So i have a 1989 iroc z camaro and last august i put a 1991 5.7 tuned port in, map system, manual trans... Now it is dieing on me all the time. It will do it at least once everytime i drive somewhere. If i put it into neutral and coast to a stop, most likely it will die (once it gets hot).. then tonight i was driving home and was coasting, reved it to about 4500 rpm then it died right after. did the same thing when i poped the hood and reved it.. Replaced the iac, map sensor, and o2 sensor. I also checked my tps voltage, looked good, checked injectors, they were in spec, fuel pressure looked good, exept when i would turn the key and it would "prime" the system, the pressure would go up to about 40, then go to 0 right after the pump stoped.... So i dont know if its something to do with fuel, ignition, or what.. Out of ideas.. i ordered a ALDL cable today so ill have that soon.. O also, i have been able to notice when its about to die, and there are times where i feel it about to die (steering wheel gets hard to turn) and i watch the rpms,, and it will idle really low for a second then either die or it wont. Its really wired.. (it usually dies right away though) ANY SUGESTIONS WOULD BE GREAT!!!!!! THANKS!!!!!!

if the pump stops and your pressure slams right back to 0, your injectors are probably shot. one or more of them are stuck open and just leaking the fuel right out. i had the same issue... and if your engine is getting large amounts of fuel pumped into it that would explain the stalling as well. mine was running like crap and had the same pressure bleed down issue as you (not as bad though) and i scored a set of rebuilt bosche type III injectors from Jon at FIC (http://fuelinjectorconnection.com/shop/index.php) and couldn't be happier. my idle straightened out, i didn't loose pressure when i shut the car off (even over night).. and my fuel economy even picked up noticeably.

Had a similar problem w/ my TPI motor, ended up being a worn out throttlebody blade shaft. Would run fine then die after warmed up intermittently. the shaft was worn, had play and would move causing problems. Just check and make sure that's not your problem????

Also check your fuel pressure regulator .

agreed... its either the fpr or the injectors. with your fuel dropping like that you have a bad leak and its either on the ground or one of those two components. after you resolve that issue, we can address the bad idle or other issues that may be caused by the throttle body

ok ill check it all, let you all know what i find.

so i checked the injectors and they are not leaking, so i will buy a new fpr and see what happens, hopefully thats it! ill let everyone know tomorrow. Thanks everyone for the help