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Thread: '73S Resto- MFI - Full Tune or Rebuild?

  1. #1

    '73S Resto- MFI - Full Tune or Rebuild?


    Need some advice. My car is so out of tune its a joke. I've had it back to Born2BFast multiple times to fix things, and have now had it to my regular, trusted wrench to fix most of the smaller stuff.

    I'm now down to the biggest issue, the MFI. My wrench, and I've now talked to Alan at the Stable (who I ran into at EASY), bot have said that the MFI needs either a complete tune (~$600) or possibly a rebuild (~$1,500). However, neither can tell me for sure it needs rebuilt, nor that a complete re-tune will make it run perfect.

    My question: is there any way to tell when a MFI really needs rebuilt? I had theinjectors pulled and taken to Pacific for testing. One was bad, replaced and the others are all fine. I know I won't be sorry with a rebuild, but $$ is an issue now (since I've had to spend $$$ to fix crappy workmanship and wornout parts ). My wife's ready to kill me over this thing.

    Alternatively, and I know its a LOT to ask, but are there any kind (knowlegeable) souls in the bay area that would be willing to spend a saturday with a novice (me) working through "Check, Measure, Adjust"? I've read it back to front a few times, understand it, but just don't trust myself to do it. I don't have all the tools needed either.
    Chris Purpura @civilizedmisfit
    Member #479
    Current Cars:
    1972 911T aka The "Civilized Misfit" Build
    Miss February - EarlySRegistry 2023 Calendar
    1968 911S Ossi Blau/Beige Corduroy

    Past Cars:
    2019 911 Carrera GTS (sold, no regrets)
    73S - #1100 (restored and now somewhere in Europe)
    1997 993 Carrera 4S Black on Black (sold)

  2. #2
    If you can't find any help or tools, shoot me a PM. I have most of the tools I can loan and I have learned enough about MFI to get my car running pretty well. I'll help in any way I can. I'd never done anything other than change the oil on a car before I started tinkering around with this stuff so it cant be that difficult. There are plenty of good resources on the web for the porsche MFI stuff.

    I was very hesitant to try to do the work on my car. I brought it to a very good local mechanic who had not seen a MFI car in a long time. Bad move on my part. Don't let anyone who is not familiar with MFI touch your car.

    I'm not a guru by any means, but I'll be happy to try to help or to loan some tools.

    What in the CMA manual is giving you trouble?
    Are all the parts for the MFI system still on the car?
    Which tools are you lacking?
    #711 - expires 12/05
    1972 911T - Sepia 3.2 - For Sale

  3. #3
    I would call Gus at Pacific Fuel Injection and see what he would charge to examine the pump. You take the pump off and take it to his shop. I had my "S" pump rebuilt a few years ago it was around $900. I r&r 'ed the pump. Who qouted you $1500? Or is that to r&r the pump also.

  4. #4
    I once called gus a/b having a kugelfischer (2002tii) pump bench tested.

    he said the current wait is a few months and the cost was not cheap.

    I ended up sending it out and had it rebuilt in a week, some guy in norcal.

    I know gus is the best. but he's got lots of work up there so that option might result in your car being parked for quite some time.

    paul schuster
    santa cruz

  5. #5
    How is the timing? Plugs and wires? CDI good? No need to do CMA if this stuff is questionable. Most of the CMA is very basic stuff. You can see for yourself how the linkage is behaving by moving the linkage bar slowly back and forth (with the engine not running). If everthing doesn't move off 'rest' at the same time, that has to be fixed. Worn out ball joints are not good, but if they are not too bad, the linkage can still be adjusted to 'tight' at first movement. A little survey on your part before diving in with a friend can get you familiar with how the thing works. Next thing you know, you'll be setting those butterflys.

    Only when all this physical stuff is in adjustment can you start with the fuel adjustments. I don't blame you if you want to stop there and let someone else take over. But if you deliver a nice tight and tuned system (ignition wise), they should be able to bring it in tune fairly quickly for not too much money. That's what you are trying to do here right? Keep on momma's good side?

  6. #6
    Typical of this bboard - tons of efforts to help. I mean that genuinely.

    I've checked all the 'other stuff', had some rpelaced, etc... B2BFast did reset all the linkages, but the car is running VERY rich. I really need the full CMA at htis point. I've already spoken with Gus, went to see him actually. He's pretty German all right. Ya, I don't vork on de engines in de cars, only on de pumps (they dont' make them like him any more, and we'll all be screwed when he's gone). It's about a grand to have him rebuild the pump, and another 4-500 for r&r. There was a great interview on a BMW2002 Club web site (is it blasphemous I'm reading that?) with Gus. He's definitely the MAN.

    On the CMA process, quite frankly the hole things scares me. I've only ever done oil chances and suspension changes before. As for mechanics not familiar with MFI, well that's how I got in this mess. Believe me, its either going to be Dieter at D&M or Al at the Stable (Gus, the guys at EASY, the Gruppemiester all recommended him separately) if I go that route.

    Back to my question though - is there any way to see if the pump needs rebuilt? Mine's complete and all linkages appear to move together, smoothly. I believe the car only had/has ~100K on it as the DMV records show over 10 years where the car wasn't registered.

    Any Bay Area wrenches out there? Anyone? Bueller?
    Chris Purpura @civilizedmisfit
    Member #479
    Current Cars:
    1972 911T aka The "Civilized Misfit" Build
    Miss February - EarlySRegistry 2023 Calendar
    1968 911S Ossi Blau/Beige Corduroy

    Past Cars:
    2019 911 Carrera GTS (sold, no regrets)
    73S - #1100 (restored and now somewhere in Europe)
    1997 993 Carrera 4S Black on Black (sold)

  7. #7

    wish I could help...

    Chris. But, I really dunno nothin about MFI. That, honestly, is why I am a carb only guy.

    I can offer to loan a spare pair of PMO carbs and manifolds, but that won't get you were you need to be. I will ask Frank Beck - Beck's Independent in the Morning. I lost a lot of important info when I moved the computer. PM your phone contact info and I will see if I can set up a Q and A with Frank.

    I am extremely impressed with his knowledge. He has two of my engines in pieces right now. That should indicate my respect.

    Shawn. Or just call me at home 602-795-1311
    67 coupe roller
    99 M96 2.5 litre
    early911s reg 447
    R Gruppe 399

  8. #8
    Senior Member
    Join Date
    Jan 2003
    NW Indiana

    This may not be a practical solution, but do you know anyone that has a working 'S' pump that you could borrow to put on your car. If you can get it run correctly this may help you determine if it needs to be rebuilt.

    R Gruppe #299

  9. #9
    Senior Member WHCJr72S's Avatar
    Join Date
    Oct 2002
    Bay Area
    I would be willing to help you work on your car. I will be out of town in July but I have time in August and I would enjoy it. I have had my 72S for 25 years and have done most of my own work, including working on the MFI.
    Bill Cilker, Jr.
    Gold 72 911S
    31 Ford Model A
    PCA, Early S Registry (#98) & RGruppe (#272)

  10. #10

    Hey Bill!

    Chris, I didn't get a chance to speak with Frank today. I got distracted with flushing the bad Alaska gas out of Barbara's Harley. Took me all the way up to Sedona and back...Tough job. I will try again tomorrow.

    Bill, so nice to meet you in Monterey. Hope to catch you in Ventura in Sept. You meet the nicest people on a Porsche.

    67 coupe roller
    99 M96 2.5 litre
    early911s reg 447
    R Gruppe 399

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