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302/5.0 Tech Help?

Discussion in 'The Hokey Ass Message Board' started by Kustom.Falcon, Mar 12, 2011.

  1. Kustom.Falcon
    Joined: Nov 1, 2010
    Posts: 502

    Kustom.Falcon
    Member

    Anything's appreciated here:

    I've got a seasoned '87-'93 5.0 that starts up great, idles well, but after running it around the block a few times, begins to sound like an old-time tractor... kind of "putting," if you will.

    Give it some time to cool down, start it up again, and it's fine. Run it around the block and we're back to the tractor effect.

    Any ideas?

    *I just replaced the dist. cap, rotor, plugs, and wires. It uses a PerTronix ignition module. Vacuum may not be absolutely optimal due to some old, bad lines. It did this before I did the plugs, wires, cap, and rotor.
     
  2. daddio211
    Joined: Aug 26, 2008
    Posts: 6,002

    daddio211
    Member

    Are you getting enough fuel pressure? Install a gauge (even a temporary one) where you can see it while driving.
     
  3. Malcolm
    Joined: Feb 9, 2006
    Posts: 7,725

    Malcolm
    ALLIANCE MEMBER
    from Nebraska

    Do you have a ballast resistor installed for your ignition? I had similar problems in my Galaxie when I changed to Ford Duraspark ignition. There was actually a factory ballast resistor wire in the dash and I had another ballast resistor inline near the engine. Too much voltage drop caused the car to run like crap. Removed the ballast resistor and it ran like a top!



    Malcolm
     
  4. Kustom.Falcon
    Joined: Nov 1, 2010
    Posts: 502

    Kustom.Falcon
    Member

    daddio211: I'll see what I can do.
    Malcolm: Good question - I'll have to check the dash.
     

  5. Kustom.Falcon
    Joined: Nov 1, 2010
    Posts: 502

    Kustom.Falcon
    Member

  6. 61falcon
    Joined: Jan 1, 2009
    Posts: 772

    61falcon
    Member

    valve hanging open. if an exhaust valve sticks open, it will make a putting sound from the exhaust.
     
  7. Francisco Plumbero
    Joined: May 6, 2010
    Posts: 2,531

    Francisco Plumbero
    Member
    from il.

    Pull and check your plugs? Gap good? Did you do the wires correctly? Make proper contact? Leave a vac line off? Sounds like support and not mechanical, odd that it runs OK then runs like crap.
     
  8. dannyego
    Joined: Mar 12, 2008
    Posts: 1,387

    dannyego
    Member

    fuel line to close to the header or something cause gass to heat up and Vapor lock?? where is your temp at when it starts having issues?
     
  9. Ole don
    Joined: Dec 16, 2005
    Posts: 2,915

    Ole don
    Member

    Time for a compression check. You may have a valve seat or guide problem. This test will tell you where.
     
  10. Kustom.Falcon
    Joined: Nov 1, 2010
    Posts: 502

    Kustom.Falcon
    Member

    Good plans - I'll run them all down.

    Thanks!
     
  11. rustyford40
    Joined: Nov 20, 2007
    Posts: 2,168

    rustyford40
    Member
    from Mass Bay

    The timing for a 5L HO is not the same as a 302
     
  12. check the coil.
     
  13. Shizzelbamsnapper
    Joined: May 13, 2010
    Posts: 317

    Shizzelbamsnapper
    Member
    from Ohio

    I'm going to assume this isn't in a Mustang or anything new. Check to make sure you have a vented gas cap or that the tank vent isn't plugged. It will act just like a vapor locked fuel line. Just a thought.
     
  14. daddio211
    Joined: Aug 26, 2008
    Posts: 6,002

    daddio211
    Member

    That's a great point.
     
  15. pimpin paint
    Joined: May 31, 2005
    Posts: 4,937

    pimpin paint
    Member
    from so cal

    Hey,

    Does your 5.0 still run the EFI? '85-92 Mustang HO motors were all EFI originally. Are you runnin the computer and oem wires to the cold start sensors? HO motors distributors run counterclock wise to 260,289 & non HO 302 engines.
     
  16. Kustom.Falcon
    Joined: Nov 1, 2010
    Posts: 502

    Kustom.Falcon
    Member

    It was a long block install. Simple, old school, naturally aspirated with a PerTronix ignitor module.

    This is a recent issue.
     
  17. Malcolm
    Joined: Feb 9, 2006
    Posts: 7,725

    Malcolm
    ALLIANCE MEMBER
    from Nebraska

    Did you ever figure out the problem?
     
  18. Kustom.Falcon
    Joined: Nov 1, 2010
    Posts: 502

    Kustom.Falcon
    Member

    Sorry for the delay.

    Yes, figured a solution: pulled the motor and gave it away.

    Sent from my DROID device using the TJJ mobile app
     
  19. westcoaster
    Joined: Sep 23, 2005
    Posts: 271

    westcoaster
    Member
    from SoCal

    now how are we going to sleep tonight? knowing that we'll never know what the problem was? :)
     
  20. fordor41
    Joined: Jul 2, 2008
    Posts: 948

    fordor41
    Member

    Also a bad PCV will make the exhaust loud but usually at idle.
     

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