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What parts do I need?

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  • What parts do I need?

    Look here for threads on what parts you need to get started with your FI conversion.
    To start things off, we are referring to the 88-91 GM TBI systems. The primary system being from a truck, van, or astro van with 4.3 or larger engines and using the 1227747 ECM. If you do get the 4.3 V-6 ECM, you will need to replace both chips in it with the V-8 chips. You may find some 87's and some 92's with the same system so look close. As a secondary you can use the 1228746 computer from the cars but will also require the use of the IAT inlet air temp sensor. Normally mounted in the air cleaner housing.

    If you are pulling the system yourself then pull everything off the motor that the harness is attached to! You can throw the unneeded away later.

    Basic system:
    1. Computer- better known as the ECM. 1227747 or 1228746 You will need someone to program a chip for you to optimize the computer to your engine.

    2. Throttle body- TB- the 4.3, 5.0 and 5.7 TB's are all the same CFM with 1 11/16" bores. The injectors are different.
    The 454 is larger with 2" bores.
    I would recommend a TB from about the same size engine or larger. 304/345 use 5.0/5.7. If you run a cam/springs and headers then maybe the 454 TB. 392 can use the 350 or 454 TB.
    Our motors turn so slow that you can actually tune a 345 to the 305 system.
    Here's the math thread to verify the data. MATH

    3. Wire harness-pull from any donor vehicle above. It will need to be modified to fit your application.

    4. Temp sender-CTS pull from donor or buy new.

    5. O2 sensor- You could pull from donor but a new one is cheap.

    6. fuel pump- You have a choice to modify your tank for an in tank pump or mount one external to the tank. I use the Masters E2182 from AZ. $75

    7. Fuel pump relay- From donor vehicle with the harness. Hopefully

    8. Pwr relay- I use the small bosch style aux lighting relays from AZ about $4 I think they are called Baja's.

    9. Adapter plate for the TB- you can make one or buy one.
    Spreadbore 4V- Holley 17-41, Transdapt2206 and 2207
    Squarebore 4V- Holley 17-45
    2 barrel- Holley 17-47, Transdapt 2204 and 2205

    10. Distributor/EST- For FI you will need to decide if you want a complete conversion (fuel and timing) or partial (fuel only).
    For full you will need a distr with a magnetic pick up. You have 2 choices.
    a. The duraspark conversion. DS Distr conversion EST is mounted external
    B. The small cap EFI distr. Small Cap EST is mounted internal

    11. MAP sensor- this senses the change in manifold pressure. it usualy is mounted on a plate bolted to the intake manifold. You can modify the plate and remount it on the IH or make a plate and mount it on the firewall.

    For the partial conversion you will retain your stock distributor.

    12. If using the 1228746 ECM you will also need the IAT. Inlet air temp sensor off the air cleaner.

    1. Knock sensor- Screws into the side of the engine. Get from donor.

    2. Knock control- ESC this sends the signal from the Knock sensor to the ECM to reduce the timing if it hears a ping.

    3. Speed sensor- VSS sends the ECM the cars speed.

    4. EGR solenoid- If you need to run emissions on your scout.

    Jeff Eggemeyer's donor vehicle list.
    Donor List

    Thanks to snflupigus for some pics. He has a lot of them.
    Last edited by Bill usn-1; 11-29-2005, 11:05 AM.
    Bill USN-1

    May be the answer to all your fuel injection needs!
    Learn to do it right.

  • #2
    To look up replacement parts go to or and use an 88-91 chevy 1500 with a 350 automatic.

    Fuel pump try an 89 ford f250.

    Or for used parts your options are I use a guy named Steve for sets of sensors or parts I don't want to pull myself. His EBay username is ragged and he has his own ebay store now.

    or for a complete junkyard network on the web.
    use the same vehicle for look up.
    Last edited by Bill usn-1; 08-02-2005, 01:25 PM.
    Bill USN-1

    May be the answer to all your fuel injection needs!
    Learn to do it right.