I have a 1986 Trans Am LG4 with K&N filter, 180* thermostat, and Jet Stage II com chip.

Here's the problem...

a while back, I was under heavy acceleration merging into traffic when the car just sort of "bogged down" and took a while to get up to speed. Ever since, my throttle response is VERY noticeably worse than before. Under acceleration, the car hesitates and then will lazily climb up in speed. When at interstate speeds and I floor it, again I get a lazy climb in speed.

I have since replaced the plugs and wires, distributor cap/rotor, replaced vacuum lines (though I could have missed something).

OH! The car also seems to be using a LOT more fuel than it used to, and I can't pass my emissions test (passed fine last year).

So my thinking is that my Q-Jet is screwed somehow. I have a reman replacement for it that I haven't yet taken the time to swap over and tune, etc.

Is there anything else that could possibly be causing this problem??

EDIT: I also should mention that nothing sounds out of the ordinary on the car. Just no power...

 

timing, clogged cat, but i bet the problem very well could be i nthe carb.

 

Accelerator pump, float level, mixture control solenoid, fuel filter, etc. Most of the likely suspects are in the carburetor. Fortunately, Rochesters are generally some of the most user-friendly carbs out there.

If you are using more fuel and notice a lack of performance, anything you do to remedy the problem could end up saving you some money. If you do replace the carb, make sure you take a few minutes to seal the metering well plugs on the bottom of the carb before you install it. Check the archives for the details. I think RB and 5-7Kid have both commented on that, as well as many others.

 

i was thinking clogged cat also.

but sounds like maybe the carb.

 

if it were a clogged cat, wouldn't the car idle rough and be hard to keep running? It idles just fine.

 

Check your ignition timing and if you can put your hands on a back pressure gauge that can be screwed in place of the o2 sensor this would aid in determining if the exhaust is stopping up by seeing if it has an excessive amount of back pressure. The exhaust could be partially closed up and still idle. Any check engine light,hope this helps