FRAMING JOHN DELOREAN - ON VOD www.framingjohndeloreanfilm.com
Page 3 of 5 FirstFirst 1 2 3 4 5 LastLast
Results 21 to 30 of 45

Thread: Chugging, hard start, dies on acceleration... you tell me.

  1. #21
    'Merican Spatula
    Join Date:  Jun 2014

    Location:  Bothell, WA

    Posts:    26

    My VIN:    1242

    Quote Originally Posted by NightFlyer View Post
    When vacuum should be present at the CPR/WUR: only after a cold start up, and only for the first few minutes of running (until the engine coolant temp reaches 104F).

    When vacuum should be present at the electrical distributor's solenoid: only when the engine coolant temp has reached 104F or higher.

    When vacuum should be present at the electrical distributor's vacuum chamber: only when the engine temp has reached 104F or higher AND during open throttle events (both condition must be met - if only one is met, then there shouldn't be vacuum here). There should NEVER be vacuum here at idle ever (idle micro-switch engaged/closed).
    Despite having read your post at least eight times, I still misread it. I have no vacuum at the distributor advance when cold, but when hot, there is constant vacuum at the distributor advance chamber - at idle and under load. Was unable to confirm vacuum at the CPR / WUR at this time - I think the engine was already warmed up.

    Side note: the frequency valve is buzzing away, I believe, as it should. Probably no need to mess with it as I believe my findings were coincidental.

  2. #22
    Senior Member Bitsyncmaster's Avatar
    Join Date:  May 2011

    Location:  Leonardtown, MD

    Posts:    9,008

    My VIN:    03572

    Quote Originally Posted by LoveThySpatula View Post
    there is constant vacuum at the distributor advance chamber - at idle and under load.
    There should not be vacuum at idle. Most likely your solenoid connector has fallen off or the idle switch is not working (miss adjusted or broken).
    Dave M vin 03572
    http://dm-eng.weebly.com/

  3. #23
    Banned
    Join Date:  Sep 2011

    Location:  Sunfield, Michigan, USA

    Posts:    2,444

    My VIN:    1798

    Quote Originally Posted by LoveThySpatula View Post
    I have no vacuum at the distributor advance when cold, but when hot, there is constant vacuum at the distributor advance chamber - at idle and under load.
    Well, then, that's not right, as there should only ever be vacuum at the distributor advance chamber when the engine is warm (104F+) AND during open throttle events (both conditions must be simultaneously present, otherwise there shouldn't be vacuum present at such location - and NEVER at idle), so let's tackle this problem first.

    First, make sure that the idle micro-switch is in fact engaging (closing) at idle. If not, then you'll need to clean and lubricate the striker bracket arm (and possibly the throttle spool/cable/linkages, as may be required if there's something that's preventing the arm from freely fully pivoting), and adjust the striker screw as is necessary.



    Next, use a multi-meter to test the idle micro-switch - resistance when engaged (closed) should be approaching 0 ohms, and when open should be approaching infinity ohms. If you get readings other than these, then the switch is bad and will need to be replaced.

    If the idle micro-switch checks out OK, then you'll want to use your multi-meter to confirm power into the switch. If that checks out, then you'll want to turn your attention to the vacuum solenoid.



    Note that in the reference photo above, the power wire and vacuum hoses are not attached to the vacuum solenoid.

    Again, use your multi-meter to confirm power at the solenoid when the idle micro-switch is engaged (closed). If you're not reading any power to the solenoid, then check the wire for a break/defect/short to ground/etc.

    If power to the solenoid was always good when the idle micro-switch is engaged, then you know that you have a failed vacuum solenoid, and it will need to be replaced.

    If any of that doesn't make sense or if you're not following with the way I've laid it out, don't be afraid to ask additional questions.

    Best luck
    Last edited by NightFlyer; 08-27-2014 at 04:42 PM.

  4. #24
    DMC Midwest - 815.459.6439 DMCMW Dave's Avatar
    Join Date:  May 2011

    Location:  Taylors SC

    Posts:    5,326

    My VIN:    (former)05429

    Club(s):   (DMWC) (DCUK)

    Quote Originally Posted by NightFlyer View Post



    :
    Current events test. Why do you have rubber bullets all over your fuel distributor?
    Dave S
    DMC Midwest - retired but helping
    Greenville SC

  5. #25
    Banned
    Join Date:  Sep 2011

    Location:  Sunfield, Michigan, USA

    Posts:    2,444

    My VIN:    1798

    Quote Originally Posted by DMCMW Dave View Post
    Current events test. Why do you have rubber bullets all over your fuel distributor?
    It's a picture from the web - not of my car

  6. #26
    Senior Member
    Join Date:  May 2011

    Location:  Northern NJ

    Posts:    8,583

    My VIN:    10757 1st place Concourse 1998

    Quote Originally Posted by NightFlyer View Post
    It's a picture from the web - not of my car
    Also be aware it matters which port the hoses go to. If you mix them up things won't work right. You should be able to hear the valve click when voltage is applied.
    David Teitelbaum

  7. #27
    Senior Member Flash66's Avatar
    Join Date:  May 2014

    Posts:    261

    My VIN:    16811

    Just to add. I hate the electrical connector that was used for this solenoid! I knock it off every time I have my hand back there. Thinking of soldering a better connector to the terminals mating a matching plug that snaps together.

  8. #28
    Senior Member Bitsyncmaster's Avatar
    Join Date:  May 2011

    Location:  Leonardtown, MD

    Posts:    9,008

    My VIN:    03572

    Quote Originally Posted by Flash66 View Post
    Just to add. I hate the electrical connector that was used for this solenoid! I knock it off every time I have my hand back there. Thinking of soldering a better connector to the terminals mating a matching plug that snaps together.
    +1
    Been there, done that.
    Dave M vin 03572
    http://dm-eng.weebly.com/

  9. #29
    Banned
    Join Date:  Sep 2011

    Location:  Sunfield, Michigan, USA

    Posts:    2,444

    My VIN:    1798

    Quote Originally Posted by David T View Post
    Also be aware it matters which port the hoses go to. If you mix them up things won't work right.
    I've not confirmed this myself, but I've read a few posts that imply/infer that some of the aftermarket vacuum solenoids on the market have the opposite hose arrangement vs the arrangement found on the stock/OEM vacuum solenoid.

    So, yes, when ever trouble shooting the vacuum solenoid, confirm that the vacuum hoses are in fact properly connected to it.

  10. #30
    'Merican Spatula
    Join Date:  Jun 2014

    Location:  Bothell, WA

    Posts:    26

    My VIN:    1242

    Well gents, sometimes is the simple things in life that drive you crazy.

    After hearing you guys discuss the vacuum solenoid and hearing about how easily the connector falls off - something clicked in my rusty old brain. I believe it was NightFlyer (again) that posted that picture of the solenoid (and fuel distributor adorned with rubber bullets) saying that the hoses and the power were disconnected.

    I took a look this morning and confirmed my suspicions.

    The power wasn't hooked up to the solenoid. And I don't think is has been since I did the tune up.
    Go figure.

    I drove her around a bit today and she runs, I would say, 90% better... there is still that lack of acceleration at wide open throttle - not that I'm driving it like a punk kid in a civic - but trying to go up steep hills still results in having to back off the gas just a tad bit to keep accelerating... I'm going to take a risk and drive her to work today, I'll let you guys know what, if anything, happens.

    EDIT: Also thanks for everyone's help in trying to figure this out, you guys have been a great help so far.
    Last edited by LoveThySpatula; 08-29-2014 at 03:00 PM.

Page 3 of 5 FirstFirst 1 2 3 4 5 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •