News

Stalling 328 when slowing down and it's not the clutch...

Discussion in 'Technical Q&A' started by rob lay, Dec 8, 2003.

  1. rob lay

    rob lay Administrator
    Staff Member Admin Owner Miami 2018

    Dec 1, 2000
    49,024
    Southlake, TX
    Full Name:
    Rob Lay
    I don't really need tech advice, but thought I would document it here as Norwoods is taking care of it for me. I was out of town, but Jennie picked the 328 up from Norwoods so she could go out on the town while I was gone Saturday. (I found her panties in the 328 this morning, but that's another story). :D She called me Saturday night and said that after the car warmed up that it would stall when slowing down or coming to a stop light. Since they just replaced the clutch cable, I thought maybe the clutch wasn't disengaging. I told her just to put in neutral when she was slowing down.

    Well anyway, this morning as I was driving it to Norwoods it did the same thing to me as I would slow down or come to a stop. Putting it in neutral didn't help anything.

    I know what it is now, but anyone else want to make some guesses for fun?

    Here's the info...

    1) Stalls when slowing down or coming to a stop.
    2) Putting in neutral it will still stall.
    3) It doesn't stall when the car is cold (fast idle).

    I have one more hint, but I'll wait a little... :)
     
  2. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,558
    USA
    Full Name:
    Hugh G. Rection
    I need a hint...does it idle at the normal speed when warm? (around 900 to 1000 rpms?)
     
  3. TOM B

    TOM B Formula 3

    Jul 24, 2003
    1,038
    Orange County, NY
    Full Name:
    Thomas Buckley
    Rob,
    The idle is set too low ?

    If i'm right-----do I win a prize ? :)
     
  4. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,558
    USA
    Full Name:
    Hugh G. Rection
    I'm thinking it is not that simple, as Rob would know to turn the big knob to adjust the idle back up....hmmmmmm
     
  5. TCM

    TCM Formula Junior

    Nov 10, 2003
    552
    Tyngsborough, MA
    Does the idle flucuate at all when in neutral after being warmed up (when it does not stall that is)?
     
  6. snj5

    snj5 F1 World Champ

    Feb 22, 2003
    10,213
    San Antonio
    Full Name:
    Russ Turner
    mondialesque (electrical) answers:
    1.bad battery secondary to and concommitant with a bad altenator/voltage regulator.

    2.Bad Kjet protection relay or blown fuse

    More wags later
     
  7. kdross

    kdross Formula Junior
    Silver Subscribed

    Feb 10, 2002
    872
    NJ
    Full Name:
    Ken
    I had the same problem with my Alfa Spider last month. The problem was that I forgot to replug the Bosch FI plug into the computer when I unplugged it to install a new air filter (the system on the Alfa is mounted on top of the air filter housing.

    Ken
     
  8. 308GTS

    308GTS Formula 3

    Dec 27, 2001
    2,220
    TN
    It could be a few items. A disconnected vacuum line or large vacuum leak. Aux. Air Valve could be stuck or it could be the fuel pump. There are other things it could be but these are the main culprits.
     
  9. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    18,159
    Texas
    Full Name:
    Steve Magnusson
    Rob -- Is this really a specific "Gizmo X failed" issue, or something more "entertaining" -- like a squirrel stuck in the air inlet? Give us the second clue...
     
  10. CraigFL

    CraigFL Formula Junior

    Jan 17, 2001
    954
    Panama City, FL
    Full Name:
    Craig
    When mine does that, I know it's time to clean out the throttle body around the throttle plate. Dirt/crud builds up causing the idle speed to drop below minimum before settling to normal. sometimes this dip caused mine to almost die.

    P.S. When mine did this there were no panties involved....
     
  11. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,558
    USA
    Full Name:
    Hugh G. Rection
    308GTS I would disagree on the aux air valve being a possible source of the problem. He implies that cold idle works (means the valve opens okay). As the car warms up, the valve closes, which is normal. If it was stuck open, he would have a constantly fast idle. If it where stuck close, he would have no fast (cold) idle and would always be at the warm idle setting of around 1000 rpm. That would not cause the car to stall, except possibly when cold, but he specifically said it does not stall when cold (fast idle).

    I think your first thought, of a possible vacuum leak is more likely.
     
  12. TCM

    TCM Formula Junior

    Nov 10, 2003
    552
    Tyngsborough, MA
    I am guessing a vacuum leak as well. Under demand, the engine can compensate for the leak but at idle it can't causing a rough idle and stall. But the fact that Rob neve rmentioned a rough idle is what is confusing me.
     
  13. rob lay

    rob lay Administrator
    Staff Member Admin Owner Miami 2018

    Dec 1, 2000
    49,024
    Southlake, TX
    Full Name:
    Rob Lay
    I'll get the exact information from Norwoods to explain it technically. The next hint is they had made adjustments before the problem started so I could pass emissions. I'll find out exactly why technically, but the laymans explanation is that when the RPM's drop like slowing in traffic or stopping that the momentum takes it past idle until 0. A little trick to pass emissions, but not good for everyday driving.
     
  14. snj5

    snj5 F1 World Champ

    Feb 22, 2003
    10,213
    San Antonio
    Full Name:
    Russ Turner
    Hey!
    You didn't tell us it was a deliberately induced fault!
    It's way lean as the airmass plate inertia returns to rest at idle it keeps on moving downward and shuts off enough gas to keep it idling. They set the plate position stop very lean (low). Very clever if that's it.
    Great quiz! We need more of these.
     
  15. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,558
    USA
    Full Name:
    Hugh G. Rection
    Okay, so now I am (still guessing) that they just set the CO too lean.
     
  16. Steve Magnusson

    Steve Magnusson F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    18,159
    Texas
    Full Name:
    Steve Magnusson
    ...and left the O2 sensor unplugged?
     
  17. 308GTS

    308GTS Formula 3

    Dec 27, 2001
    2,220
    TN
    I see what you are saying but that doesn't make the car go into fast idle. I can jumper my temp sensor and start up the 308 and it will idle right at 1000 and the WUR, AAV, etc. will still function. So if the valve stayed open during normal running the car would be under a lean condition which could cause the car to stall but not under acceleration.
     
  18. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,558
    USA
    Full Name:
    Hugh G. Rection
    308GTS, the aux air valve, if stuck open, shouldn't cause a lean condition. It is drawing the air from the air intake, after the air flow sensor, so if stuck open, the air flow sensor would adjust the fuel and keep the mixture from leaning out.

    BTW, I am NOT a mechanic, but have tinkered on them over the years, and replaced a couple aux air valves in the past. This is where I have gotten some great info. on how the system works
    http://www.auto-solve.com/mech_inj.htm
     
  19. snj5

    snj5 F1 World Champ

    Feb 22, 2003
    10,213
    San Antonio
    Full Name:
    Russ Turner
    I also do not think it is the air valve as Dave said. A vacuum leak just big enough to matter at low rpm would make it lean out then overcome by running airflow. I don't think the emissions adjustment mentioned by Rob would affect the aux air valve, but I could be wrong.
    I'm still thinking that the airmass sensor plate is coming too far to a close from an 'emissions adjustment' by Norwood as Rob indicated. Remember when the airmass sensor plate comes down to a close the fuel stops, which also explains the inertial behavior as the plate swings down to a close if the stop is maladjusted..

    What do you guys think?
     
  20. jimpo1

    jimpo1 Two Time F1 World Champ
    Silver Subscribed Owner

    Jul 30, 2001
    21,738
    Dallas, TX
    Full Name:
    Jim E
    I also think we need a full accounting of why you found her panties in the car? :D
     
  21. Darolls

    Darolls F1 Veteran
    BANNED

    Jul 2, 2003
    6,799
    Full Name:
    Sparky
    My guess; the a/f mixture is off.

    Now, tell us about the 'panties' episode!
     
  22. DGS

    DGS Three Time F1 World Champ
    Rossa Subscribed

    May 27, 2003
    33,566
    MidTN
    Full Name:
    DGS
    1) intake valve adjustments "tweaked" (longer opening)

    2) vacuum advance disconnected

    3) vac leak

    4) ... well, if the cold injector was leaking, you wouldn't have passed emissions.
     
  23. davequick

    davequick Formula Junior

    May 27, 2003
    307
    Bellevue, WA
    Full Name:
    Dave Quick
    Try this:

    1) turn off every electrical thing in the car (i.e. AC/radio/heater/lights/etc.)
    2) disconnect battery, also diconnect the grounding strap up in front next to the driver side headlight against the frame.
    3) wait 10+ minutes
    4) connect grounding strap, connect battery
    5) start car and let it idle (only blip the throttle once to get the alternator to engage) 10 minutes
    6) turn on EVERYTHING elecrical in the car, wait 10 minutes

    You've just reset the k-jettronic.

    Try it and see if it works. It's worth investing a half hour.

    -dq
     
  24. DGS

    DGS Three Time F1 World Champ
    Rossa Subscribed

    May 27, 2003
    33,566
    MidTN
    Full Name:
    DGS
    (Bump)

    So what was the answer?
     
  25. snj5

    snj5 F1 World Champ

    Feb 22, 2003
    10,213
    San Antonio
    Full Name:
    Russ Turner
    Rob - we're waiting for the answer here.
    Don't make me call Norwood.
    :)
     

Share This Page