Stepper Motor. Is it needed

[Beaverseagle]

So my buddy upgraded his 86 CJ7 with a fuel injection kit and he gave me his old carb in case I needed a spare.  Well it was all shinny and new.  So after I did my ECM Test bypass, I figured why not throw it on and see what happens.

Well, I'm not getting any fuel is what is happening.  The new carb is identical to my stock 82 4.2L carb sans the stepper motor.

it's probably a newbie question, but is this why she's not getting any fuel?

[Amc1320]

Stepper motor could make it run lean, but not cut off all the gas. If your sure your getting gas to the carb then its possible the float is stuck and not letting it get any gas at all

[macdude443]

To use the carb with stepper (aka Feedback Carter BBD) after an ECM test bypass, remove the stepper and set the needles like the photo below.  The stepper only has a limited control over the air/fuel ratio and cannot cut off fuel flow entirely.  My guess is a stuck needle valve or a float problem.  So you're aware, needles farther into the carb body=richer, needles pulled out into the stepper housing=leaner.

[Beaverseagle]

Thanks for the tips.  It turned out to be bad fuel lines and fuel vapor return lines near the gas tank.  I replaced them and she's running and pump gas like a champ.  She's got so much fuel pressure now my rust metal fuel lines now have leaks.  Order new lines!