a tiny tiny gas, car drops rpms?

[custom89stang]

okay so i start my car, let it warm up at 1200rpms, then it drops (rough idle) to the normal 850 or W/E and i have my foot on the clutch and give it just a tiny tiny bit of gas and the RPMS drop to like 500 and it feels like its gonna die but it never does, then i give it a tiny tiny more bit of gas and everything is fine and rpms go right back up....i can do this conistantly, like....give it JUST tiny bit amount of gas to make it drop VERY low (and then the computer saves it or something everytime?)....... CURIOUSLY this goes away after the car is warm...ANY IDEA WHAT IT COULD BE DOING THIS? the EEC maybe?

 

[Dean85GT]

my carbed car does that all the time...Its just how it is LOL

 

[90mustangGT]

May had idle issues. Clean the TB and IAC. Run the engine to full operating temprature. Then disconnect the IAC and use the idle set screw to your desired idle, then set the TPS signal voltage to .99. Plug IAC back in, start car, let it idle a minute or two then see if the problem is fixed.

I had this issue with a 97 Ford Ranger 2.5 OHV the other day. The A/C would come one but after revved up a little it would shut off, a few seconds later the A/C compresor would kick on, then imediatly shut back off, I noticed the RPM's were dropping. After the other switches were checked, a coworker suggested to clean the TB, I did this and did the idle reset procedure as I mentioned, not only made the A/C work, but the truck ran much better (about as good as a 4 banger ranger could run).

 

[custom89stang]

thx

 

[Euphoric306]

i got a ? 90mustanggt.... where in that process do u shut off the car, and how do u set tps voltage (voltmeter of course), but what adjusts it?