I'll give you a little backround. Built a 355 with a HSR vortec heads comp 268 cam and also has the dynamic efi ebl p4 ecu.
Got the car running and was running pretty good, driving it a bit around town but it was open headers. I decided to get the exhaust finished. Dropped it off running good got it back and it won't idle. Since then I've replaced the coil,O2 sensor,fuel filter,drained all the gas and put fresh gas in it,even sent the ecu back to ebl to get checked out and it's fine.
It will rev but as soon as I let off the gas it wants to die. How ever randomly yesterday I started it and it ran just as good as before. Shut it down and started it again and it was back to not idling.
Any help would be awesome I've been running in circles trying to figure this out for a week