I have a weird problem with my finish nailer and I am hoping someone can help me troubleshoot it. I have to pull the trigger 3 or more times before it will shoot (I run the air at 90 PSI) Don't laugh but the best way to describe it is: pfft, pfft, pfft, wham. I removed the back and did not see any foreign matter but I cleaned and oiled the piston and cylinder anyway. It did not help. I have not taken it apart any further because it doesn't seem like a trigger problem and I don't want to get that deep into disassembly unless I an reasonably sure it will help. TIA.