Recent content by JimR

  1. JimR

    speed density mode questions

    A mainscale of 0 simply means no adjustment. It always starts out like that. The nice thing about this change is that you don't have to guess or depend on other people's numbers. You simply do the math yourself and get the exact number you require. 0-(440/870)=-0.50 and -0.50*100=-50% After...
  2. JimR

    speed density mode questions

    It will not be able to auto-adjust enough. If you want to run 14.7, I suggest you turn off all Part Throttle Tracking and let the 7M ECU do it's job. It is very good, and very stubborn and persistent about maintaining that ratio, lol. :-) You must have a narrowband O2 sensor still installed for...
  3. JimR

    Vf tuning question (Maft Pro)

    If you guys are going that route (simulating), then make sure you're either using a pre '89 stock ECU, or make sure you deal with the Heater Circuit check. The later ECU's check for the presence of that heater circuit, and if they don't find it they may throw code #21, and drop into limp mode.
  4. JimR

    Vf tuning question (Maft Pro)

    Aaahhhh, there is another good possibility. Get rid of all accessory electrical loads while you're checking the idle AFR's, including mini cigarette-lighter power supplies, AC, etc. Let the car "settle in" as well, giving it time to adjust. Then start adjusting values using the maftpro keypad...
  5. JimR

    Vf tuning question (Maft Pro)

    Something doesn't quite add up though..... you're getting slightly richer afr's than normal at idle, yet the ecu is trying to add fuel.... hmmmm. Somewhat unrelated.... but have you pulled 20% from your mainscale to account for the 550's? Assuming you're using VE Table 2. Boost leaks are...
  6. JimR

    Vf tuning question (Maft Pro)

    Are you getting the flop-flop-flop on the diag port from the stock 02? (As per these instructions: http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=119 ) 4.43 volts means your stock ecu thinks the engine is running lean, and it's adding a lot of fuel (~10% to 20%) to even...
  7. JimR

    Vf tuning question (Maft Pro)

    What is the current setup of your original stock 02 sensor? Do you have any codes? Is your fuel pressure setting intentionally low? 33psi is at the bottom of the scale for stock pressure.... just something to check if you haven't already been down this road...
  8. JimR

    MAFT Pro into 2JZGE-T on 7M electronics with LC1 - New issues (shocking I know)

    Good to hear :-) The stock ECU is a smart unit and it will fight hard to keep control over idling, cruse, and all low load conditions. The best combination seems to be to let it do it's thing with a solid narrowband input, and focus your tuning on the top end when it goes into open loop...
  9. JimR

    MAFT Pro into 2JZGE-T on 7M electronics with LC1 - New issues (shocking I know)

    The first thing I would recommend is to pull out the multimeter and check what the LC1 is actually outputting for voltages (over time, and with the engine running) on the outputs. That will tell you if it's operating correctly, and if it is still set to defaults. Secondly, refer to your...
  10. JimR

    Help with Maft Pro

    That zipfile contains a link to the file, not the file itself... ;-)
  11. JimR

    Help with Maft Pro

    The first thing to note here is that since you are running speed density, vacuum leaks no longer matter. So you can definitely stop worrying about that one. ;-) Here is how I would go about this.... most of this centres around getting rid of possible variables and simplifying: 1. Turn off /...
  12. JimR

    ahhhhh is full throttle down????

    The site's working fine now (at least for me!) Have a read here: http://fullthrottletech.com/showthread.php?t=6386
  13. JimR

    As Requested: MaftPro Install writeup

    You need a set voltage for the HAC sensor input. The voltage divider circuit is what lets you accomplish that. Take the numbers from the diagram, put them into the formula, and you will see the resulting voltage (~3.4v). The HAC wire goes off to your HAC input on your ECU (89+) or to your...
  14. JimR

    Maft Pro capabilities

    Those numbers are at the upper limit of any piggyback system. Assuming 780cc injectors or larger, your 'corrected' airflow number to the ECU will be about half of what's really going in. This will cause the ECU to advance the timing a little too much for a given load, and you'll need to wire up...
  15. JimR

    MAFTpro tune problems

    First, as far as I know, open loop happens after 70% TPS, regardless of rpm. Second, open loop also happens after 3500rpm with a certain, lesser amount of TPS... I'm not sure how much. The likelihood of Fuel cut will increase as the RPM's rise, due to the increase in air consumed. Your 60-1 is...