there is a screw on top of the carb that i know adjusts the air fuel mixture. ive been trying to adjut it but there doesnt seem to be any difference in performance. what is the proper way to tell if its adjusted properly along with the 2 screws in the front of the carb

oh yeah its a stock qjet that was supposedly rebuilt before i bought the car


thanx in advance guys
romeo
86/ta

headers
open element filter
no emissions equipment
5 speed

 

A good place to start is to set the idle mixture screws (the two in front in the throttle body) at 7 turns out each.

Somewhere in the engine compartment near the AC/heater is a green plastic connector that doesn't go to anything. Connect the positive lead of a dwell meter to that connector, and with the engine warm and idling, adjust to about 30 degrees dwell on the 6 cyl scale. Change the setting a little, let it settle out before moving again.

By "no emissions equipment", I assume you mean the A.I.R. (and perhaps the cat) have been removed. Hopefully you still have the O2 sensor.

 

do u mean 7 complete 360 degree turns or 7 half turns?

and what if i dont have the o2 sensor. then whtll happen. how bout the screw on top? wht does that one do and how do i adjust it properly?

 

7 complete turns. Those screws have extremely fine threads, and do basically nothing; just set them to 7 turns out and forget them, and leave them alone from now on.

Without an oxygen sensor the computer will have no idea whether the mixture is lean or rich. It willl be totally unable to do its job, it will light the Check Engine light, set teh duty cycle to some fixed value that will never change no matter what you do or what the engine requires, and run some default program for the ignition timing that is at all times far from optimum. Either install one, or replace the entire computer-control system, because it's essentially disabled. It's like a blind person trying to drive if it doesn't have it.

I'd strongly recommend having one installed, rather than the other option. You can get a bung for it from Summit or Jeg's or your local speed shop, have an exhaust shop weld it in, put the sensor in it and hook it back up, and get your missing 5 to 7 mpg back.

If you've messed in any way with your carb, put it back just like it was, because nothing you've done was the right thing to do and has only made the problems worse. It will probably work just fine in OE trim when you get the system as a whole back functional again.