Just wondering if anyone might have any idea why I lost mid throttle all the way to wot. I have replaced the throttle position sensor, cleaned the egr valve. no carbon blocking it this time. and have also checked the map sensor which checks as good. Fuel pressure is at 62 psi at idle and about 40 at wot. I have also replaced plugs wires cap and rotor since summer. I can cruise along fine but anything more then 1/3 throttle it falls flat on its face. I have also replaced the fuel filter. This is in a 94 blazer with a newer vortec v6 in place. Any help would be greatly appreciated. Thanks

 

Hmmm, what about a possible plugged exhaust system? You can check that with a vacuum guage or pull an oxgen sensor out temporarily to allow exhaust to escape easily and road test for power with the sensor out.
If anyone has a better idea, please correct me.

 

On a fuel injected system, isn't the fuel pressure supposed to stay pretty much constant? I think it's supposed to stay above the 60 mark, isn't it? Try a bottle of injector cleaner, maybe that'll help things a bit...

 

When was the last time you changed the fuel filter??? The fuel pressure should not drop that much...

 

Truck has new 2 1/2 inch exauhst from the y pipe back fuel filter replaced 3 monthes ago. but tps reading erradicly. belive problem might lay there.

 

try checking the IAC and the ACC those are known issues with throtle response issues.