No Spark

Discussion in 'Technical' started by riporter, Dec 31, 2003.

  1. riporter

    riporter Member

    Joined:
    Oct 4, 2003
    Messages:
    2,474
    Likes Received:
    4
    Trophy Points:
    0
    Location:
    Charleston S.C.
    Vehicle:
    70 Maverick 2 dr. modified street cruiser, 72 Comet tube chassis drag car
    I'm attempting to get the 72 Comet fired off... I've got good gas to the carb but no spark at the plugs...with the ignition switch in the on position Im getttin 5 volts to the coil...in the cranking position I get 12 volts at the coil.
    I only get 12 volts out of the coil to the distributor...is that right?
    I've tried 2 different coils and 2 different distributor caps.
    The rotor is turning.. the points are making and breaking as the rotor turns (this is not an electronic ignition setup, points and condenser)
    I've checked and double checked the obvious, plugs,wires and soforth.
    Any ideas would be greatly appreciated,
    Thx Rick
     
    riporter, Dec 31, 2003
    #1
  2. wmabear54

    wmabear54 Member

    Joined:
    Nov 22, 2003
    Messages:
    34
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    bedford, va
    Vehicle:
    1974 Comet GT, 1977 VW Bus, 1969 Chev C-20, 1962 Century wooden boat 318 cid, 1923 Model T
    The 5 volts seems to low, 12 volts on cranking should not happen I don't think, should it. As far as anything else check or replace the condenser. Good luck!
    Mike
     
    wmabear54, Dec 31, 2003
    #2
  3. wmabear54

    wmabear54 Member

    Joined:
    Nov 22, 2003
    Messages:
    34
    Likes Received:
    0
    Trophy Points:
    0
    Location:
    bedford, va
    Vehicle:
    1974 Comet GT, 1977 VW Bus, 1969 Chev C-20, 1962 Century wooden boat 318 cid, 1923 Model T
    Are you getting the big spark to the top of the distributor from the top of the coil.
    Mike
     
    wmabear54, Dec 31, 2003
    #3
  4. Mavaholic

    Mavaholic Growing older but not up!

    Joined:
    Mar 9, 2002
    Messages:
    14,993
    Likes Received:
    212
    Trophy Points:
    258
    Location:
    Live Oak, FL
    Vehicle:
    Original 72 Sprint Owner, 71 Comet GT, 57 Ranchwagon, 57 4 dr Wagon
    DOOOOOOOO!!! forgot the rotor. Just kidding. What did you set the points with? A dwell meter is most desirable. If you can get your hands on one, set them at 28-32 degrees while cranking. Dwell affects timing so set it as accurately as possible. Also file the points. They can get a film on them and wont conduct. The condenser can also be bad so you wont get any spark. As cheap as they are, I'd go get a new set of points and condenser. 12v while cranking should fire it up. Personally, If you got about $90 you can spend, go get a Petronix set up and deep six the points & condenser crap.
     
    Mavaholic, Dec 31, 2003
    #4
  5. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    26,590
    Likes Received:
    2,936
    Trophy Points:
    978
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    dennis, it sounds like you have covered it well...frank...:bananaman :bananaman
     
    71gold, Dec 31, 2003
    #5
  6. riporter

    riporter Member

    Joined:
    Oct 4, 2003
    Messages:
    2,474
    Likes Received:
    4
    Trophy Points:
    0
    Location:
    Charleston S.C.
    Vehicle:
    70 Maverick 2 dr. modified street cruiser, 72 Comet tube chassis drag car
    Ok...I changed the condenser and filed the points... I havn't set the gap on the points but I know they close and open properly.
    Still no spark...I also checked for a spark from the coil wire to the distributor...nothing.
    I even pulled the coil off the Mav just to make sure.
    The condensor wire runs from the points back out to the negative side of the coil...only thing I know to do is check continuity on that wiring.
    I'm stumped:confused:
     
    riporter, Dec 31, 2003
    #6
  7. Mavaholic

    Mavaholic Growing older but not up!

    Joined:
    Mar 9, 2002
    Messages:
    14,993
    Likes Received:
    212
    Trophy Points:
    258
    Location:
    Live Oak, FL
    Vehicle:
    Original 72 Sprint Owner, 71 Comet GT, 57 Ranchwagon, 57 4 dr Wagon
    With the ignition switch in the run position there should be 12v sitting on the + side of the coil. The - side should be connected to the points along with the condenser wire. With the points open, there should be 12v (or close) sitting on the points terminal. At this time the capacitor is charging. Also, there needs to be a ground wire from the plate that the points & condensor bolt to, and the other end hooked to the distributor housing. No ground, no fire.Check to see If everything is cool at this point. If so, gap the open at .015 and crank. when the points close, the cap discharges back through the coil which is nothing more than a step up transformer. so if still no spark, the coil is probably bad.
     
    Mavaholic, Dec 31, 2003
    #7
  8. Dan Starnes

    Dan Starnes Original owner

    Joined:
    Mar 10, 2002
    Messages:
    5,235
    Likes Received:
    52
    Trophy Points:
    146
    Location:
    West Central IL
    Vehicle:
    Stallion, 72 Grabber, Sprint, 77 4dr Maverick
    You know if he doesnt get it running tonite, I wont be able to sleep. This one of those cliffhanger posts that I cant wait to find out what the culprit was.
    Dan
     
    Dan Starnes, Dec 31, 2003
    #8
  9. Mavaholic

    Mavaholic Growing older but not up!

    Joined:
    Mar 9, 2002
    Messages:
    14,993
    Likes Received:
    212
    Trophy Points:
    258
    Location:
    Live Oak, FL
    Vehicle:
    Original 72 Sprint Owner, 71 Comet GT, 57 Ranchwagon, 57 4 dr Wagon
    I know the feeling. He's probably either out working on it or else found that a big hammer and cinder blocks help alleviate some of that built up frustration.
     
    Mavaholic, Dec 31, 2003
    #9
  10. 71gold

    71gold Frank Cooper Supporting Member

    Joined:
    Apr 9, 2002
    Messages:
    26,590
    Likes Received:
    2,936
    Trophy Points:
    978
    Garage:
    1
    Location:
    MACON,GA.
    Vehicle:
    '73 Grabber
    :rolleyes: :rolleyes: rick, maybe we should move the mini meet up to your place and see if we can get this sucker fired up:D :D ...frank...:bananaman :bananaman
     
    71gold, Dec 31, 2003
    #10
  11. riporter

    riporter Member

    Joined:
    Oct 4, 2003
    Messages:
    2,474
    Likes Received:
    4
    Trophy Points:
    0
    Location:
    Charleston S.C.
    Vehicle:
    70 Maverick 2 dr. modified street cruiser, 72 Comet tube chassis drag car
    HeHe...yall were right...I had to go back to the shop and give it one more try...good thing to...I found the problem, the ignition wire to the coil had a break in it inside the wiring harness...with it disconnected I had 12 volts on the money...soon as I hooked it up and it went under load voltage dropped to 6 volts...turns out only 2 strands of wire were good in the jacket.

    Thx for the help Dennis...and thank goodness for a Fluke meter.

    She fired right up and is purrin like a kitten...sounds prety good for not havin been run in 2 years...gonna take her for a spin in the A.M. see how she shifts out:clap: :bananaman :clap:
     
    riporter, Dec 31, 2003
    #11

Share This Page