GM Forum - Buick, Cadillac, Olds, GMC & Pontiac chat

- Oldsmobile (https://www.gmforum.com/oldsmobile-171/)

- - No power, no codes (https://www.gmforum.com/oldsmobile-171/no-power-no-codes-314603/)

What carfixer007 said ^^^^^^^

. . . and/or watch the fuel pressure in the same conditions as you described above:

Quote:

Originally Posted by Pastorfox (Post 1646125)

It’s barely able to sustain 65 miles an hour on the interstate, especially going up a hill has to downshift just to hold it. Between 3 to 3500 RPM max and then it sounds like popcorn popping. Very doggy and weak.

Quote:

Originally Posted by carfixer007 (Post 1646248)

I think you ave a restricted exhaust or weak fuel pump. Check back pressure or just do this. Watch the fuel pressure while power braking. Keep it at converter stall until it starts running bad. Does the fuel pressure hold while the engine loses power? If so, it's a plugged exhaust. If not, the pump is bad.

this is most interesting because I didn’t put this in my information last night! When I gave the engine about half throttle, the fuel pressure actually went up to 50 and was jumping all around. Sounds like the exhaust is restricted. I think I’m going to pull the O2 sensor and see how it runs.