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4.3 Ecm/computer Auto To Manual Conversion

Discussion in 'Builds and Fabricators Forum' started by 47v6, Oct 29, 2019.

  1. Oct 29, 2019
    47v6

    47v6 junk wrecker! Sponsor

    Washington DC.
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    I am installing a 2000 4.3 Chevy into my CJ2a. I will be using a manual transmission and this engine from an Astro van is auto.

    I will need to either have a reprogrammed computer or some other way of engine management to control the fuel injection and the lack of the auto transmission.

    What have you done? What worked and didn't. Were you able to reprogram it yourself or send it off? Did you just get an ECM from a manual?

    Look forward to your replies.
     
  2. Oct 29, 2019
    Norcal69

    Norcal69 Out of the box thinker 2019 Sponsor

    Cottonwood, Ca
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    The black box ecm is a little bit more of a pita than the later models. In order to reprogram it you need to have a program like EFI live or Auto Cal. I'm sure there more software options out there. You can also change to the 0411 ECM which in infinitely tuneable and easier to work with. My vortec 350 "L31" is the same basic ecm/ injection setup as your 4.3. When I put the manual transmission in my 99 Tahoe, I used Justin @ Black Bear Performance :: Custom Tuning Solutions for 96 and newer GM Vehicles
    At the time he was just starting out.... nearly 10 years ago..... I shipped him my black box ECM, he re flashed it for the manual transmission and installed a performance tune. At the same time he removed the speed governor, and most important the "torque management" function.
    California smog checks require plugging in to the OBD2 port and communicating with the computer.... everything has to line up vin, ect.... Justin made it all work.
    After your initial tune and you are driving around, he can send you a scan cable for data logging and further fine tune your setup.
    This is just my experience. I'm sure that there are "flashers" closer to you that can do what you need.
     
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  3. Oct 29, 2019
    47v6

    47v6 junk wrecker! Sponsor

    Washington DC.
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    Black bear seems to be the top of the line for this. I want everything to work, Cats, EFI etc.. I want it to work correctly the first time too. I will be giving your guy a call.
     
  4. Oct 29, 2019
    mortten

    mortten I can’t put my finger on it

    Peninsula, Ohio
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    Make sure the VATS gets disabled also.
     
  5. Oct 29, 2019
    Norcal69

    Norcal69 Out of the box thinker 2019 Sponsor

    Cottonwood, Ca
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    :schooled: This is what I was struggling to remember the name of...... VATS/ Pass lock can be a headache to relearn if using a new to you ECM.
     
  6. Oct 29, 2019
    Dphillip

    Dphillip Sponsor Sponsor

    Omaha NE
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    I believe all you need to do is take the prom chip out of your automatic EMC and install a prom chip from an EMC with a manual tranny.
    When I installed my 4.3 the motor came from half ton Chevy truck with a 5 speed. I put a 700R4 behind the motor and it wouldn’t shift correctly. I limped down to my friends transmission shop and he plugged a scanner into the diagnostic port and knew in a second I had a manual transmission chip in the ECM. I drove straight to the junk yard and purchased a ECM from a S-10 Blazer with an auto, swapped out the proms and it’s shifted perfectly for the last 20 years.
    My engine and transmission are 1993 vintage so I don’t know for certain about you 2000 model.
     
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  7. Oct 29, 2019
    Norcal69

    Norcal69 Out of the box thinker 2019 Sponsor

    Cottonwood, Ca
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    The later model computers have to be re-flashed for the manual transmission.
     
  8. Oct 29, 2019
    47v6

    47v6 junk wrecker! Sponsor

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    What do i need to keep from the interior of this astro van? Anything? Everything? I can't actually use things like the Ignition switch or steering column, so what do I need to make this work?
     
  9. Oct 29, 2019
    Boyink

    Boyink Super Moderator Staff Member Sponsor

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  10. Oct 29, 2019
    Norcal69

    Norcal69 Out of the box thinker 2019 Sponsor

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    That I don’t know...... I think you should be able to eliminate allot of the harness and have the tuner “turn off” anything unnecessary so the engine will stand alone.
    Similar to what Ryan is doing on the Varg, but with more computer. Your probably going to need to dig up the wiring diagram for the Astro.
     
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  11. Oct 29, 2019
    47v6

    47v6 junk wrecker! Sponsor

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    I didn't want to completely take apart the dash to remove ALL the wiring, but I need to just do it. Cant be lazy now or the future will be very irritating if I don't have that *one* thing I needed..

    I emailed Black bear to see what they say. I WILL have to have someone program this ECU for what i want. Might as well use them, they seem to be good.

    Engine harness is off, labeled and intact. Alt has a bad bearing, A/C clutch sounds like its made of gravel and the waterpump bypass is almost rusted through. The front of the engine is bare now. Serpentine systems are so much better.
     
    Last edited: Oct 29, 2019
  12. Oct 29, 2019
    ITLKSEZ

    ITLKSEZ Volvophilic

    Post Falls, ID
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    That’s a good point. Do you want to retain the OBD2 capabilities? Check engine light?

    Edit: Mine is pre-OBD. It only has a test port for the Lamda Sond system, which I retained. If I had the OBD2, I probably would have worked to retain it.
     
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  13. Oct 29, 2019
    47v6

    47v6 junk wrecker! Sponsor

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    I do want the OBD2 stuff. Why not? It's there..I want to retain everything i can to make it as modern as possible with the least amount of problems.
     
  14. Oct 29, 2019
    scott milliner

    scott milliner Master Fabricator

    Seattle Wa.
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    I bought a factory service manual for the S-10. This had all the wiring diagrams I needed to eliminate wires. So being I already had a GM wiring harness in the jeep. I only needed the fuel pump relay and OBD2 connector.
    Then I stripped the engine harness to only use the wires I needed to run the motor. Oh. Try to reuse the Astro fuel lines. May have to use heat shield tubing to keep them cool from the exhaust. I didn't do this and had a hard time installing later.

    This is my Check Engine Light. (Buick Regal)
    [​IMG]
     
    Last edited: Oct 29, 2019
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  15. Oct 29, 2019
    47v6

    47v6 junk wrecker! Sponsor

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    The astro fuel lines I cut. They were rusted to almost failure. These did not have heat shielding on them.These ran directly down the back of the engine across the top of the transmission. This engine and the van itself is very rusty. There was not much holding the front of the subframe on and the rad support was almost gone around the mounts.
     
  16. Oct 29, 2019
    scott milliner

    scott milliner Master Fabricator

    Seattle Wa.
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    My S-10 didn't either, but being my Jeep has the exhaust running down that side. I had to add them. I could hear the fuel bubbling in the tank after I shut the motor off.
     
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  17. Nov 2, 2019
    Keys5a

    Keys5a Sponsor Sponsor

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    I don't know when the change took place, but the late-'80's/early-'90's ECUs had a small cover to get to an EPROM that could unplug and swap easily. The later ECUs don't have this feature, and need to be reflashed. My '97 ECU is the later type.
    -Donny
     
  18. Nov 2, 2019
    Norcal69

    Norcal69 Out of the box thinker 2019 Sponsor

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    Your correct. My 99 required a re flash. I believe that the re flash came in with the spider injection system in 96.
     
  19. Nov 2, 2019
    47v6

    47v6 junk wrecker! Sponsor

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    I will need to reflash it for sure.

    Another question. The Astro van uses hydroboost. Where and how to I get a vacuum port for the brake diaphragm on the intake of this engine?
     
  20. Nov 2, 2019
    Oldriginal86

    Oldriginal86 Member

    Pasadena, Md.
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    I think the eeprom went away when OBII came out.
     

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