Since I bought my car, my idle has been a rock steady 12-1500 RPM, high, I know, but it didn't hurt anything, so I left it. Finally, last week, I checked for vac leaks and got none, no surges in power, nothing. Then, after poking and prodding, I realized the aftermarket cruise control unit on the car was keeping tension on the throttle body, I think it's called (I'm no good with these things... the names, I mean), and was keeping my idle high.

Today, I disconnected the cruise cable, and went to turn the car over. I turned it over and I got like 400 RPM idle, it was barely running, it was so low, when I gave it throttle, and let off, it died. So, I fiddled with that little screw jobber on top of the whole thing, turned it as far out as I could, until an o-ring started popping up, and that put my idle at about 700 RPM, a very unhappy 700 RPM, at that, and dropping as low as 500 after I let off the throttle.

What's more, I'm getting about 12.5 volts (according to the car's volt meter) at 700 RPM, and my throttle response is crap, about .25 seconds hesitation, I figure, based upon the song playing at the time. Also, right before it picks up, it drops out, like it's ready to die.

This one, I feel is a little out of my league, and after searching, I see it falls into multiple categories, but I have a feeling one is causing another.

Also, when I let off the gas, I notice a much sharper drop in engine speed, and when I shift, I'm actually having to apply a little gas, to bring it up to speed. Granted, I didn't exactly test drive it, because it's night and I'm at college right now. Tomorrow, I'll hopefully find some time for a test drive, and stuff, but right now I'm looking for some ideas on where to start.

Any help is great, folks.

Thanks

 

Oh yeah, 87 base. Header, test pipe, cat back are my only real mods.

 

I too have an 87 GXL, and at a stop light at night, with my blinker, stereo, headlights, and subwoofer on, my voltage will drop to 12 volts, and my gauge lights will dim a little bit. Is this something to be worried about?

 

So the voltage thing is most likely the alternator going down the crapper, as far as I know, it's original.

But what about when I let off my gas? It makes no sense... I haven't test driven it yet, I hope I will soon, if I can make a dent in some homework. I'm just baffled as to why it's just dropping out when I let off...