Why dose my engine cut out while driving

My engine will cut out for a second or two while driving. If stopped with the clutch disengaged, it dies and will take repeated trys to start. My fuel pressure is between 35 and 40 psi while running. When this happens the check engine lite goes on the out as it starts aganin. The only other thing I notice is that the speedo does not always read correct and in some cases moves very erratic. It is happing more frequent and makes it unreliable. Please HELP !
Ted