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  • #1

    Having lean cold start idle problems

    For a long time I was struggling with the P0171& P0174 fuel trim lean codesand finally found out that the EGR pipe from the Valve to the intake was cracked.

    Well I replaced the pipe from the EGR to the intake, used the high temp copper sealant to seal it up good and also replaced the gasket for the EGR valve last night. The car seems to idle better but from a cold start the AFR reads around 14.7 at the initial start up but after about 30 seconds it starts to go lean and if I try to acclelrate at all the AFR readings max out on the wideband, the car will also buck a little when I do this. This will happen until the car warms up and then everything is fine with the AFR reading around 14.7.
    Any ideas what would cause this?
    2002 v6 camaro supercharged with a powerdyne pushing 12PSI, I also have an aluminum driveshaft, headers, high flow CAT, flowmaster exhaust, HP Tuners, AEM wideband, throttle body spacer, PCV bypass, cartech adjustable FMU, timing control module (wich I don't need now with HP Tuners but I am not going to spend the time to take it out), 3.23s with LSD, Spec stage 2 clutch, Exon (I think that is how you spell it) Ground effects, P&P throttle body, and GTP 36# injectors.
    Tags: adding, afr, art, con, control, decay, drive, fuel, general, hptuners, make, mine, minute, o2 sensor, open loop, problem, real, rich, run, star, start, start up, startup, tables, til, tuners, understand, ups, v6 camaro
  • #2
    have you tried adding fuel with hp tuners for start ups, make it a little richer?
    ------------------------------------------
    2004 GMC Envoy - Tuned, Airraid Intake, rest stock
    2005 Malibu - Stock, anyone have a ecotec factory gm supercharger for me? lol

    5th gen Camaro V6 Forums
    http://www.bowtiev6.com

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    • #3
      No I have not tried that yet, I am not sure how to adjust the fuel at start up. Do you just adjust the MAF table or is there another way?
      2002 v6 camaro supercharged with a powerdyne pushing 12PSI, I also have an aluminum driveshaft, headers, high flow CAT, flowmaster exhaust, HP Tuners, AEM wideband, throttle body spacer, PCV bypass, cartech adjustable FMU, timing control module (wich I don't need now with HP Tuners but I am not going to spend the time to take it out), 3.23s with LSD, Spec stage 2 clutch, Exon (I think that is how you spell it) Ground effects, P&P throttle body, and GTP 36# injectors.

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      • #4
        I'm having a similar problem and mine seems to run rich on warm startups until I drive it out for a minute or too, but I'm not real advanced in HPtuners but from what I understand the problem is in the tables.
        Doing less with more


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        • #5
          Originally posted by 2002 v6 camaro charged
          This will happen until the car warms up and then everything is fine with the AFR reading around 14.7.
          Any ideas what would cause this?
          Its your open loop tune. Until the O2 reaches operating temp it just runs off defined values. You probably just need to richen up the gms/sec MAF tables at those flow rates. (this is coming from an OBDI guy). Im not sure if its all the same for OBDII.

          Also you could switch out your O2 sensor for a 3 wire heated one. Or maybe your car came stock with a heated one? Dunno. Heated O2s help it into closed loop faster and help it get a decent reading at idle when its not getting much heat.

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          • #6
            Matt got it dead on.

            You need to get into the open loop tables and make them more appropriate for your car. The tables are based on a bone stock ride and even when you start modding a little bit they are off.

            The closed loop table is more forgiving but still could use improvement if you are untuned.

            Once I get my tuning suite I can get you hooked up, but until then I suggest you venture over to Wheel2Wheel and get properly tuned.

            SpeedDetroit Speedshop <Owner> Detroit's Only True Grassroots Speedshop
            http://gasfed.blogspot.com/
            Originally posted by KuruptWS6spd
            And yes my box is ALWAYS this clean

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            • #7
              look under:

              engine>fuel control>general fuel

              there are some decay tables and such to adjust afr at startups
              ------------------------------------------
              2004 GMC Envoy - Tuned, Airraid Intake, rest stock
              2005 Malibu - Stock, anyone have a ecotec factory gm supercharger for me? lol

              5th gen Camaro V6 Forums
              http://www.bowtiev6.com

              Comment

              • #8
                Cool, thanks for the help guys.
                2002 v6 camaro supercharged with a powerdyne pushing 12PSI, I also have an aluminum driveshaft, headers, high flow CAT, flowmaster exhaust, HP Tuners, AEM wideband, throttle body spacer, PCV bypass, cartech adjustable FMU, timing control module (wich I don't need now with HP Tuners but I am not going to spend the time to take it out), 3.23s with LSD, Spec stage 2 clutch, Exon (I think that is how you spell it) Ground effects, P&P throttle body, and GTP 36# injectors.

                Comment

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