Left bank running way too rich | FerrariChat

Left bank running way too rich

Discussion in 'Boxers/TR/M' started by c4b4the04, Aug 27, 2019.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. c4b4the04

    c4b4the04 Formula Junior
    Silver Subscribed

    Jun 9, 2017
    383
    Northern Virginia
    Full Name:
    Cassidy
    #1 c4b4the04, Aug 27, 2019
    Last edited: Aug 27, 2019
    Hi all,

    New to me 88 Euro-spec TR in June. Did belts and cleaned caps/rotors. New plugs.
    Ran fine for a few hundred miles as I sorted various little things out. Occasionally I would lose 6 cylinders; each time I found some other maintenance item or loose connector and the motor would spring back to full power.

    Started running rich on the left bank on and off. Assumed it was a dying coil and I wasn’t getting spark, hence the smell. Ran resistance tests on each wire, replaced coil lead and replaced coil wit a new one. So I’ve isolated it down to an over-fuel delivery. It’s now constant on 6 cylinders and the smell burns your eyes and nose. Way too much fuel.Timing light verified I have spark at all cylinders but all 6 plugs are fouled with fuel. Passenger bank plugs look like new (because they are!)

    Researching to learn about K-Jetronic systems in our cars. Mine is a no-emissions model so that simplifies it a bit.

    My next step is to look for vacuum line issues. Then maybe look at cold start injector. What after that? Any experiences you can share? Car started doing this after a wash on Saturday (hence chasing my tail assuming spark or electrical related) and I realized it was low on gas (did this halfway to the gas station, I made it home but still low).




    Sent from my iPhone using FerrariChat.com mobile app
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,035
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    My guess would be this is a F113B engine (KE-Jet without Lambda) rather than a F113A (K-Jet without Lambda), but please confirm which engine family that you have -- F113B or F113A? (It's marked on the top of the block at cyl #6).
     
  3. c4b4the04

    c4b4the04 Formula Junior
    Silver Subscribed

    Jun 9, 2017
    383
    Northern Virginia
    Full Name:
    Cassidy
    It is indeed a F113B. That makes it a KE-Jet then? Good to know. Is there a different approach to diagnostic steps then?


    Sent from my iPhone using FerrariChat.com mobile app
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,035
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    "Yes" in some ways, and "no" in others. For KE-Jet, there is a layer of upstream electrics/electronics that is not present on K-Jet, but a lot of the fuel delivery mechanics is similar. For KE-Jet without Lambda, Ferrari wrote Diagnosis Sheet No. 5 to check the various electrical bits -- I don't have a copy of that, but you can download a copy of Diagnosis Sheet No. 6 here that covers the US version F113A040 engine (KE-Jet with Lambda):

    https://www.dropbox.com/s/gm81j3cq3048qe1/TR Diagnosis Sheet N 6 US KE-Jet Injection.pdf?dl=0

    Of course, none of the "Lambda" stuff would apply to your F113B, but there are still a lot of common things (e.g., your thought to rule out the cold start injector on that bank by unplugging it and/or confirming nothing is leaking out the end of it is good). My first suggestion would be to perform Diagnosis Sheet No. 6 Test #2 which you can do in this manner at both of the unplugged Injection ECU connectors using an Ohmmeter without the special 25-pin test box:
    Image Unavailable, Please Login
    Is your TR coming from a situation where it sat unused for a long period(s)? This can be very hard on any of the Bosch CIS injection systems as there are a bunch of very small orifices and tight fitting mechanical parts that can have problems with any debris/varnish/deposits. If Test #2 is OK, the next place I'd go is to confirm/deny if the plunger in fuel distributor on the "rich" bank is stuck and not fully returning to its rest position. Beyond that there's only about 10,000 other things to check ;)
     
  5. Veedub00

    Veedub00 F1 Rookie
    Owner Silver Subscribed

    Jun 30, 2006
    4,886
    Troy, Michigan
    Full Name:
    James
    as always, when screwing around with this stuff, make sure to properly set your idle fuel air mixtures. You could easily have your setup awry.
     
  6. Veedub00

    Veedub00 F1 Rookie
    Owner Silver Subscribed

    Jun 30, 2006
    4,886
    Troy, Michigan
    Full Name:
    James
    it will balance your banks too. the procedure is in the workshop manual. you need vacuum gauges.
     
  7. c4b4the04

    c4b4the04 Formula Junior
    Silver Subscribed

    Jun 9, 2017
    383
    Northern Virginia
    Full Name:
    Cassidy
    Could it have just gotten out of sync that easily? My dad had a 914 with DelOrto’s that would do that but this was running so well Just a day before. I’ve got vacuum gauges and a manometer for synchronizing. I wasn’t going to mess with anything additional until I sorted out this issue but you may well have a point.


    Sent from my iPhone using FerrariChat.com mobile app
     
  8. c4b4the04

    c4b4the04 Formula Junior
    Silver Subscribed

    Jun 9, 2017
    383
    Northern Virginia
    Full Name:
    Cassidy
    It had about 8k miles in the last 15 or so years. Regularly albeit short drives. Not a garage queen and the previous owner was a long time B.B. owner beforehand. He did all his own work. Belonged to Ferrari Club in 1972! What I’m on now just may be from age and old parts, do you think running it until the gas light came on is part of it? That’s not something I regularly do. It does seem to be a thirsty car come to think of it!


    Sent from my iPhone using FerrariChat.com mobile app
     
  9. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,035
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Not the best practice, but don't think that's an issue -- the "reserve" (when the light comes "on") of a TR is ~4 US gallons so it's not like you've run it all the way down to the bitter crud. Additionally, the fuel filters are in the flow path. The trouble with disuse is debris/varnish/deposits forming in the fuel system downstream of the fuel filters.
     
  10. c4b4the04

    c4b4the04 Formula Junior
    Silver Subscribed

    Jun 9, 2017
    383
    Northern Virginia
    Full Name:
    Cassidy
    Ok, so now I’m REALLY confused!

    Tested every vacuum line in the system. Fired it up and it ran like a champ. Got it to the gas station and filled it up. Got on throttle on my way back, did fine until about 4500 and fell on its face. No power. Lifted out, tried again and it was fine. Seemed VERY much like electrical to me.

    So now I’m back to thinking it’s electrical. The times it has run like junk since I have had it were not long after I washed the car. I would check and clean connectors and it would be a few days. Then I’d find some maintenance item and assume I’d cured it. Now I am beginning to think it’s water related. Maybe not at the back.

    Next stop is to look in the front fuse panel area. My plastic rain cowl under the hood is cracked in one area. I repaired the botched up fix from before and I’ll eventually get another. For now I need to focus on running reliably. I’m wondering if I’m not dealing with a power problem getting to that driver side coil/ignition module. Need to take some readings and learn more. Anyone have a quick pic like the one above for testing the ignition module and harnesses? I’m leaning towards harness or relay/fuse panel right now. Fingers crossed I can get on top of this intermittent issue. I’m headed to Watkins Glen in a few weeks to instruct for FCA and would love to trailer the car up for the show. With it running like this so intermittently I don’t dare. Bummer. Would have been her debutant debut


    Sent from my iPhone using FerrariChat.com mobile app
     
  11. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,035
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    You seem to be changing your story ;) If you want to confirm/deny +12V power to run the KE-Jet injection ECUs (Diagnosis Sheet No.6, Test #8), measure the voltage on the red wire at the water thermoswitch relative to ground:

    Image Unavailable, Please Login

    It is rather unlikely that you would lose power to just one of the injection ECUs as they are locally daisy-chained together (the path is +12V from protection relay terminal 87, thru the C12 connector, to the rearmost injection ECU, to the frontmost injection ECU, and then on to a bunch of stuff on the engine including the water thermoswitch). If this +12V power is lost, each bank will run very lean and very weakly and hardly run at all. However, if you have one bank mis-tweaked rich (which you've reported), it could keep running OKish on that bank (when the +12V power is lost), whereas the properly adjusted bank would run poorly/weakly. Unfortunately, being a F113B engine without O2 sensors, you don't have those available to measure for diagnosis.
     
    c4b4the04 likes this.
  12. Veedub00

    Veedub00 F1 Rookie
    Owner Silver Subscribed

    Jun 30, 2006
    4,886
    Troy, Michigan
    Full Name:
    James
    those two connectors going to the right rear trapezoidal box could be loose. pull the round plugs and look for pins that could be causing intermittant faults.
     
  13. c4b4the04

    c4b4the04 Formula Junior
    Silver Subscribed

    Jun 9, 2017
    383
    Northern Virginia
    Full Name:
    Cassidy
    What trapezoidal box? Is this under the fender passenger side, sort of near the coil?


    Sent from my iPhone using FerrariChat.com mobile app
     
  14. c4b4the04

    c4b4the04 Formula Junior
    Silver Subscribed

    Jun 9, 2017
    383
    Northern Virginia
    Full Name:
    Cassidy
    This is just the sort of thing I’m searching. Real-world experience and where to check. Thank you. Steep learning curve on this one. I’ll get it and contribute but now I’m just grateful for the advice.

    And yes, my story is changing it’s frustrating to discover where I’m having issues. Long time since I’ve worked on a car without data port info!


    Sent from my iPhone using FerrariChat.com mobile app
     
  15. Veedub00

    Veedub00 F1 Rookie
    Owner Silver Subscribed

    Jun 30, 2006
    4,886
    Troy, Michigan
    Full Name:
    James
    yea, the protection relay and barometric sensors are in there.
     
  16. JohnMH

    JohnMH Formula 3

    Jan 28, 2004
    1,625
    Dubai / Bologna
    Ok, don’t change any settings! My 91 had the exact same issue. One bank rich off the scale. Just unplug wires from the cold start injectors and recheck. Not certain how, but my right one was stuck on. Left not. Car passed emissions easily after unplugging the right wire.

    I live in a hot climate, so leaving them unplugged is an option. Until I get bored one weekend and need to figure the problem out.
     

Share This Page