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Thread: 70 duster small block, 7727 ecm $8d

  1. #1
    Fuel Injected!
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    70 duster small block, 7727 ecm $8d

    im thinking that I need to start a thread to keep everything in one place instead of cluttering the board with all sorts of posts.

    im starting the hardware install/injection conversion around Christmas. this has been years in coming.

    what I already have:
    7727 ecm, harness, distributor, and sensors from a 91 corvette.
    1200cfm throttle body, with progressive butterflies
    lean burn mopar distributor (will convert using the tpi distributor)
    msd box
    ls1 injectors, ls6 injectors, and red top ford injectors
    adjustable vacuum referenced fuel pressure regulator
    edelbrock fuel rails
    victor jr with injector bungs welded in
    01 Malibu fuel pump module (there's a thread in the how to section asking about this)
    3/8 feed and 5/16 return lines


    hardware questions:
    1. I need an oxygen sensor. I have long tubes. I need a heated sensor, correct?
    2. can I use a wideband with this ecm, and if so, should I? and is there a factory replacement one that would be recommended?
    3. which set of injectors should I use?
    4. other than MAP, TPS, IAC, CTS, IAT, 02, are there any sensors I need to keep?
    5. do I need a knock sensor? I have a solid roller cam in the car, and im worried about false knock.
    6. any reason not to use jegs pro-flo extreme braided nylon hose? its lined, and good looking. but what black fittings?
    7. how hard do the hold downs need to exert pressure on the fuel rails?
    8. should I skip monkeying with the factory malibu module and just go to a tanks pr4?

    anything im missing?

    ive done multiple efi engine swaps, but its always been a stock transplant. like a l98 into a 55 chevy, or the tbi into an old truck, etc. never a mix and match roll your own setup. I

    ve been impressed with the dual pump/surge tank setup I normally use, but im extremely space limited in this car, and don't want my surge tank in my trunk. so I want to go in-tank. with me coming up on unemployed in feb, I want to do this as cheaply as realistically possible. so no super expensive fuel system stuff please. 250 for the pump setup would be about max.

    what am I not thinking of/anticipating on the install/hardware side?

  2. #2
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    I love to do builds on the cheap. In fact, for my own it's usually a matter of necessity. If the Malibu sender will provide enough fuel then use it. I shy away from the pump module assemblies because pump replacement requires buying a complete new sender or a pump kit from Ebay with an unknown pump. But many people have had success so it will probably work. I've seen 3/8 fuel line on engines producing 700 hp. I probably wouldn't do it that way at that power level but it serves as an upper limit for what's possible.

    I'd install the knock sensor. It might give a false signal and if so it's easy to disable or disconnect it. Much easier than trying to add it after the harness is built and the engine is installed.

    It would help if you could install a VSS. Many ecm functions are keyed to vehicle speed.

    I have used non-heated O2 in long tubes but switching to a heated versions will help ensure the sensor stays warm and provides a valis signal. WBO2 might be usable depending on what code you're using and what sensor you have. Most likely you will need a sensor that will simulate the NB sensor to fool the ecm. Stock O2 voltage ranges between 0 and 1V so your WB needs to produce a similar signal to be compatible.

  3. #3
    Fuel Injected!
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    I do have a vss built in to the tremec 3550 that's in the car. And this one is on an extrrme budget. Im out of work come February if I don't find another job. And anything else in my area is going to be a pay cut for the first couple of years.

    Looking at the specs on the Malibu pump module, there's no way it will feed the small block mopar. So either i swap the pump, or go pa4. For the extra $75, seems like the pa4 will be much less headache.

    Will I be able to effectively tune with the heated narrow band 02? And should I get a 3 or 4 wore? The three wire are a hell of a lot cheaper than any wideband I've found.

  4. #4
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    I started out with carburetors and mechanical distributors doing plug cuts and checking exhaust smoke color. I think a person can do a reasonable job of tuning with a narrow band if he/she pays attention to what the engine is saying. There's a lot more to watch though and you should be careful about trying hard to be sure you interpret the results correctly. Don't expect perfection but you can make it drive on the street extremely well if you dedicate enough hours to it. I like a 4 wire sensor as you don't have to rely on the exhaust system for a ground path.

  5. #5
    Fuel Injected!
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    Ok. 4 wire it is. I like the idea of not depending on the exhaust to ground the o2 sensor.

    And so what you are saying is that if I treat tuning like i would a carb and normal distributor, a narrow band will be fine. I can do that. I've gotten decent at tuning carbs, and plug reading, and vacuum tuning, and. ...

    Do you have a chart of what tables in $8d equate to carb tuining changes? Like accelerator pump shot is? Idle screws are?

  6. #6
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    Do you have a chart of what tables in $8d equate to carb tuining changes? Like accelerator pump shot is? Idle screws are?
    <sigh>

    I've been talking about building tuning software for carb guys for years. Something that would show dials and sliders to represent jet sizes, accelerator pump, choke stove... all sorts of things a carb guy would get. Too bad I don't even have time to take care of the high priority projects around the house.

    There are steps to follow that will help. Set the engine displacement and injector flow first. You can use the main timing table to set up a curve like original including both vacuum and mechanical advance. It will be far from optimal but it can provide a starting point. Then you can set VE to roughly match a hp curve if you have one. That's a very simple way to start. Adjusting PE or Power Enrichment is like playing with the Power Valve. Acceleration Enrichment or AE covers the same function as the accelerator pump. You will find that some of these tables overlap in ways that you didn't have to think of with a carb, and you will also find there are tables that don't directly relate to any adjustments you had to do with a carb system.

  7. #7
    Fuel Injected!
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    new questions:

    ignition is going to be ecm controlled. I have no issues in adapting the gm module to the mopar distributor (same trigger sensor between the two). matter of fact, I rebuilt and mmodified a distributor today to do just that.

    but now comes the MSD box/coil quandary that ive been avoiding.

    car has had an MSD 6ALN on it for many, many years. also a blaster coil (round style, with just pos and neg wiring hook ups).

    eve been reading that the ECM needs to see the two pigtail stock GM coil that looks like a block. I have a few of them , so sourcing is no trouble.

    but I cant figure out how to wire the msd box into the system, wether or not I even should, and if I HAVE to use the square coil, or can use the round one.

    ideas?

    I'm actually trying to finalize the last few little details on the bench, test the system with tunerpro to male sure everything is ready to rock, and get the swap started this week.

    heres a link to the build thread, efi stuff is towards the end.

    http://www.forabodiesonly.com/mopar/...d.php?t=111545

  8. #8
    Super Moderator Six_Shooter's Avatar
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    You can use any coil you want.

    Connecting the MSD into the system is easy as well./ In the MSD instructions it has diagrams that explains how to do it, just use the ones based on GM ignition, as in pretend your engine is a GM engine when looking at the diagrams, because electrically it will be. ;)

    To break it down though, you connect the white wire from teh ICM that would connect to the coil to the points trigger input of the MSD box, the pink wire that would attach to the coil will attach to the small red wire of the MSD box for ignition, and then the orange and small black coil wires from the MSD box connect to the coil. It's really that simple.
    The man who says something is impossible, is usually interrupted by the man doing it.

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