Register Today It's free! This box will disappear once registered!

4.0 ohv performance rebuild

Discussion in 'Need for Speed!' started by Sebastian Vance, May 1, 2017.

  • Searches ExplorerForum.com
    1. Sebastian Vance

      Sebastian Vance New Member

      Joined:
      July 6, 2016
      Messages:
      12
      Likes Received:
      0
      Trophy Points:
      1
      Location:
      Spartanburg, SC
      City, State:
      Spartanburg, SC
      Year, Model & Trim Level:
      96 Explorer
      I recently hrydrolocked my motor(4.0 ohv) and believe I bent a rod because the engine won't turn over by the crank with the plugs removed. So I figured it would be a good opportunity to do a full overhaul on my 300k+ mile motor. And while I'm in there, may as well go all out! So my plan from reading posts from you guys, is as follows: my 95tm block bored as little as possible, comp 422 cam, my 95tm heads checked and milled for 988 springs by a shop, and mildly p&p by yours truly, along with the lower intake, 91tm pistons to up the compression, New crank, bearings, all seals and all gaskets. And of course a snorkel to prevent this happening again. I have a few questions that I need help with though. I have read that the 91tm pistons are heavier than mine. Do I need to get the corresponding year crankshaft to properly balance the engine? Will I immediately need a tune before I can drive it? And are there any other issues that I will run into? Its a 96 with obd2. And how long before I can rag on it again? I love my offloading.Thank you for your help and I'm sure i will have more questions as I go along.
       
    2. Support EF

      Join the Elite Explorers for $20 for 2 years!

      Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose fix problems yourself, and learn which modifications work without having to experiment on your own. Elite Explorer members see practically no ads, can add their own profile photo, upload photo attachments directly to your posts and Media Gallery, create more private Conversations, and more. Join Today. Your support is greatly appreciated.


      to hide adverts.
    3. Naasau

      Naasau Active Member

      Joined:
      January 2, 2007
      Messages:
      808
      Likes Received:
      1
      Trophy Points:
      18
      City, State:
      Denver Colorado
      Year, Model & Trim Level:
      '93 Explorer XLT
      Bump.

      I have no idea but I am interested in the answers that may be provided. I'm in a somewhat similar situation due to a rollover accident. Only I'm combo-ing with a body swap from donor.
       
    4. Sebastian Vance

      Sebastian Vance New Member

      Joined:
      July 6, 2016
      Messages:
      12
      Likes Received:
      0
      Trophy Points:
      1
      Location:
      Spartanburg, SC
      City, State:
      Spartanburg, SC
      Year, Model & Trim Level:
      96 Explorer
      So almost 8 months to the day we got her running again. I let her sit neglected for a long time then decided to knock it out. We started Thanksgiving weekend and it ran December 3rd at 1:30a.m.
       
    5. Sebastian Vance

      Sebastian Vance New Member

      Joined:
      July 6, 2016
      Messages:
      12
      Likes Received:
      0
      Trophy Points:
      1
      Location:
      Spartanburg, SC
      City, State:
      Spartanburg, SC
      Year, Model & Trim Level:
      96 Explorer
      So we got it to run and drive, just not very well yet. Modifications are: 90tm block and pistons with 98tm heads, heads polished and exhaust ports slightly opened up, 422 cam, EGR delete, no cat just a glasspack muffler. I can't remember all the vacuum stuff, I only have the brake booster and the fuel rail thingy hooked to vacuum. It idled on its own one time out of like 5 runs. There's a clutch problem so I only drove it like a block, but it bogged down and almost stalled. Haven't checked codes, kinda scared lol
       
    6. Sebastian Vance

      Sebastian Vance New Member

      Joined:
      July 6, 2016
      Messages:
      12
      Likes Received:
      0
      Trophy Points:
      1
      Location:
      Spartanburg, SC
      City, State:
      Spartanburg, SC
      Year, Model & Trim Level:
      96 Explorer
      Anyone know what all controls the idle?
       
    7. Turdle

      Turdle I bake stuff Staff Member Moderator Elite Explorer

      Joined:
      June 16, 2003
      Messages:
      27,993
      Likes Received:
      292
      Trophy Points:
      113
      City, State:
      Humboldt, KS
      Year, Model & Trim Level:
      2000 Mounty
      PCM and IAC control idle, provided the inputs from all the sensors are corerct and the PCM has entered closed loop.

      More important question that needs answered, what codes did you pull? With all the mods this would be the place to start. I wonder if the stock PCM can deal with the cam. If you have not deleted the egr from the pcm control ( illegal by the way) this might be an problem.

      My suggestion would be to pull the codes, then disconnect the battery to clear them while you reconnect the egr. Seriously, the egr is not going to take any performance from you and will just cause headaches while trying to eliminate it.
       
    8. Sebastian Vance

      Sebastian Vance New Member

      Joined:
      July 6, 2016
      Messages:
      12
      Likes Received:
      0
      Trophy Points:
      1
      Location:
      Spartanburg, SC
      City, State:
      Spartanburg, SC
      Year, Model & Trim Level:
      96 Explorer
      Yes I know the EGR is helpful and useful, but it wasn't functioning properly prior, and the pipe was damaged on removal. And my intake was really gross. This will be an off-road vehicle and seldom see street use. I will pull codes this weekend to see and let you know, I know that the EGR doesn't function at idle, so I thought it would idle fine without it. I have seen people on here report that the pcm will adjust to the 422, but maybe it has some learning to do from open loop diving?
       
    9. Sebastian Vance

      Sebastian Vance New Member

      Joined:
      July 6, 2016
      Messages:
      12
      Likes Received:
      0
      Trophy Points:
      1
      Location:
      Spartanburg, SC
      City, State:
      Spartanburg, SC
      Year, Model & Trim Level:
      96 Explorer
      Or closed loop whichever is when it learns stuff. Will the pcm save the new information once it learns or will it reset with every disconnection of the battery? I would like to avoid a tune for right now at least but it is eec-v so it wouldn't be too bad
       

    Share This Page







    We Support Our Troops!