fuel injectors

[Steves LX]

A friend of mine just put together a P headed 302 for his 91 LX. He is running 19LB injectors. He keeps calling them phase 3 injectors or something like that. But anyways the problem is he says the car wants to cut out around 4500-5000 RPM's at 39 PSI fuel pressure. So he cranked it up and the car runs great now at 55 PSI. He said it doesn't smoke or nothing. So he backed it back down some and it started to cut out again. He is running a Holley 255LPH pump and a kirban AFPR. Anyone have any ideas why this is?

[kennebellcobra]

Might be to lean with 39 lbs and needs 55 to make the 19's keep up. Get a wideband on it to see what it's really doing;) You guys need to go in half on a lm1 or something you can switch from car to car. I would also make sure there are no vaccume leaks.