Check with key on engine off it should be 62psi it may be a bad regulator. Are you sure there are no codes? If the timing is going negative and I don't know how you can see that without a scanner, then it may be poor gas making the engine knock and it's retarding the timing. Fuel pressure at idle should be 65-71 so I'm not gonna say a pound off is bad but see what it is with engine off also check vacuum at intake at idle if 15" or below suspect a clogged converter/exhaust.
Wednesday, July 29th, 2015 AT 2:07 PM