I posted earlier concerning power problems with 03 Suburban 140k miles. I purchased a fuel pressure tester and question how to interpret the results. Its a 5.3 engine. With only switch on 42 lbs. With engine idling about 42. While doing about 50 on the road about 42lbs. Flooring it goes to 50 then back down to about 42. Shut engine off with switch off too it slowly creeps up from 42 until it stops at 50 and stays. If you turn switch back on goes to 42 and same if started. Any help appreciated, Thanks

 

sounds like a healthy pump