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Thread: new guy with a cammed tbi that wont run right!

  1. #1
    Carb and Points!
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    new guy with a cammed tbi that wont run right!

    Hey tbi gurus...my dad converted his 86 c10 from carb to tbi using all the stuff from like a 90s van. He also swapped from a th350 trans to a 4L60e.

    The engine has swirl port heads, a large cam (enough to make it lope good-have to get the numbers on it later this evening) and is bored .030. Stock converter.

    Hes concerned about mileage...he thought that with the overdrive and tbi he would get much better but he isnt...hes getting about the same mileage as with the carb and 3 speed.

    He is using the stock computer...does it need tuning to make it run better? Any help is appreciated. Hes pissed that its not doing any better lol

  2. #2
    RIP EagleMark's Avatar
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    Even a stock engine can see some gains with some tuning done to the chip. With a cam change it's a must. If it has a lope at idle? I'm surprised he's happy with how it runs at all?

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
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  3. #3
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    Quote Originally Posted by EagleMark View Post


    Even a stock engine can see some gains with some tuning done to the chip. With a cam change it's a must. If it has a lope at idle? I'm surprised he's happy with how it runs at all?
    Yes has a big lope at idle. I knew it needed tuning! Who can do this for us?

  4. #4
    RIP EagleMark's Avatar
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    I can if you don't tune and burn chips.

    Need some more info like PCM number and chip BCC (four letter code) is the chip and PCM same one that came with the transmission? 94 to 95 4l60E transmissions are different and need to match the chip.

    Also cam specs and anything else done to motor. Headers?

    EGR hooked up? Air pump? CCP?

    Have you checked for error codes yet? What are they?

    Timing set to 0 with bypass wire disconnected?

    What is fuel pressure?

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  5. #5
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    Alright the trans and computer match...where can I find those numbers? Headers, no air pump no egr I think.....ill get the cam specs tonight for sure. Would we have to send you the computer to have it tuned?

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    Should be on the sticker on PCM. If it's gone you can open the plate with 2 screws and see a blue Memcal, pull it out and look for the four letters on a silver sticker.

    No i don't need the PCM, I'll send a memcal adapter with a new chip to plug into what you have. Like this:
    http://www.gearhead-efi.com/Fuel-Inj...er-form-Moates

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
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  7. #7
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    Quote Originally Posted by EagleMark View Post
    Should be on the sticker on PCM. If it's gone you can open the plate with 2 screws and see a blue Memcal, pull it out and look for the four letters on a silver sticker.

    No i don't need the PCM, I'll send a memcal adapter with a new chip to plug into what you have. Like this:
    http://www.gearhead-efi.com/Fuel-Inj...er-form-Moates
    Ok ill get that info. Whats the going price?

  8. #8
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    Ok. Truck has headers and egr is connected.

    He has had three codes. MAP sensor, egr, and spark knock.

    Here is the specs for the cam


    And here is the sticker on the pcm...let me know if anything else


  9. #9
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    Reman ECM does not tell what chip/memcal is in it. Have to pull the cover and memcal to read the four letters on it. Should be able to see them through hole in blue cover. If not pop the blue cover off. I probably have it but it should match the transmission.

    Clear codes by disconnecting power to ECM. Then see if they come back and exactly what numbers. MAP may be low vacuum do to cam, EGR and spark knock should not be there and they will have to be fixed, probably a wiring issue. EGR code could be from wrong EGR valve, there are 2 and look identical but do not work the same and cause error codes.

    That cam is rated fro 1500 RPM up to 5500 RPM. First the low end with a stock torque converter is going to have a little bog/dead spot, not to bad. The entire transmission calibration is going to need tuned as well to raise shift points and keep engine in RPM range. Stock trans calibration keeps motor pretty much at/under 1500 RPM, you need it above.

    Then to feed this beast enough fuel for 5500 RPM you are going to need 15 PSI of fuel pressure. Stock pump should do it but your going to need a adjustable regulator or make one.
    http://www.gearhead-efi.com/Fuel-Inj...sure-Regulator
    Springs
    http://www.gearhead-efi.com/Fuel-Inj...rings-Measured

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  10. #10
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    Well I regret to say I waited 10 years to the month to look into this again. I had many private messages with EagleMark back then and never pulled the trigger to get this done. I see now he has passed away and I’m sad for that, and my dad passed away in 2015. I gave this truck to my little brother, it was his pride and joy until he got t boned and it bent the frame in 2020. The truck sat in a field for 3 years with no front clip, I decided to rebuild it as a surprise starting in may.

    I got a new frame and swapped it over, freshened up literally everything, trans rebuilt, rust cut out and welded up, it’s going for paint in 2 weeks.

    The truck is still the exact same configuration as when EagleMark and I spoke last. It’s running rich as hell. I still need to plug the knock sensor in and then check codes.

    Is there anyone willing to dive into this for me and get me a chip? RIP EagleMark
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  11. #11
    First you're going to have to get the sensors right so there is no trouble codes with the key on engine off. A scan tool is great to get your initial setup but you will need a tuner program to dial it in.
    I recommend downloading tunerpro rt and buying a aldl cable to link it with your computer. Were you able to find out what PCM you have? Do you know about what year the vehicle the PCM came out of? Might help to narrow down what it is.

    That will be necessary to find the correct XDF to read the .bin and the correct ADX for the laptop and PCM to talk to each other. Buying one chip may make it run better but it will probably require several burns to dial it in.
    I'm just learning this stuff too so others will probably chime in and fill in the gaps. I ain't old enough to know it all.
    Last edited by scooterwrench; 09-19-2023 at 02:20 AM.

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