Welcome To V6Mustang.com!

We are the oldest and largest V6 Mustang forum on the internet. If you have any questions about your V6 Mustang or just want to connect with other V6 Mustang owners around the world, you have found the best place on the internet to do that.

Registering is free and easy! Hope to see you on the forums soon!

How to determine TDC on 98 3.8L V6.

Discussion in '1994-2004 V6 Mustang Tech' started by snally68, Aug 21, 2014.

  1. snally68

    snally68 New Member

    Joined:
    Jul 13, 2014
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    1
    Ok so In my rebuild I'm installing the cam position sensor and when I installed the cylinders i set it at #1 cylinder TDC. But in reading up on the install of the CPS I missed where it mentions whether TDC is where the exhaust valve is open or the intake valve. So I may not have it set correctly. First rebuild so I'm learning as I go. Any help in clarifying TDC and also info on the CPS angle. I have found where it says 54* but also saw a 38* in another area. Thanks for any help you can give me.
     
  2. greensteeda

    greensteeda Retired Speed Racer Mod. Suck It!

    Joined:
    Feb 11, 2005
    Messages:
    19,082
    Likes Received:
    37
    Trophy Points:
    58
    Location:
    Nashville TN
    If the heads are on you will need a piston stop tool to find TDC. They are cheap from Summit racing or Jegs and easy to use. Here is a quick how to but I recommend buying the right tool:



    The cam and crank sensors do not care if you are on the intake or exhaust stroke as that is determined in the ECU. The Cam sensor rotates twice as fast as the crank so you will basically have 4 revolutions per engine cycle.
     
    Brent likes this.
  3. snally68

    snally68 New Member

    Joined:
    Jul 13, 2014
    Messages:
    22
    Likes Received:
    0
    Trophy Points:
    1
    Thank you for the quick reply. :)
     
  4. TonyDee

    TonyDee Active Member

    Joined:
    Mar 17, 2005
    Messages:
    624
    Likes Received:
    16
    Trophy Points:
    28
    Location:
    Winnipeg, Canada
    TDC, number one piston, both valves closed ( take valve cover off to check) put a straw in the cylinder ( remove spark plug, insert straw) rotate engine until straw is at the maximum height with both valves closed. Off course this is easier if all spark plugs are removed.
     
    Brent likes this.