I just installed a new walbro fuel pump, new filter and a check valve. I also just finished a rebuild on the motor due to a leaking oring behide the timing cover. All new pulleys,plugs and wires etc... So everything was running fine for a few 100 miles than I shipped the car to Denver. I than got a reflashed ecu map from eurocharged. Now the car has a issue holding 3,000 rpm to 4,000 in 1st 2nd and 3rd. The car idles fine and can rev and hold 3,000 plus with no issue. The fuel psi at the manifold is not moving and staying at 56 psi. My question is the walbro pump faulty and can't keep up when the supercharger kicks in or has something happened to my ecu when it was flashed or a air leak that I have found? Here is a link to my video https://drive.google.com/folder/d/0B...h0NzVtVDA/edit

 

According to what I just read...the only change was the tune. I would start there. "So everything was running fine for a few 100 miles, then I shipped the car to Denver. Where was the car running fine before you shipped the car to the "new elevation? The elevation will affect the tune....but it won't cause it to quit at 3-4k rpms... That could be the tune. Remember when you rev, it is limited to those rpms so not to damage the motor. Fuel pressure is holding steady, which it is supposed to do. Now, are you running a 61 or 62 pulley? If you are, you may not have enough pump. That is a big if though...as it should still run better until it runs lien and falls on it's face. PM me and we will talk.