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Thread: Cross Fire tuners please help

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  1. #1
    Fuel Injected! uncabob's Avatar
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    Cross Fire tuners please help

    Newby tuner with 84 Vette XFI l83 engine (was 205 HP) against a th400. Original block and heads.
    Using 5235206(61pph) injectors plumbed in parallel with external FPR and original TBs.
    Old FPR and accumulator blocked with plates.
    New cam is supposed to be a little hotter (asked for RV cam).
    No EGR or CATs yet but expect to add later.
    Cast iron exhaust manifold with 2.5 in. collector reducing to 2.25 in. pipes with X style x-over
    Using tunerproRT v5 and 27FS512 chips and AKAH starting bin.

    Need to know where to start timing. Have to advance over 45 deg just to get it to start.
    Can,t keep it running long enough to get a timing light on it.
    Runs way too rich, really rough and won't stay running.
    How do you disable CL?
    What BPW should I start with? Was 135 but set at 118 at present. FP is down to 9psi and still too rich.

    Any XFI tuners want to jump in?
    Last edited by uncabob; 08-22-2016 at 02:38 AM. Reason: had wrong injector number
    Don't force it, get a bigger hammer!

  2. #2
    Super Moderator Six_Shooter's Avatar
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    So you have a '7747 ECM installed?

    Are you using the adapter that was sold for this swap way back when? Or did you splice into the original harness for the new connectors?

    What do you have base fuel pressure set to?

    To disable closed loop (which won't be a factor until the engine is almost fully warmed up) you set the closed loop enable temp to maximum (255 degrees).

    I moved this to the GM tuning forum since it's more of a tuning question than a Tuner Pro question.
    The man who says something is impossible, is usually interrupted by the man doing it.

  3. #3
    Fuel Injected! uncabob's Avatar
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    [QUOTE=Six_Shooter;61523]
    So you have a '7747 ECM installed?
    using the adapter
    What do you have base fuel pressure set to?
    Yes the '7747
    Using the Moates adapter. (G2?) and Autoprom APU1 with 27fs512 chip.
    BPW is set at 118. Tried 128 suggested by 1project2many but still had a lot of smoke out of the exhaust.
    Somewhere I saw 118 suggested and am trying that. Think it was DaveW for something he was writing about.
    Engine and trans are setting in the frame but no cab, bed or fenders. Can't make any logs yet because I haven't been able
    to get my laptop working with tunerprort yet.

    Thanks for the quick reply.
    Bob
    Don't force it, get a bigger hammer!

  4. #4
    Super Moderator Six_Shooter's Avatar
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    Oh so this engine is not in a Corvette or F-body? So you made your own harness? The adapter I was asking about converts from the edge card style connector to the '7747 harness that was avaible years ago, not sure it still is.

    When you say that you "can't get Tuner Pro to work with your laptop yet" do you mean that you have not been able to get the program loaded or that you haven't been able to connect to the diagnostic datastream (ALDL) yet?

    What is the CEL doing when you turn the key on? Does it flash once, then turn on solid until you start, does it just turn on solid, or does it flash rapidly?

    What was the original application of the '7747 that you are using?
    The man who says something is impossible, is usually interrupted by the man doing it.

  5. #5
    Fuel Injected! uncabob's Avatar
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    Its an old Compaq laptop with XP and I want to bring it up to date. Have an older version of tunerpro on it.
    Doing my flashing on a desktop away from the project. Going back and forth with the '7747 to flash the chip is a bit of a hassle.

    The CEL does as you say. It flashes once then stays on until starting.
    Thanks again.

    The harness was specifically made for the Crossfire. Also forgot to mention that I had the engine running with a
    fair idle about a year ago. Since then I replaced the fuel lines because I wasn't comfortable with rubber lines.
    Last edited by uncabob; 08-21-2016 at 11:32 PM.
    Don't force it, get a bigger hammer!

  6. #6
    Super Moderator Six_Shooter's Avatar
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    Well, to globally reduce fuel you would reduce the BPW (IIRC that's the parameter used in $42). I have found though that low BPWs can cause running issues, unsteady idle, hard to start, etc. IIRC this usually happened around 90 or so for the BPW. You might want to try to reduce the VE table in around where it idles/should be idling in order to reduce fuel instead of playing with BPW. The higher map areas, where starting would also effect might be ok. What is your fuel pressure set at? Vacuum referenced FPR or no? What is the reason behind parallel feeding the throttle bodies?
    The man who says something is impossible, is usually interrupted by the man doing it.

  7. #7
    Super Moderator Six_Shooter's Avatar
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    This is the adapter I am asking about: It's called a "HAM board" Found here: http://www.crossfireinjection.net/catalog.htm



    If you're not using the original crossfire harness though then it doesn't matter.

    Basically my line of questioning is trying to find all of the details of what you're using. When I, and I'm sure most other people, hear "Crossfire" they assume that it will still be in a Corvette or F-body. If that's not the case or things have been changed from original, like the ECM swap, we need to know about this and how it was done.
    Last edited by Six_Shooter; 08-21-2016 at 11:16 PM.
    The man who says something is impossible, is usually interrupted by the man doing it.

  8. #8
    Fuel Injected! uncabob's Avatar
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    Guess I didn't answer your harness question. It was a S&P harness set up for me with the computer and chip as a 1988 chevy truck. I have since
    made some changes in the wiring to use a VSS and a CS10D alternator and fuse and relay panel out of an S10.
    Don't force it, get a bigger hammer!

  9. #9
    Super Moderator Six_Shooter's Avatar
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    I am not familar with their harness, but it was set up for the Crossfire specifically?

    What about the behavior of the CEL? That is a basic function and can tell a lot about what may be going on when an engine conversion doesn't want to start.

    Also the original application of the ECM would help too, since if the NETRES is not correct that can cause impossible issues to overcome where engine running smooth is concerned.
    The man who says something is impossible, is usually interrupted by the man doing it.

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