Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: 308 won't fire

  1. #1
    Night Rider Vombil's Avatar
    Join Date
    Feb 2011
    Location
    Western Suburbs
    Posts
    2,630

    308 won't fire

    Hi guys needs some ideas
    308 with around 100psi on each set of heads (just a quick rough test #1 and #2. Obviously compression is low but a couple mechanics have told me that should be enough to run. The car has been sitting for years. IT came off the road after the inlet manifold let go and water went in the oil. Heads look too clean to be the ones that were on the block when things went pear shaped. I think last owner may have changed them or at least given them a good clean. I have fuel (too much actually i think) and have spark. Does not even come close to firing. I have had this problem so many times and I have no frikken idea! Fuel, spark but won't run!

    I'm going to take fuel line off and just try it on 'start ya bastard' to strike off flooding.

    any suggestions? thanks..again

    also how can i tell if the block is a 76 or 86? it has elec ignition and blue paint but could have been painted blue as it's in a WB.
    BQZ

  2. #2
    Night Rider Innuendo's Avatar
    Join Date
    Aug 2012
    Posts
    3,447
    Quote Originally Posted by Vombil View Post
    also how can i tell if the block is a 76 or 86? it has elec ignition and blue paint but could have been painted blue as it's in a WB.
    Engine number should give that away. It will start with a V as opposed to Q or H.
    Selling HJ 253 Engine
    Engine Number QR718*** | 19M5 Clock Casting at 6 O'Clock
    19th December 1975 Suit HJ Late Dec 1975 to April 1976

  3. #3
    Banned
    Join Date
    Feb 2010
    Location
    Central West NSW
    Posts
    4,463
    Blue 308 motor will also be 11WT or 12WT (or even WT but that's highly unlikely).
    Are the lifters opening the valves? Pull the rocker covers off and turn the motor over and check.
    Is the timing correct?
    They will start with lobes gone off the cam and burnt out valves, so low compression shouldn't stop it altogether.

  4. #4
    Check timing is correct and firing order is correct

  5. #5
    1976 block has 308 on the leftside behind engine mount and 1986 would have it on both sides

  6. #6
    Banned
    Join Date
    Feb 2010
    Location
    Central West NSW
    Posts
    4,463
    If it's 86 it will be a black motor anyway. None of those prefixes I listed are correct. It will be V prefix.

  7. #7
    Night Rider Vombil's Avatar
    Join Date
    Feb 2011
    Location
    Western Suburbs
    Posts
    2,630
    Timing was 180 out ... Maybe?! These are a funny one. They have two tdc where #1 will pop the tissue out the spark plug hole when you crank. I'll probably look at that again now I think about it. When I've got it wrong in the past the motor will backfire heaps. It wasn't backfiring before or after I moved the dizzy. Previous owner had both neg and pos from distributor going to the negative on the coil?! It's so far away from sounding like it is firing I wondered if there was even spark. It definitely has spark at #2. Plugs are near new but look to have been super rich when it was last running. He said carby was overhauled. Acell pump on carbie works perfectly with two nice Big streams of fuel when you twist throttle arm

    - - - Updated - - -

    Also I forgot to mention that the only character prefix on the engine number I can read is T. Nothing before that. Then 793xx

    Will check for the two 308 castings on either side of block. I did notice that on an early red motor it was just the one side xx7
    BQZ

  8. #8
    Banned
    Join Date
    Feb 2010
    Location
    Central West NSW
    Posts
    4,463
    Red motor will have one centre bolt on the head/manifold. Blue and black will have two. Plus they went metric on the block about black motor. It won't say 308, it will say 5.0.
    There is two top dead centres per complete 4 strokes. Only one is compression stroke. The other is exhaust stroke. The timing marks will only line up when top dead centre is on the compression stroke. Set the distributor so it's pointing to number one plug lead then.

  9. #9
    Night Rider Vombil's Avatar
    Join Date
    Feb 2011
    Location
    Western Suburbs
    Posts
    2,630
    Thanks WB. Yeah tissue popped out of number 1 and rotor was facing 1 but timing mark was 180 out so I spun distributor 180. I've viewed valves while motor cranking and they appear to be moving.
    BQZ

  10. #10
    It's a rockin' Sandaro's Avatar
    Join Date
    Jul 2011
    Location
    Picton NSW
    Posts
    1,127
    Sorry to correct you WB, but timing marks will line up twice, both times with piston at top, trick is one is compression stroke and the other is exhaust stroke. That's why you could be 180 deg out with dizzy.

    Vom, on the compression stroke at TD both valves will be at rest (easy to tell if you've got the rocker cover off)

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •