Surging issues, hard starts, fuel smell... Fuel Pressure Regulator?
EDIT: Confirmed it was the Fuel Pressure Regulator. Removed the air box to see the FPR, removed the vacuum line and fuel dumped out of it. Primed the fuel pump and fuel came out of the FPR.
If you're having the same issues as me, test it by removing the vacuum line and priming the pump, if fuel comes out, it's time for a replacement. Also be sure to double check your plugs if you've been running it with a bad fuel pressure regulator as it would likely foul the plugs.
Been having misfire issues with my 03 VFR, it's dyno tuned PowerCommander6, it's catless (Delkevic exhaust) plus all the intake mods.
At idle you can hear a slight misfire and when going, it struggles a little bit when cold and when it's warm at midrange RPM it seems fine, if I rip the throttle, it's fine but when I'm higher RPM, in VTEC and slowly opening the throttle, it struggles pretty bad. Meanwhile, if I full on RIP through the RPM range, it doesn't bat an eye.
I ran injector cleaner (mechanic friend start there then check plugs) through it but it almost seem to make it worst.
This morning, it's 17°C out and I started the bike fine but quickly stalled it (my fault, was tired and let out the clutch too quick) because I was moving the bike. When I tried to restart the bike, it struggled HARD to the point I had to open the throttle to give it gas to start then it did start but quickly died when I let go of the throttle.
Am I correct in assuming the fuel pressure regulator is gone out of it? I can smell fuel from the exhaust as I brushed it off because of it doesn't have cats, little bit of black smoke, HARD to start when it's hot (100°C+ on the engine). I'll be pulling the plugs this weekend but I just want to know if anyone has had the same issue and can possibly confirm my suspicions.