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Is anybody running a 383 w/TBI or MPFI?

Discussion in 'The Garage' started by Derf00, Jun 23, 2002.

  1. Derf00

    Derf00 1/2 ton status

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    Is anybody running a 383 w/TBI or MPFI in a computer controlled Balzer or JImmy? I have some questions.
     
  2. HarryH3

    HarryH3 1 ton status Author

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    Yep. I've got an '87 Corvette TPI top end bolted to a 383 block. /forums/images/icons/cool.gif What do ya need to know?
     
  3. BIGRIG

    BIGRIG 1/2 ton status

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    I also have some q?'s getting ready to do this myself. What tank? and what # computer did you use? also is there any helpful literature, sites or tips?

    Thanx didn't mean to butt in on the post. /forums/images/icons/frown.gif /forums/images/icons/wink.gif

    Chris
     
  4. BurbinOR

    BurbinOR 3/4 ton status

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  5. Derf00

    Derf00 1/2 ton status

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    Not a problem, the more info the better. I will soon transplant a 383 w/MPFI into our '90 Jimmy and am looking for as much information as possible.
     
  6. HarryH3

    HarryH3 1 ton status Author

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    I just dropped in a set of larger injectors to deal with the higher fuel requirements. I'm still running the stock Corvette chip. But my setup has the Mass Air Flow (MAF) meter, so it can deal with a pretty wide array of engine changes without choking. The stock truck setup uses the Manifold Absolute Pressure (MAP), which requires that the chip be programmed pretty close to what the engine needs. Some TPI systems also use the MAP sensor, so the chip needs to "know" about the engine on those. One thing for sure... 383's ROCK! /forums/images/icons/cool.gif
     
  7. lizard

    lizard 1/2 ton status

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    Here's all I know... well almost. You will want to reprogram the computer. absolutely. You cannot trust someone to do it (correctly) via mail so get a eeprom burner, a uv eraser, a soldering gun and head to www.diy-efi.org/gmecm for the details on reprogramming.

    I'm doing the same swap eventually - as I get the time. There are two factory designs to choose from the '85-89 MAF style and the 90-92 MAP type. For a truck you'll want to ditch the sensitive MAF and go with MAP. MAP is cheaper and more reliable in high vibration environments. There is a memcal/prom available for the 1991-1992 350/700R Firebird that is the best baseline for the swap but you will have to reprogram it for best results. If you take the time to learn how to reprogram the prom you'll have the best setup imaginable. Go ahead and plan on getting a vehical speed sensor (VSS) or the idle will never be totally right.

    If you are interested in the TPI manifold setup you'll be limiting the rev's to around 4500RPM cause it don't breath too well at higher RPM's. A 383 may overtax the factory setup - start porting now /forums/images/icons/smile.gif I hear the best place to start is behind the throttle body (smooth out the lumps but don't go crazy) and then port match the plenum, runners and finally the manifold. If you go for an aftermarket manifold, convert a single plane manifold (more expensive) and put a 1000cfm TB on it. You can still use the factory TPS...

    You really need to get the right fuel system (with a real return line). Converting the factory tank is one way to do it but I am leaning to using a 88-91 Blazer tank so I get the benifit of the factory fuel pump and baffling. Without baffling you have to keep the tank 1/2 full to avoid starving the engine on steep inclines.

    Finally you need to plan on hooking up the EGR and charcoal canister -yep emissions stuff. Unless you are willing to rewrite the eeprom code in assembly language (forget it unless you have 20 years experience - then it's still nearly impossible) you need to keep as much factory hardware as possible.

    The benifits of using factory hardware is you can get replacement parts anywhere and you can reprogram the eeprom with a little effort (learn how). Once you get everything together you can remap the fuel curve and spark table to best meet your engines needs...

    regards,
     
  8. HarryH3

    HarryH3 1 ton status Author

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    I'm still using the stock 1975 K5 tank. /forums/images/icons/cool.gif Just outside the tank, mounted inside the frame rail, is a Bosch external fuel pump from a Jaguar V-12 application. My computer is the stock '87 Corvette ECM that came with the original engine. /forums/images/icons/cool.gif
     

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