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Breaking up at around 4k

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  • Breaking up at around 4k

    It's been a while since I posted here. I am having an issue where at around 4k the car falls on its face. Does this sound like a fuel regulator problem. It has a 400lph walbro and frpp 60lb/hr. The two items listed are only a month old.

  • #2
    Are you able to datalog fuel pressure, fuel pump duty cycle, injector pulsewidth? How about the MAF, is it pegging? Is the car boosted? Maybe its spark blow out.

    You should post the details of the vehicle and possibly logs and tune files to have others help. Otherwise you will either get no responses, or a bunch of speculation based on the vagueness of the description.


    • #3
      mtWOT8apr16.csv this was held in a little long. The car has a walbro 400 lph pump, 60lb/hr injectors and a ba5000.


      • #4
        The car is running 14 psi via a 70mm turbo.


        • #5
          Check to see if your manifold volume in liters is set at a stock number, or very close to it. Too high a manifold volume in liters will cause the engine to go lean very quickly with the motor nosing over. This issue can also be affected by the engine displacement being way far off of stock number. Ideally, the idle load should be about .150 to maybe .225. One last possibility is to look a the Ynorm scale of the borderline spark table. The Borderline Spark table has a scale on the left side. The lowest number may likely be .100 If by chance the lowest number on the left side is up around .200 or higher, there may be a need to adjust the Ynorm scale to lower the bottom number to .100. A great way to figure out the lowest number for the Ynorm scale is to data log a drive on the street at about 40+ mph, shift down into second, and take the foot off the gas pedal. Allow the data log to continue until the car almost comes to a stop. This deceleration technique will drive engine loads very low, often below loads of .100. My lowest Ynorm load is 0.080. If the lowest Ynorm number is set too high, the PCM does not know how to respond very well when the engine loads are below the lowest number on the load scale. One other point, if the LWFM table is stock, that will not help your nosing over problem with a turbo setup.

          Of course, the above info may not relate to your car as you did not post any info about it, such as engine size, model year, or type of vehicle.
          Last edited by 6 Shooter; 04-14-2016, 08:25 AM.
          '00 V-6 Mustang auto vert, 4.3L stroker, 9:1 CR, Crower billet crank and rods, 600 lift cam, 4-bolt main caps, 8mm valve stems, dual LS springs, ported heads, twin Garrett 3071s turbos, meth injection, twin GT Supercar pumps, Cobra tank, HPX slot MAF, 80mm throttle body, '04 KWZ2 PCM, custom upper and Freestar lower intakes, custom fuel lines & rails, ID-98 injectors, Dash-DAQ data logger, LMA-3 for RPM and boost


          • #6
            I myself am not tuning it. Mr Don lasota is, having an issue where the fuel ratio goes lean around 4k. He said that it is a mechanical issue and I'm trying to find it. Btw it's a 2010 mustang gt


            • #7
              datalogfp.csvthis is when I data logged the fuel pump and rail pressure. it drops off when I get around the 4k rpm. ​