'll return with my results after giving them a nice cleaning!

I tried cleaning the old injectors. Didn't do anything. Got new injectors today, and they still leaked!!
Turned out to be the pressure plate rest position was too high. I lifted the plate and bent the pin down a bit, as per the Haynes manual, and no leaking now.
That solved that.