96 5.2 falls on face above 3000 rpm

H

hiflyer746

New member
Even in first gear it won't go above 3000-3500 rpm and has absolutely no power. At about the time it falls on its face the synominous sound of lifter tapping is audible. Plugs look decent. Fuel pressure is 50 psi. Compressions are erratic. While reading. . . sometimes the needle will just drop off like a valve didn't close. stable readings around 120 to 180. 175K on the motor. Didn't see any broken valve springs. Wondering how much a clogged cat would affect this. I'm thinking this is it. . . but definitely some issues in the valve train as well. Any thoughts?
Timmy
 

So further testing shows that throttle position has an affect on when the motor looses power. The higher the throttle position. . . the sooner it falls on its face. if I lightly accelerate in first gear it will go to about 3800 and stop. . . press down the accelerator and it decelerates. Sounds like the engine is fighting itself. Kinda pointing me towards the cat being clogged. Its at full throttle when the valve train starts to make a racket. so. . . thoughts?
Timmy
 
Well it was the CAT. So if these symptoms are yours, don't feel like you might be wasting your time by removing the cat. I just wish there was a better way of testing it without having to remove it.
Timmy
 
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