when i get on it. Why? I have done alot of performance parts on my car and it started running funny when i get on it a while ago. I would start it when its cold and i would try to drive off as it was very cold and my car would just die and would not start up again for like 15 minutes. I have a fuel pressure regulator with a guage on it and when i start it the guage says its at normal psi but then i drive it off right after and it dies then my guage says it has no pressure when i try to prime it by turning the key to the on position. when you start my car at first the rpms tick like normal when its turning over but when the guage on my regulator says no pressure my rpms dont tick either. That sounds like a fuel pump problem to me. And when im cruising on the highway at 70 and i give it harder gas the rpms will start to tick up (sometimes down, thats when my car starts to jerk and my car shuts off then backfires) But this only happens 50 percent of the time. But then i push the clutch in and its starts up.WHY?