JKU stalling at idle

    • JKU stalling at idle

      I have been chasing a power loss demon for a couple months. recently had my plugs changed out hoping it was that.The power loss seems to have gone away, but now I will randomly stall at idle.

      When the power loss happens the tach drops 500-1000 rpm and it "feels" like the trans is slipping.

      When it stalls its idling at 650(ish) and it will sputter for a second then drop to 0. No codes, and starts up afterwards. Whats really tripping me up is sometimes, after restarting, it wont go into gear. I just shut it down and then restart and the problems is gone.

      I looked last night and the air filter was gunked up pretty bad, so I was thinking maybe its a breathing issue. Cleaned that and started her up. It didnt stall, but it would still have the power loss of 500rpm or so.

      I also thought maybe bad gas. I ran a water treatment and a can of seafoam through the last tank and a half. It seemed to help, but i really dont know.

      Research is pointing me towards the vacuum lines, an o2 sensor, or cam phaser problems.

      Any one have any thoughts?
      2013 Jeep Wrangler 4 Door (JKU)*SOLD*
      2020 Jeep Gladiator JT
      DE tag : OIF 118
      Honk if you see me!

    • Does that have an IAC sensor (Idle Air Control) on the throttle body?

      Not sure how the newer EFI systems work. But one thing I found when mine would stumble at idle (OBDI system) was a fuel leak at the pressure relief valve on the fuel rail (not sure what the official name is). It's vacuum actuated and returns excess fuel back to the tank. While driving the engine is pulling less vacuum so the relief valve stays closed (engine needs all the fuel). When you come to a stop and return to idle the engine pulls more vacuum and opens that valve to return the excess fuel since the engine doesn't need it.
      :spinrhead: ...covfefe... :spinrhead:

      The post was edited 1 time, last by Slimer ().

    • it does have an iac and it would be good to clean or replace it. U may want to pull the tb to clean it and the sensors.

      The jk fuel system is similar to a tj and the regulator is mounted on the fuel sender so there is no vacuum operated regulator like on a yj.
      '88 YJ with not much '88 left. :)
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    • Turns out my throttle body and fuels injection points were almost occluded with gook...after dealer cleaned it the problem stopped.

      Sorta makes me loose faith in the seafoam cleanse.
      2013 Jeep Wrangler 4 Door (JKU)*SOLD*
      2020 Jeep Gladiator JT
      DE tag : OIF 118
      Honk if you see me!