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Thread: Mechanical Fuel Injection Help in New England

  1. #1

    Mechanical Fuel Injection Help in New England

    Looking for recommendations for experienced Mechanical Injection service in New Hampshire , Vermont, Massachusetts, Maine or anywhere else close by.
    Thanks
    Dennis

  2. #2
    Rick Cabell on this forum. Near Burlington, VT.
    Steve Shea #1 joined a long time ago
    58 speedster
    66 912
    67S
    73S
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    1132 honda snowblower

    member Jackson Hole Ski Club

  3. #3
    Senior Member lopena's Avatar
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    Also consider Automobile Associates in Canton, CT (west of Hartford). The last time I visited them (in July) their shop was heavily populated with MFI cars.

    Alan
    N.J.
    Alan
    New Jersey

    1969 911S
    1964 E-Type roadster
    1987 M6 coupe
    1988 328GTB

  4. #4
    member #1515
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    What issues are you trying to resolve?
    David

    '73 S Targa #0830 2.7 MFI rebuilt to RS specs

  5. #5
    My main problem is a hesitation at very low throttle, like not enough fuel? Runs great when you open it up. This is a 1970 911E ,
    The car was taken out of storage about 4 years ago. Prior to that is was an in-op for quite a while. New gas tank, fuel pump, throttle bodies cleaned and freed up . and all the typical other problems of a car that sat. It has been run for about 4,000 miles over the past 4 years. I have run probably 4 or 5 Techron treatments through it. It has had the same problem the whole time no better / no worse.

  6. #6
    member #1515
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    Have you checked your distributor advance mechanism.
    Try a few tank fills with stabil.
    A thousand miles a year is not much to keep everything loose in the injection pump.
    David

    '73 S Targa #0830 2.7 MFI rebuilt to RS specs

  7. #7
    I came across this information in a detailed description of MFI set up and adjustment:

    "Even though the Bosch PE system is known for its response
    and horsepower it is well known for its part throttle driveability surging."

    This seems to be the exact symptom my car has. I also have a 1973 911 S but it does not have the partial throttle surging that the 1970 911E has. Was there an improvement with the 2.4 engine? I know the distributor has added vacuum advance ,. Anything else?

  8. #8
    member #1515
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    Well the 2.4 has more torque. The 2.2 really needs more revs to perform properly. You really can't lug either one.
    Surging is different from hesitation.
    David

    '73 S Targa #0830 2.7 MFI rebuilt to RS specs

  9. #9
    Senior Member NorthernThrux's Avatar
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    MFI tends to run best rich. You'll see most people who are skilled in the art of MFI tuning disregard the CO readings that are mentioned in CMA and set things a bit richer. This is in large part to overcome the part throttle hesitation. YMMV (literally!).

    But running though CMA systematically is essential before setting that final mixture ratio.

    My MFI is set 1.5% higher on the CO number than recommended I believe. Runs flawlessly with no hesitation anywhere in the rev or throttle range.
    Early 911S Registry # 2395
    1973 Porsche 911S in ivory white 5sp MT
    2015 Porsche Macan S in agate grey 7sp PDK

  10. #10
    Quote Originally Posted by NorthernThrux View Post
    MFI tends to run best rich. You'll see most people who are skilled in the art of MFI tuning disregard the CO readings that are mentioned in CMA and set things a bit richer. This is in large part to overcome the part throttle hesitation. YMMV (literally!).

    But running though CMA systematically is essential before setting that final mixture ratio.

    My MFI is set 1.5% higher on the CO number than recommended I believe. Runs flawlessly with no hesitation anywhere in the rev or throttle range.
    Until it gets too rich! My 70S was readjusted by a well known restorer, and it started backfiring when unloaded coming down in rpm at 3000-3500 rpm.

    When set up correctly MFI is amazing.
    The early Sís...

    1967 S Coupe
    1970 S Targa
    1973 RS Coupe (an honorary S?)

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