Bringing TBI and Multi Port Fuel Injection to a New Level.     EFI Conversions and Tuning! Seattle to Portland! E-mail Tuning Consultant!
Page 1 of 2 12 LastLast
Results 1 to 15 of 21

Thread: 94 F-body LT1 solving problems/tune

  1. #1
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35

    Cool 94 F-body LT1 solving problems/tune

    Hi everybody
    I own 94 TA LT1 4l60e and 2.72 gears
    It is stock with some mods for now
    -rebuild tranny with corvette oil pump, z-pack and rougher/faster shifting
    -trans oil cooler
    -engine oil cooler
    - 94 vented opti
    -k&n air filter
    -cat delete
    -TB coolant bypass
    -intake elbow silencer delete
    -oil temp / fuel press / vacuum - gages
    -fan switch

    I want to tune it.
    Let's get started

    Factory bin file attached
    Attached Files Attached Files
    Last edited by yoheer; 05-02-2020 at 10:27 AM.

  2. #2
    Fuel Injected!
    Join Date
    Jul 2019
    Location
    Orange, CA
    Posts
    296
    You should probably start by stating what problems you’re actually having so that they can be addressed before wasting time tuning.
    1994 Corvette (Automatic)
    1995 Corvette (Manual)

  3. #3
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    Well
    I was cruising and got a SES light with code 44. Left bank lean condition. I had it earlier but i found a problem with HVAC vacuum leak. I fixed it, cleared the DTC.
    Today after all I checked the engine for leakes with smoke machine and found one in optispark. I moded 94 non-vented opti to vented earlier as you can see above. I converted it back to non-vented and checked everything again. No leaks. Done.
    But I watch throug the Eehack logs and I dont know if theese are normal parameters: (there is no much differences before and after vacuum fix in logs BTW )
    MAF is 7.5 g/s at idle
    IAC position sometimes 6 to 9 at idle
    BLM is on
    Also maybe smth is wrong
    Here are logs
    Attached Files Attached Files

  4. #4
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    So, can anybody take a look? Or I need some logs from good working stock car. I will compare.

  5. #5
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    3,220
    i haven't looked at your logs, but with the maf and iac so low you probably have another vacuum leak or unmetered air somewhere. the maf isn't reading much airflow, but the IAC is trying to lower your RPM. it's a very old car so anything rubber or plastic is suspect but also things like your 'intake elbow silencer delete' need to be rechecked.

  6. #6
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    New logs. I drove a car all day on my business.
    What I found
    Sometimes LBLM and RBLM drops less than 110
    AVGBLM too
    Generally on deacceleration but not always
    Checked, for vacuum leaks again. I have no leaks. I'm using smoke machine and I believe i would see if smoke came from somewhere.
    The only thing I havent checked is brake booster. I'll check it later, but brakes seems to be okay.
    I can attach those logs if needed

  7. #7
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    3,220
    i know from experience that if your brake booster leaks on an fbody, your brakes barely work at all.. but definitely do check it.

  8. #8
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    Most likely the booster will be ok.

  9. #9
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    Idle is 900-1200
    replaced the iac with used one
    then it rised to 2000
    used scan 94 95 to reset iac position
    after clicking on that button about 5 or more times it has dropped to normal idle and IAC was about 10-14 steps
    after restarting the car rpm is about 750-800
    but target rpm is 650
    IAC is about 20-25


    Faulty IAC?
    Attached Images Attached Images
    Last edited by yoheer; 2 Weeks Ago at 10:08 PM.

  10. #10
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    3,220
    your TPS is at 1%.... why is your TPS at 1%? it wont try to attain your idle target if the TPS is open.

  11. #11
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    Good question. I'll try eehach to measure tps. Scan 94 95 always shows 1%
    One more moment. The only leak i have is on the pic below. And I can do nothing with it. TB shaft.
    Attached Images Attached Images

  12. #12
    Fuel Injected! steveo's Avatar
    Join Date
    Aug 2013
    Posts
    3,220
    its normal for it to leak a bit there. it looks like you haven't adjusted your idle screw. make sure your throttle plates are closed as much as possible (just not so much that they jam in the bore). after doing all this, pull your PCM BAT fuse for a bit just to make sure ecm memory is clear.

  13. #13
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    Now tps is 0. Strange. I did nothing about adjusting that screw. Rmp just raised and thats it. 700. Then 800 in a week. Then 900 and so on

    Idle iac is 40 steps. Is it okay?
    Idle is 850.

    I'll try to install new tps. I dont like how it operates
    Last edited by yoheer; 2 Weeks Ago at 12:28 PM.

  14. #14
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    Faulty tps.
    Fixed.

  15. #15
    Fuel Injected!
    Join Date
    Apr 2020
    Location
    Belarus
    Age
    32
    Posts
    35
    Today was a next step with my pontiac
    I made mods with ECM.
    Installed EEPROM sockets for both sides. I want to say that there is no need in installing credit card pices. And no need to cut the bottom in a socket.
    All you need is heated table and heatgun.
    If you dont have a heated table you just can use household iron and a paper towel as a spacer.
    Everything works perfect.

    then I made some "cosmetic" mods:
    1. Cat potection disable. I have cat delete.
    2. Lowered the overheat enrichment protection
    3. Lowered BLM Hysteresis for more accurate idle
    4. AC clutch disable within lower TPS

    5. Disabled AIR PUMP - DOESNT WORK!!! AIR pump still engages on start. And I see in logs. How to finally disable it?

    6.Lower TEMP fans kicking.
    7.Lowered IDLE to 500. Works perfect.

Similar Threads

  1. OEM Tune - 97 LT1 f Body
    By OhNoItsGodzilla in forum OBDII Tuning
    Replies: 1
    Last Post: 09-17-2019, 05:45 AM
  2. Replies: 72
    Last Post: 11-26-2018, 07:14 PM
  3. 95 F-body Fuel Pump with 95 B-Body Engine/Tank
    By EPS3 in forum GM EFI Systems
    Replies: 7
    Last Post: 09-19-2016, 02:40 PM
  4. Need help solving surging deceleration and idle
    By Chewy1576 in forum GM EFI Systems
    Replies: 25
    Last Post: 02-21-2016, 03:17 AM
  5. Problems getting my tune down.
    By jay7199 in forum GM EFI Systems
    Replies: 7
    Last Post: 07-13-2014, 05:10 PM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •