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Thread: Installed valve height

  1. #21
    Join Date
    Mar 2018
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    37

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    Update: Got everything back together and reinstalled. I'm now trying to get my CIS dialed in and it's a learning curve because I've never owned or worked on a K-jet equipped car. The 308/328 WSM doesn't have much info but I have a copy of the 1983 Mondial QV WSM and it has a pretty good section on the fuel injection that I'm assuming is identical. So I've been using those charts and pressures for my troubleshooting. The engine fires right up but has a really rough idle. The auxiliary air and cold idle and electro-valves seem to be working, it will idle a bit over 2000 until the yellow light on the instrument cluster goes out at which point I can see the high idle control valve close and it drops to about 1200 - still really rough though. If I press on the air metering plate very slightly with my finger it idles perfect so I was convinced I just had an intake leak but I can't find any. I've used starting fluid and a smoke generator to try find one but no indications. I don't want to mess with the mixture adjustment until I have exhausted all other possibilities. It ran perfect when I took it apart and I didn't really mess with anything but the injectors did sit in a box for a year so they might be suspects.

    Anyway if any CIS gurus have tips or advice I'm all ears. I put the car on non-op status with the DMV last year and I really can't operate it until after August 5th without having to pay the entire 2018-2019 license fee so I've got a few weeks to get this sorted out. I have driven it around the block a few times, it runs good but the idle seems to be way too lean. The plugs are chalky white.

  2. #22
    Join Date
    Sep 2009
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    In the big house
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    7,134

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    Quote Originally Posted by kcabpilot View Post
    Update: Got everything back together and reinstalled. I'm now trying to get my CIS dialed in and it's a learning curve because I've never owned or worked on a K-jet equipped car. The 308/328 WSM doesn't have much info but I have a copy of the 1983 Mondial QV WSM and it has a pretty good section on the fuel injection that I'm assuming is identical. So I've been using those charts and pressures for my troubleshooting. The engine fires right up but has a really rough idle. The auxiliary air and cold idle and electro-valves seem to be working, it will idle a bit over 2000 until the yellow light on the instrument cluster goes out at which point I can see the high idle control valve close and it drops to about 1200 - still really rough though. If I press on the air metering plate very slightly with my finger it idles perfect so I was convinced I just had an intake leak but I can't find any. I've used starting fluid and a smoke generator to try find one but no indications. I don't want to mess with the mixture adjustment until I have exhausted all other possibilities. It ran perfect when I took it apart and I didn't really mess with anything but the injectors did sit in a box for a year so they might be suspects.

    Anyway if any CIS gurus have tips or advice I'm all ears. I put the car on non-op status with the DMV last year and I really can't operate it until after August 5th without having to pay the entire 2018-2019 license fee so I've got a few weeks to get this sorted out. I have driven it around the block a few times, it runs good but the idle seems to be way too lean. The plugs are chalky white.
    So, the variable is the new injectors....
    Pressing on the sensor plate enriches the mixture
    White plugs-Check

    Running cold and running hot require different pressure from the WUR. If those pressures are in specs AND the sensor plate height is correct (see WSM), adjust the mixture. O2 sensor if equipped, disconnected. Righty ->rich Lefty->lean. Turn the mixture screw 1/8 turn and wait for the engine to respond. Remember that you need to plug the hole (for the mixture screw) whilst your evaluating the effects of your adjustments. Go slow, as a little goes a long ways.
    Sarasota Italian Garage, LLC
    "The Fluent in Ferrari Guys" celebrating 37 years of service excellence
    Lakewood Ranch, FL
    www.fluentinferrari.com

  3. #23
    Join Date
    Mar 2018
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    37

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    To clarify - they are not new injectors, they are the same ones I took out. They're brass so not sure if they are the original ones or if they were replaced at some time in the past. Anyway I took them all out yesterday and stuck them into 8 empty water bottles which happen to fit perfectly onto the threaded mounting bosses. I did a quick visual of the spray patterns and they seem to be pretty even but I couldn't do an actual measured flow test or open them up full pressure because they fit so well I'll need to poke or drill some vent holes. But that is why I've been reluctant to mess with the mixture adjustment since all of the components are the same and it ran fine before I took it apart. I did however replace all of the polymide fuel lines.

    So I think today I'll go ahead and make those vent holes and do a more thorough test throughout the entire range as well as recheck the cold and warm pressures on the WUR with and without vacuum because thinking back I forgot to bleed the air out of my gauge line the first time I did it. If everything checks out I'll put it all back together and try adjusting the mixture.

    One other thing I wasn't sure about is the idle air bypass needle valve. I didn't find anything in the WSM but read somewhere to start with it 4 turns out from fully closed and the throttle stop screw a half turn past where it just catches a sheet of paper between it and the arm lever. So that's where they are right now.

    I'll snap a couple of photos today and come back with a report. Thanks for the tips.

  4. #24
    Join Date
    Mar 2018
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    37

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    Update: After extensive tests and observations I'm pretty sure my injectors are the problem. Two of them don't do anything but dribble until I have pressed the plate down about a half inch and at least three of them continue to drip after shut off. My warm pressures at the WUR are 2.5 without vacuum and and 3.3 with vacuum which are at the low end but within spec. My cold pressure looks to be okay as well even though I don't have a thermometer to tell me exactly what temperature it is in the garage (I'm guessing it's about 75 deg) Watching the injectors throughout the range, I can see why my idle was so bad. I could try make up a pressure pump to clean them but I got a pretty good deal on a whole set of new ones on Amazon ($163)
    Attached Images Attached Images

  5. #25
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    Jun 2007
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    Massachusetts
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    Love the water bottles!! Pretty clever way to observe the individual injectors. Sounds to me like a replacement set of injectors is a good idea. I'm sure you have seen my tutorial on cleaning them. Super easy to clean if you acquire the apparatus.
    Birdman308 for parts and tutorials!

  6. #26
    Join Date
    Mar 2018
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    37

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    Yes, I have read pretty much all of your tutorials and also watched a number of YouTube videos done by Mercedessource on cleaning injectors. I started building my own contraption by modifying a bottle jack from Harbor Freight but got stalled trying to find a barb and swivel nut to connect to the injector itself. I’ll probably finish it and see if I can recon my old injectors as spares. For now, while I wait for my new ones I think I’ll switch these ones around and redo my test to make sure the problem is not from the fuel distributor but I’m pretty sure it’s the injectors. There is actually a lot of info on the CIS injection system out there once you start looking.

  7. #27
    Join Date
    Jun 2007
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    War-Chester - the dark side of the MOON, apparently...
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    2,782

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    Quote Originally Posted by Birdman View Post
    Love the water bottles!! Pretty clever way to observe the individual injectors. Sounds to me like a replacement set of injectors is a good idea. I'm sure you have seen my tutorial on cleaning them. Super easy to clean if you acquire the apparatus.
    That is an INGENIUS way to test the ENTIRE FUEL INJECTION SYSTEM, soup-to-nuts, fully assembled and running. Wish 'we' had thought of this when I had David replace my injectors last year.....

  8. #28
    Join Date
    Jun 2007
    Location
    Florida, USA
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    2,602

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    Glad you got her sorted. When i had ??? rebuild the K-Jet and install new filter/etc had a problem similar as yours. Realized i didn't have the rebuilt k-Jet seated properly. After remounting she works fine, then came using Colortune to get A/F ratio set. Think Verell has my old Colortune (if that helps).
    Enjoy the Drive,
    Steven
    2014 435i M-Opt, M LSD, Dinan CAI/IC/BTurbo/Stage 4, ER TIC/CP, GFB DV+, Fabspeed HJS cat DP & Mich PS4S.

  9. #29
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    Jun 2007
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    Hudson, MA
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    8,892

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    Quote Originally Posted by Wingman View Post
    Think Verell has my old Colortune (if that helps).
    Hmm, I think I might have ended up with that. It would explain where this extra Colortune came from.
    I enjoy talking to you. Your mind appeals to me. It resembles my own mind except that you happen to be insane.
    ― George Orwell, 1984

  10. #30
    Join Date
    Mar 2018
    Posts
    37

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    A friend gave me a Heathkit CI-1080 Exhaust Gas Analyzer. It’s a pretty crude device but I’ll see how it works.

    https://images.app.goo.gl/sYy5vNxvQ994X2hz8
    Last edited by kcabpilot; 07-25-2019 at 07:08 PM.

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