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Thread: 6.0 goes dead lean in boost. Log and file attached.

  1. #21
    Tuner in Training
    Join Date
    May 2020
    Posts
    26
    According to the website I got the sensor from, it calls for 305 and 10.33. The scanner also shows 105 kpa and the vac/boost gauge lines up with what the ecu is showing so I think the sensor values are pretty close. I have tried a few different sensors, all with the same results.

    I attached a new pair of logs and a tune that is in the truck now that I'm trying. Still exact same problem. The difference between the two logs is 20% richer in boost with the RTT table. You can see the diference in the duty cycle and pw between the two.

    Not really sure what to do next.
    Again, with a microsquirt and all the exact same sensors, pumps, injectors ect, the engine runs fine. Pulls to gate and only stops when I do. I have not spent a bunch of time tuning it this way as I want to use the factory ecu, but it responds and works as it should.
    Anyone else have any ideas at all? This thing should be heaving black smoke in boost by the looks of the ve table, and instead it pegs the WB and lean pops back through the intake.
    Is there some max kpa clip I'm missing? Or? Its seems like at some point it kills the PW but the log does not show anything I can see.
    Attached Files Attached Files
    Last edited by vr4508; 05-08-2021 at 04:04 PM.

  2. #22
    Tuner in Training
    Join Date
    May 2020
    Posts
    26
    So, I'm still fighting this thing. I have tried a number of things to try and fix it.
    As the problem only comes up when the truck starts to roll into boost, I figured it may be caused by some map based enrichment/enleanment. Also as the truck runs fine with a standalone ecu running super similar PW's I thought is may be an issue with the boost PE table.
    So things I have tried lately,
    I tried a completely different ecu. Started over from scratch with a 3 bar sd file and ran into the same problem, truck runs great everywhere else but as soon as it makes boost over about 110kpa it goes dead lean, pops through the intake, peggs the wideband lean and falls on its face. It recovers instantly though and runs fine.
    I have run another fuel flow test and it the fuel system flows way more then needed at this power level.
    I Thought it could be caused by a particular PW or DC on the injectors, so I have tried changing the injectors. I have run de-caps, deka 60's, deka80's and bosch 210's. All with the exact same result. The 210's are in the truck currently.
    I tried turning off boost enrichment and just running iot off of the open loop PE table, no change.
    I also thought it was possible that the issue may be caused by hitting some calculated value I can't see or don't know about. So on a hail mary I scaled the injectors, cylinder volume ect by 50%. This changed my cyl airmass a bunch but did not change the symptom at all. Still goes instantly lean in boost.
    I have tried 3 different "drop in" 3 bar map sensors for the tbss intake, no change. I tried a old 3 bar brick map t'd into the intake manifold, no change, and I have run a factory zr1 map also t'd into the manifold, also no change. (for each sensor I changed the map sensor values to give an accurate reading)
    About the only thing I have not tried swapping is the harness itself, I'm just not sure how a harness would be able to cause this issue.
    I am tempted to try to run the factory ecu tune, fail the maf, run it open loop with a 2 bar sensor and just see if the issue crops up still while running on the top half of the ve table at what would show as about 65=70 kpa when it was making 3 ish PSI. I know it sounds hackey but at this point...........

    Does anyone know what all inputs are needed in the factory ecu to control the trans?
    If its doable I'm at the point of just letting the factory ecu shift this thing and run all the body control, gauges, cruise ect stuff and I'll wire a microsquirt to control the engine.
    Last edited by vr4508; 05-13-2021 at 11:42 AM.

  3. #23
    Tuner in Training
    Join Date
    May 2020
    Posts
    26
    I fought this thing for over 6 months with no solution and no light at the end of the tunnel.
    So I kinda threw in the towel.
    I tried everything I could figure out to do and never got anywhere, so instead of continuing to beat my head into the wall, I wired a microsquirt up parallel to the factory ecu. I split the crank signal, left the cam plugged in for the factory ecu, split tps and map, stole the injectors and ignition outputs along with iac for the micro, stole the iat sensor for the micro and added another ect for it as well in the opposite cylinder head. This worked out pretty slick really. The factory harness and fuse box still supplies all the power and the factory ecu shifts the trans and runs the a/c and the rest of the truck perfectly. All the wireing was done right at the blue/red connctors so the install is nice and clean. Just a factory harness with a 30" micro pig tale the breaks out of the factory harness right at the ecu. I can also still use the scanner to watch for knk which is kinda cool as the micro has no provisions for knk sensors
    It took about 2 hours of wiring and the truck fired and ran right off the bat. I put it back on the dyno and at 18 psi broke 700 rwhp. Since then it has about 3k miles on with no issues. cruise works, all the gauges work ect.
    On one hand I'm a bit bummed that I was not able to ever get the factory ecu and HP to work properly on this truck but on the other I have a reliable fun 700 hp truck to drive every day. The only kind of annoying thing is needing to use HP to flash the factory ecu every time I want to change the shift points or feel. That said I haven't messed with them in weeks so its kind of a non issue. The trans shifts great and the engine finally is happy.
    I know HP works great and I'm willing to admit I was not able to figure out why this acted the way it did, and I have tuned a few very similar truck since fighting this on with HP and they are all great, but for some reason, on this truck, it just never worked properly. So this was my fix. Might not be ideal, but its kept the pistons in this thing.
    So thanks for any and input and advice you guys sent my way.
    Last edited by vr4508; 07-07-2021 at 01:18 PM.