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Thread: 2006 Wrangler 4.0 SC 2 bar srt8 6.1 inj. Engine shuts off in boost, no open loop

  1. #1
    Tuner in Training
    Join Date
    May 2020
    Posts
    29

    2006 Wrangler 4.0 SC 2 bar srt8 6.1 inj. Engine shuts off in boost, no open loop

    Hey guys. I'm doing my first 4.0 jeep with forced induction. I believe I have all of the initial stuff to the tune done properly. The jeep runs darn perfect when not in boost.
    It has 6.1 srt8 yellow band injectors, a 2 bar srt4 map, and a PD blower that makes 10-12 ish PSI.
    The problem I am having is the engine just shuts off in boost. Once you pass about 1.15-1.2 pressure ratio its like someone shut the key off. The key gets cycled and it starts just fine and runs fine. I have not been able to figure out why yet and am looking for some help.
    I have included my tune and a log of it happening. In the log it happens between the 30 and 31 second mark.
    Also does my baro adjustments look correct? I still get a baro code. I'm not sure if I missed somethingSC3 pnw.hptShuts off 30-31 seconds.hpl

    Also, what sets closed loop/accel enrichment/PE mode in these things? I can not seem to get the PE to come in no matter what I do. I can make full boost in this thing and never get PE regardless it seems what I do with the "wot pedal threshold" setting in the "fuel" "power enrichment" tab. I log throttle and I'd like to see my PE come in around 1/4 throttle or so as thats when the PD blower starts to make significant boost.
    Thanks for any and all help.
    Last edited by vr4508; 10-27-2021 at 06:06 PM.

  2. #2
    Advanced Tuner
    Join Date
    Apr 2014
    Posts
    704
    With the way you're trying to run this thing (power enrichment so early in the pedal), you'd probably be better off turning off o2 sensor feedback, and run in open loop without using the power enrichment fuel adder table. You would just tune your VE table to add the extra fuel for any pressure ratio at and/or above atmospheric pressure.

    As for your jeep shutting off, it's hard to say what might be causing that. I see your injector pulse and ignition timing drop way off, effectively killing the motor. It makes me wonder if there's a protection mode beyond the typical limp mode that's shutting things down. One of the things that comes to mind is that you're getting a great deal more airflow at part throttle than what the engine diagnostics model was originally calibrated for. Might be worth maxing out ECM 3922 (Airflow Max TPS, under Engine Diag General) to see if that has any effect.