92' KA-DE Lack of Power and Hissing

[Thoughtful_One]

I've had this problem for a while. There seems to be a serious lack in power. It does pull, but only a little and only when driving for the first 20 mintues. After an hour or two, it def. does not pull. The car does rev over 2500 RPM. When this lack of power occurs, there is no difference between 1/4 throttle and WOT. I would even go to say that 1/4 throttle gets better repsonse than WOT. Also, when accelerating, I hear hissing or a "shhhh" sound. You can say that it sounds like a spooling turbo. What should I check? It had problems with running rich, but after the mech. repaired a wire on the MAF and replacing the O2 sensor, it doesn't anymore. Any suggestions?

[JeromeS13]

Check to see how much exhaust is coming out. It sounds like your cat is stopped up. Are you overheating at all?

[Thoughtful_One]

Check to see how much exhaust is coming out. It sounds like your cat is stopped up. Are you overheating at all?

How would I go about checking how much exhaust is coming out and what would I even compare it to? The temp. gauge has always remained constant (in the middle between the two extremes) no matter how hard I romp on the motor. Could the running rich condition in the past clog the cat? How would I even test this? What I don't understand is where the loud "shhhh" sound is coming from, or how it is even formed. Does anyone else have any ideas? Also, another poster had a similar problem with dimishing power, but I don't have a sound system, just stock factory speakers and a cd player.

[AmoebAssassin]

A turbo-like "shhhh" sound could possible indicate a vacuum leak, check your intake tract for damage. How does the car idle?

[OldmanPurdy]

Check to see how much exhaust is coming out. It sounds like your cat is stopped up. Are you overheating at all?

I would definatly check this, an engine running in a rich condition can ruin/clog a catalyitc converter over time. Just go to the muffler and have someone rev the engine and see how much exhaust is flowing out, its difficult to explain how much should be coming out but if your cat is really messed up it should be somewhat obvious. Good Luck!

[Thoughtful_One]

When I cleaned my throttle body a few months ago, I made sure to check the tracting and all was well and in good shape. The idle is so-so. It used to be very bad, but that was due to a MAF problem. The idle really stabilized after that was fixed, but it still idles high (900 RPM). It's strange becuase sometimes the idle will drop to ~720 RPM and stay there, even if I blip the throttle. But then sometimes when I do that it will go back up to 900 and stay there. And yes, I did try adjusting the idlle using the screw on the intake manifold. I even turned it all the way and the idle dropped only very slightly, but the car should've probably cut-out. I tried getting to the IACV to clean it awhile ago but I can barely fit one hand in there.

[Thoughtful_One]

I will try this, I just need someone to sit in the car and I will post results.