fuel pressure regulator ?

[5150]

my camaro started running a little rough at idle in drive, and started pinging on the the big end at about 4500 rpms. i checked the fuel pressure with the key on engine not running,it has about 50 psi. when i start it up it jumps to about 59 psi. i took the hose off the regulator while it was running and nothing changed. the haynes catalog states with key on 55 to 60 psi. engine running it should drop 3 to 10 psi. im pretty sure the reg is causing the rough idle could the fuel pump be getting tired also causing a lean mixture on the top end? the car has 82,000 miles on it. i run union 76, 91 octane all the time. my mods are mti air lid,magnaflow cb, k and n air filter, smooth bellows, fra, tb by pass, home ported and descreened maf. are the mods i have too much for the factory tunning? any help or ideas would be appreciated.

[5150]

incase anyone is intrested, i took the car to my buddys shop. he said the fuel pump is fine but he found a service bulletin from gm indicating a knock sensor problem. is what happens moisture gets trapped in the rear sensor cavity usually from people rinsing off their engines and causing corrosion to form around it therfore causing the sensor to work improporly and not pull enough timing out when the engine is under a load. that service bulletin number is 02-06-04-023a, this was also a problem with other vehicles. hoping my extended warranty i bought with the car is going to pay for it but we'll see. after the shop does the repair i'll let you guys know if that took care of it. oh ya as far as the rough idle, a bottle of stp in the gas tank smoothed it right out.

[SSJoe15]

Good to know. glad it worked out.