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Thread: 454 TBI problems!

  1. #1
    Carb and Points!
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    Unhappy 454 TBI problems!

    I have a 1993 k3500 454 NV4500... The engine is a semi fresh rebuild(50K miles) with a small cam. I have replaced the following some parts multiple times... The truck has a stumbling rough idle. Seems to lack power to me but im not sure. If i take the truck for a short drive when i come back and go to instantly restart it has no fire from injectors....hit it with a little ether and shes up and running again. Im fairly positive i have that narrowed down to a weak oil pressure sensor.(changing it tomorrow). The truck runs pig rich and never seems to go into Open loop.(i think heated 02 will change that). I AM OPEN TO ALL SUGGESTIONS.. out of ideas myself.

    I have a ALDL cable with WinALDL & Tuner pro rt but quite frankly do not know what i am looking for I have attached a copy of my logs at a idle.
    https://docs.google.com/spreadsheets...#gid=361545408

    Parts replaced less than 300 miles ago.( All new with AC Delco parts)

    Completely Rebuilt TBI unit with 2 inch spacer

    New TPS & IAC i did my best to calibrate them

    New map sensor

    Pickup Coil ( Timed at 4 degrees BTDC with connector unplugged)

    Cap rotor & Plugs & Wires

    ICM

    Ignition coil

    o2 sensor ( Re wired from ecu wire was broke assuming when they reinstalled the engine)
    *** I plan on switching to a heated o2 due to my long tubes.

    CTS

    Knock sensor (Wire was also broken)

    Newer fuel pump & Filter 15k ago with all new lines

    Im sure there is plenty others im forgetting. The EGR is deleted as are all other vac lines except MAP,PCV. I am at my wits edge with this truck but i love it very dearly. Hopefully the geniuses on here can help me figure it out. At this point any direction is better than none.

    Thank you very much you can email me at lvoithoffer@yahoo.com Or text me at 724-570-8672 if that is easier.

    Lucas

    Picture of said truck causing me all this heartache

    48239690_10211123930408340_4511094938007502848_n.jpg
    Last edited by Lvoihotffer; 04-07-2019 at 08:00 AM.

  2. #2
    Super Moderator dave w's Avatar
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    What is the computer number and chip code you are working with?

    dave w

  3. #3
    Carb and Points!
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    Quote Originally Posted by dave w View Post
    What is the computer number and chip code you are working with?

    dave w
    ECU # is -1227747

    How would i go about finding out the chip number? It is a Factory chip as far as i know...

    thanks, Lucas

  4. #4
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    The chip number, or BCC, is located on a label on the chip. Remove the ecm, open up the cover, and you will see a larger and a smaller chip. The larger one is the one to check. Try not to touch the chip itself unless you are properly grounded. They are sensitive to static shock.

  5. #5
    Super Moderator dave w's Avatar
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    Link to 1227747 information: http://www.gearhead-efi.com/Fuel-Inj...Information-42

    The link above has the files required to use TunerPro RT.

    Perhaps searching YouTube video's on "How To" TunerPro RT will be helpful?

    I use TunerPro RT to troubleshoot. See pictures below for 1227747 Sample Troubleshooting information.

    I consider WinALDL OBSOLETE!

    dave w
    Attached Images Attached Images

  6. #6
    Carb and Points!
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    Thank you for the fast reply! I solved the issue mainly today...was me deleting the EGR valve for no reason i guess it being a 1 ton the egr is a ported valve and plays a big roll in the engine running correctly.....Anywho now that the spending spree is over for now i found i have the 1228747 ecm which i do not fully understand being my truck is a 93...Am i correct that this ecm doesn't use a knock sensor? I originally didn't have a plug for it i assumed the po ripped it off pulling the engine. I found the wire in harness and re did it and it made the truck run horrible. i have it unplugged now and is much better. Only issues now are popping out of exhaust mainly on decel sometimes idle. Timing is dead on but it also is probably a 195k miles dist. possible valve adjustment? the truck has a hesitation is seems part throttle cursing. bad tps maybe? on wot the truck pulls hard and smooth no popping from exhaust.... Mainly if i go out for a drive and return and shut the truck down and try to restart it just cranks no fire from injectors. dump some gas in the tbi and off shes running all the problems seem to only happen in open loop with the 02 controlling fuel. I am going to get familiar with tuner pro rt tonight. As for now if you could take a look at this log and let me know what u think i have made it into a nice spreadsheet for easier viewing. From what i understand its running fairly rich also noticed it shows no MPH input but my speedo does work. Im sorry for the long winded post but on here is the only guys that help point you in the right direction.

    https://docs.google.com/spreadsheets...gid=1721813780

    Thanks Again,
    Lucas


  7. #7
    Super Moderator dave w's Avatar
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  8. #8
    Carb and Points!
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    Thank you. Just got tuner pro figured out.

    Lucas

  9. #9
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    Quote Originally Posted by dave w View Post
    Care to take a look at these? truck seems to go rich lean and load up at steady throttle. wot runs decent.

    Thank you,
    Lucas
    Attached Files Attached Files

  10. #10
    Super Moderator dave w's Avatar
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    See attached,

    dave w
    Attached Images Attached Images

  11. #11
    Electronic Ignition!
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    Any progress, Lvoihotffer? I’m curious to see how you’re coming along. I’ve been struggling with a ‘93 7.4L swap for months now. The injectors not firing ended up being the distributor in my case. Probably the magnet because I had already replaced ICM, ECM, dist. pick up coil, cap rotor wires, IAC and pretty much everything else I could think of. When I replaced the ECM I went with the 7747 so I could hook up the knock sensor.

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