nitrous / fuel question

Anybody have any idea if the fuel that just sits in front of the nitrous solenoid could/would get hot enough to cause issues? Seems like I get really consistent strong hits when the car is relatively cool, but if I've been driving a while & hit the nitrous it has a pretty good chance of sputtering and running bad... but then if I hit it again it's always better and sometimes fine again.... anybody have any ideas on this? The reason I think it's heat related is I'm not using any hard lines past the mechanical fuel pump, and had similar full throttle issues w/o the nitrous when the lines were ran over the intake, so I moved the lines for the carb and currently I've got the line run along the firewall to keep it away from the motor heat, but that fuel solenoid sits pretty much right over the water neck on the intake.... Hope thats enough info!