I'm not familiar with ICD guns at all.... but if it's leaking down the barrel and it's a poppet gun (Mini's/Spyders), it's probably your cup seal. This is the part that the rammer/striker/hammer slams against to allow air to flow into the valve. This is really cheap to replace.
If it's a spool-valve gun (like Proto/Dye/DP guns) then it is more than likely a valve o-ring or your solenoid. Take your gun apart, look at all the o-rings on the bolt and check to see if there are ANY nicks/cracks/scratches on them. If there is, make sure you replace the affected o-ring(s). If there is nothing, lower your LPR as much as possible, re-oil the gun, re-assemble, and shoot it over the chrono. If you can't get up to a reasonable velocity without it leaking, it's likely your 'noid. There are some o-rings you could replace in the 'noid that might fix your problem, but unfortunately I've shot a blow-black my entire life, so that's where my advice ends
I imagine an ICD owner could help you out a little better.
2005 Prostock 'cocker w/ Evil Detonator, Dye Sticky grips, & clamping feedneck | 68/4500 tank w/ Centerflag reg. | eVLution 3
BACKUP: Spyder Fenix | Ricochet Rhino
Originally Posted by Coenen
It needs more drop forwards.