New engine won't turn over

Discussion in '2005 - 2009 Specific Tech' started by atv4fun, Jan 10, 2012.

  1. I've built and installed a stroked 4.6l with a 9.5:1 compression ratio. The build went well until the engine was reinstalled. The engine will not turn over with the plugs installed. It turns over like mad with the plugs out. I've had the battery and starter tested, they checkout fine. I'm running out of ideas and things to check. I'm hoping that someone out there might have some other things I should check. Thanks!
  2. Valves opening?
  3. When you say it doesn't turn over what exactly do you mean?
  4. Yeah, I can only assume the valves are opening, I can watch the cams turning.
  5. The starter will not spin the motor with the plugs in. It will spin all day with the plugs out. I'm checking now to verify I've got the correct plugs.
  6. Sounds like timing may be off, who put the motor together?
  7. Can you turn it over using a breaker bar with the plugs in?
  8. No it won't turn over with a breaker bar when the plugs are in. With the plugs out I can turn it with a regular 1/2 ratchet, it's not easy but it will turn.
  9. It's been suggested that I reinstall the plugs, one plug at a time, turning the motor by hand between each plug. When it stops turning that might indicate the cylinder that has an issue. Seems like a logical approach, but time consuming, so it will have to wait for the weekend.
  10. I went through the whole routine of one spark plug at a time, no change. Rechecked every connection under the hood I could think of. Turns out the problem was electrical vs. mechanical.

    As part of the engine swap I was to relocate the battery to the trunk, so the battery was sitting on a stool next to the car. The jumper cables I was using to try and start the car with just could not pull enough amps to even turn it over, much less start a new tight engine. It dawned on me late Saturday afternoon that this might be my problem, so I dug out some old 1 gauge welding cable I had. When I connected those she started up on the first turn of the key. After the meticulous work building and install the new engine, in the end it’s something obvious or stupid that will trip you up. Oh well stuff happens.

    I’d like to thank everybody for the really great suggestions. I’ll post a link later today to a video we made at the moment of ignition. I won’t be posting all the videos we made of when it didn’t start, way to many of those…lol

    Thanks again!:)
  11. Are you kidding me??? Really? You were trying to use jumper cables from a battery and you didn't think to mention that? :chair:

  12. If I'd thought to mention it, it stands to reason that I would have then considered it a possible problem. Those jumper cables have always served we well over the years.
  13. :suicide:

  14. Video Link:
  15. your cams are probably 180 degrees off.