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  1. #1

    Default GT40 heads with CFI

    Been doing some searching around this forum about this and the consensus seems to be that the CFI can't handle this combination with out problems. Anyone have experience with it? Here's what I'm planning to do:
    Re gasket explorer long block
    Alex's parts valvesprings
    Stock 86 GT cam (stock rockers)
    Reuse the CFI until I get time to swap to SEFI

    Is this possible without a lot of problems?


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  2. #2

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    I would go for it. Ltd LX cfi I am assuming?

  3. #3

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    I ran a roller motor in my LTD with the stock CFI unit and it always ran very lean, it detonated like crazy on the top end. The CFI can only dump so much fuel. Even tried adjusting the fuel pressure with no luck.

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  4. #4
    FEP Super Member xctasy's Avatar
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    Default

    Depends on what goes with what. If you run an Explorer roller cam ( which is very mild), and the GT40P heads, CFi will work great.


    Any stock GT Roller cam with GT40P's is likely to result in problems.


    The GT spec roller cam or orginal flat tappet cam with CFi won't like the high flow GT40P heads. In fact, any porting at all to the E7 heads with a GT Mustang Roller cam , it'll be outside the limits of the EECIV calibration.


    Quote Originally Posted by xctasy View Post
    Welcome!


    Your 5.0 HO automatic block is roller capable, but was not ever roller equiped.


    Roller cams and CFi work together fine, but you cannot use high flow cylinder heads. Stock, or E7, fine. As soon as it gets GT40 or GT40P's, the intake valve flow speed changes and causes poor idle. Same with exhaust. You can really go up in size and type, but there is a limit, and then the whole shootin match won't work with the stock fuel and ignition setttings.

    But roller cam, yes, even a B cam. But never with high flow heads, because it was designed around the stock 157 to 225 hp cam lift and head flow rates.

    Since its speed density, it can acommodate improvments, but because its speed density, you can't go too far. Past the stock 130 cfm intake manifold flow, it gets ropey. The Ford engineers made the 5.0 HO EFI Central Point injection quite unlike any other 1980 to 1985 CFi system.


    They deleted the IAC/ISC systems, and the VOTM is used in a very different way, as is the choke pulloff, which is the principal difference, again proving what makes them for me the culmination of the very best minimum Fo MoCo engineering ever. Leaving out a part, and using another exsiting system to get a better result...that's smart!


    Information from MANY experienced sources on this...most bail on the system very early because of a lack of good, proven info.

    http://vb.foureyedpride.com/showthre...98-1985-ltd-lx
    http://vb.foureyedpride.com/showthre...et-issue/page2

    I was able to find the original artilcle, from Jo Peterson; it affirms the maximum allowed head, exhaust and cam swaps for much heavier AOD Ford LTD LX HO CFi's

    fgross2006 copied the exhaust suggestions, so did never, who had haunting with a B cam and the big exhaust. Seams like just a little loss or gain of intake or exhaust scavenging, and you can over cook it, but this is what works below.

    http://home.earthlink.net/~jopeterson/
    http://home.earthlink.net/~jopeterson/Mods.htm


  5. #5

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    Quote Originally Posted by nelzfoxes View Post
    I would go for it. Ltd LX cfi I am assuming?
    Yes LTD LX cfi and it isn't going to be on forever just a couple weeks to a month. And will usually only get driven around town


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  6. #6

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    If you look at the cam specs the HO CFI cam (sometimes called the Torino cam) is closer to a stock 85-87 Mustang HO roller cam than it is to an Explorer cam.

    I know of several Mustang longblock swaps with CFI that ran fine. Plan to try GT40 P muself with it next year.
    1985 LTD LX original owner

  7. #7

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    If it were me, I'd go for it. I'd think of the cfi system more like an sd setup. Yeah it has two big injectors on top of a toilet bowl, but it does have some fuel trim adjustment. You can bump up timing (or restart it if needed) and slightly raise fuel pressure. If you keep the stocking cam it shouldn't lean out except for at wide open throttle and the vacuum should stay the same.
    2 1986 cougars (both 4 eyed and 5.0)
    1 1987 cougar

  8. #8

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    Years ago i converted a 95 Chevy truck from a from a 4.3 V6 to a 5.7 V8. I was surprised to realize that the throttle body unit was identical and the two big injectors were the only difference. Ive looked at my CFI and i swear those injectors are the same. So id be wondering if you could swap injectors to a larger size?
    Dan

    1985 Lincoln Continental. T-5, Bullit wheels, Mustang springs and Hybrid Lincoln/Mustang control arms, 8.8 w 3.27s, Cobra swaybar, adjustable struts and shocks....

  9. #9
    FEP Super Member xctasy's Avatar
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    Yes, you can swap the injectors. But there are serious over shoot issues to do with cylinder to cylinder flow distribution, the CFi system is notorious for having issues in the 165 hp CFi squad car LTD LX's and LTS variants.

    Ford's injectors are not dedicated designed injectors, they are common Bosch injectors sourced under a Ford part number to clip into a fairly standard housing. The Motorcraft CFi unit lookes the same, but the throttle bodies differ in the same way 1.08 and 1.21 Motorcraft 2150 carbs do, and that means they aren't interchangable between the various year CFi V6's and the three kinds of CFI 5.0's

    There are at my last count 13 varieties of ECM,
    three kinds of throttle body, and
    three kinds of Type 2 Bosch Injector.

    The 3.8 V6 and non HO 5.0's have IAC; the 5.0 HO's are EECIV, and the HO idle is by TFI PIP/SPOUT, which pulls out idle advance to control idle speed.

    Yes, you can use parts, but to do so involves the risk due to serious minor changes regarding the flow control brackets that bias the injector shots to each cylinder, and a running Technical Service Bulletin upgrade to the 1984 non HO gasket which prevents simple parts swaps. Idle tracking problems with CFi's require 100% right parts to fix the DTC codes...any little changes will have it firing codes, and you'll not be certain what caused them.


    Yet if everything is standard, a 5.0 HO it'll cope with big over sized exhausts, all the larger roller factory non letter cams, non standard 2-bbl intakes, big bore short or long headers and E6 High Swirl or E7 heads, but as soon as you improve the cylinder heads flow speed, lookout!, the Speed Density EECIV chops out as per jopeterson's experience above.

    CFi has a very specific engine tune, and although they all look the same, the injectors and air flow and electronics are all subtly different. And beware; the EECIII system remained on line till, IIRC, 1984 for California XR7's and Thunderbirds, so what you think you are getting from a common spare parts car could be different. The whole ignition for EECIII's runs of a Crank Position Sensor and a frontal lobotomy Duraspark III with no sping internals, and a huge external control box , while the EECIV uses TFi.

    All V6's which were CFi were EECIV, but the idle Air Control system makes it different to the the 5.0 HO.

    The Standard Output EECIII or EECIV 5 liters have smaller throttle bodies,as well as smaller lb'hr injectors, and a different firing order. Everything was custom to application, not like the 4.3/5.7 3/4rs V8 realtionship.

    The Delco/CalPac P4 ran a very simple different kind of injector, not the same as Fords 80-86 systems.
    Here's a whishfull post right here

    http://www.foxtbirdcougarforums.com/...r-EEC-IV/page4
    just thought of something.. isn't the 3.8 CFI EEC-IV harness the same as the 5.0? just the harness, i know there's obviously a difference in injector size, TB size and EEC.. reason i ask, i may be buying an 85-ish (not 100% certain the door tag is correct to the car) bird with a dead 3.8, if the guy will take my offer..

    if they're indeed the same, i think i just might go with my plan of dropping a 302 in it and attempt to tinker with the EEC-IV system to nail down a solid setup, before installing it in the heritage and converting this car to carb.. crossing my fingers that he accepts 350-450 for the car
    The 3.8 CFi verses 5.0 SO CFi has different pinouts, different calibration, different injector sizes, different knock sensor, different EGR, even though things look as similar as "same" can be.

    We all want Fords CFi to work, but its 2-bbl Motorcraft Central Fuel Injection is 100% dedicated to its application....

  10. #10

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    Killer info xctasy!!
    Dan

    1985 Lincoln Continental. T-5, Bullit wheels, Mustang springs and Hybrid Lincoln/Mustang control arms, 8.8 w 3.27s, Cobra swaybar, adjustable struts and shocks....

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