Results 1 to 11 of 11

Thread: Dead Fuel Trims, Non switching 02 sensors and stuck on 9mv..

  1. #1
    Tuner in Training
    Join Date
    Jan 2019
    Posts
    13

    Dead Fuel Trims, Non switching 02 sensors and stuck on 9mv..

    Hi guys, im very new to Tuning, i do know basics.
    The car is a 2007 MK2 FPV GT Supercharged..
    Had it on a Dyno 8 months ago, and drove well for a while and from time to time it would idle and cruise badly, but it would eventually clear up..
    Power pulls were no problem.. 2 month ago i fitted a wide band gauge and all was well.. AFR was 14.7 and low 12s on pulls..
    Then the next day the engine was rocking on idle again and the AFR was 9.5 for a moment then sitting on 10.5 but on pulls no problem.. 12.2
    It would come good most of the time within 30 mins to 14.7..
    A week later it happens again then eventually all is good again and so on.
    Then last week it was permament with 11.3 on idle and cruising, no ploblem on power pulls at 12.3 ...
    I decided to purchase the MPVI2 hardware and found the fuel trims not active.. 02 sitting on 9mv ..
    I removed the battery leads for 5 mins and reconnect the battery, started the car and AFRs are perfect.. The fuel trims are active and the 02 sensors switching between 4.5mv..
    Short Fuel Trims running close to zero but Long Fuel Trims sitting on -25% ?? Seemed like compensation ? But the car was running well..
    Drove the car with no problems.. Tonight i thought id setup the Bluetooth to my Laptop and paired up nicely..
    Opened up the VCM Scanner and noticed the Trims displayed Not Ready? Started the car and 02s not switching and short trims trying to work while the long trims were at zero, then faulted and the AFRs dropped to 10.1
    Turn key off then on, engine off and Trims are Not Ready, short trims are on 25% ..long trims at zero.. 02 sensors roughly .003v
    If i start the engine the 02s are dead, trims goes to Fault..
    If i disconnect the battery hence rebooting the ECU, it will post and run perfectly.. ?? Well for a little while..
    I surppose i get learn more about this software!
    Any ideas from you professionals would be appreciated!
    Cheers ..Kevin

  2. #2
    Advanced Tuner
    Join Date
    Jul 2018
    Location
    Texas
    Posts
    214
    Post a tune and a log. We need to see what's going on. The vehicle has to warm up from cold start before normally operating 02's are active and vehicle goes to closed loop. It may be running perfectly until warm up b/c computer controls engine operation until 02's warm up and take over. Scan the vehicle for codes with the software under VCM Scanner. Make sure you have 02's in the channels to log their operation and the 02 status i.e. CL or not. Also injector pulse . -25% is rich and computer is trying to remove fuel by cutting injector pulse.

  3. #3
    Tuner in Training
    Join Date
    Jan 2019
    Posts
    13
    Thanks DGS..
    When its cold the wide band is good, as soon as it warms up the Fuel trims fault, and the wide band shoots down to 10.1
    Ive found how to send a video and photo, but having trouble sending a file..
    Ive also have to setup up the Injector Pulse layout in the scanner..
    Ive just got Hp Tuners 3 days ago, so im very green with this software.. Seems very impressive though..

  4. #4
    Tuner in Training
    Join Date
    Jan 2019
    Posts
    13

    Fuel Trims

    GT.hplGt SuperCharged Original Map.hpt

    Hi DGS
    Ive attached the log and map file..
    I started the car and let it warm up, as you can see the Short Fuel Trims are very busy and then faults ..
    The 02s arent switching?
    I did relize that the -25% Long Fuel Trims was leaning the fuel but didnt know why..

  5. #5
    Advanced Tuner
    Join Date
    Jul 2018
    Location
    Texas
    Posts
    214
    If you watch the log you will see the Fuel System Status #1 go to CL - closed loop. This is the point where the 02's heat up enough and are active/switching. Once this happens you can see the 02 (short term) are 0.900 which is reading too much fuel. (In a properly running engine, the 02's switch from high to low voltage and the ultimate goal is an average of 450 which would be 14.7:1.) Then you see the short term fuel trims at -20%. The computer is removing fuel b/c the 02's are reporting back to the computer it is too rich. when the % values get too far out the system then shows fault. I'm guessing you are setting a code. Do you have a check engine light on? That will probably tell you what's going on. If the 02's aren't active/ switching the computer just commands fuel based off of a table value that keeps it at 14.7:1 and does not utilize the 02 sensors.

  6. #6
    Advanced Tuner
    Join Date
    Jul 2018
    Location
    Texas
    Posts
    214
    Many of the sensors are set to no MIL light in Engine Diagnostics in the tune. You will not know you have failures. The exhaust manifold protection is turned off as well as catalyst protection and component protection in the tune. Did you modify your tune or was it this way when you started? When you stated dyno, I assume someone modified your tune? Appears after dyno tuning, parts of the tune were not turned back on. If you modified your tune, I would go back to your factory tune and start over. Find out how it runs on the factory tune. Hopefully you copied and saved it. If you don't have a factory tune, you can possibly find one in the repository or somewhere listed in one of the posts that you can compare yours too and get it back as close to factory as you can. I don't work on Ford's , so I don't know what some of these factory settings are. I would have to compare myself with a known good factory tune and make those changes. If you did make changes, you need to decide what you are trying to accomplish and then just modify one thing at a time and check the results. Key on will not give accurate 02 readings and should not ever show ready. The engine has to be running and go to closed loop - CL. You risk damaging the cats if they aren't damaged already. I would not continue to drive set up this way. No telling what else you may damage engine wise.
    Last edited by DGS; 01-27-2019 at 02:54 PM.

  7. #7
    Tuner in Training
    Join Date
    Jan 2019
    Posts
    13
    Thank
    I havent changed the Tune since picking up the car from the Tuners.. Just for interest..The car made 380rwkw and 850nm with a standard engine except for air filter and larger exhaust..Diff is the standard 2.73 ratio..
    I havent got the original map, the Tuner may have it..?
    I cant use the original map because ive fitting a Whipple Supercharger to the car, which now runs a 2 bar Map Sensor replacing the single bar Sensor.
    I had the car towed to the tuners to have it tuned for a Supercharger, the tuner had dramas with it and i had to take it back 8 times..
    The main problem was the map sensor that was supplied with the Supercharger kit wasnt compatible with the Ford ECU.. The Tuner replaced the Map Sensor
    with a Ford OEM 6 cyclinder Turbo Map Sensor, since then it was a driveable car, but there were a few bugs with the car and didnt want to take it back again.
    I fitted the wide band gauge and noticed the problems i was having.. I figured the tuner turned off the engine warning light, especially when the long term trims were at -25%..Like you said, the ECU is taking fuel..
    Hence buying HP Tuner Pro..
    I disconnected the battery for 2 hours and it didnt wake up the 02s, they went to .9 and the trims went to fault!
    I decided to hold the rpms to 2000 and for some reason the 02s woke up and seems to be running well .. Long fuel trims are still -25%.
    I went for a long drive and she went well.. I did Log the drive, so ill keep going over the log as i learn more about this software.
    The Ford FPV Gt isnt a common car and not many fitted with Superchargers, so comparing tunes is very rare.

  8. #8
    Tuner in Training
    Join Date
    Jul 2017
    Posts
    22
    Hey Bolly

    I have a stock tune for a 2007 BF FPV (that is what it was named anyway) that I think I jagged from the repository before it went to shit. I don't know if it is the same as what yours would be prior to the blower but let me know if you want it mate. Might be useful for a comparison.

  9. #9
    Tuner in Training
    Join Date
    Jan 2019
    Posts
    13
    That would be very helpful.. Cheers..

  10. #10
    Tuner in Training
    Join Date
    Jul 2017
    Posts
    22
    No worries mate, hope it helps.
    Attached Files Attached Files

  11. #11
    Tuner in Training
    Join Date
    Jan 2019
    Posts
    13
    Many Thanks..