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Technical Sbc first start troubles

Discussion in 'The Hokey Ass Message Board' started by Ponchoguy65, Jan 3, 2018.

  1. Ponchoguy65
    Joined: Oct 29, 2017
    Posts: 149

    Ponchoguy65
    Member
    from Midland,TX

    Hello all I'm ready to fire my goodwrench engine and I'm having some troubles the engine turns over but seems like I have no spark my timing light doesn't flash when turning over but it has backfired 2 times while turning so it must have some kind of spark I'm confused on this any help is appreciated some background on my build is chevy 350 into a 65 pontiac tempest hei hot sourced from pink wire on the ignition switch it is hot on the cap with switch in run position but the test light is off when in crank position on the bat terminal on the hei cap
     
    chryslerfan55 likes this.
  2. From your last thread on starter wiring,,,,
    The starter "I" terminal needs to run up to the coil, now to Hei. That's what it's for. The ignition switch does not provide power to the coil in start position.

    What's happening is when you let off the starter the hei gets power and the residual engine spin isn't enough to start it but enough to make it sputter.
     
  3. saltflats
    Joined: Aug 14, 2007
    Posts: 7,303

    saltflats
    Member
    from Missouri

    You may have to tie in the 12 volt bypass wire from the starter.
    This will give you 12 volts when cranking.
     
    Donuts & Peelouts likes this.
  4. Mr48chev
    Joined: Dec 28, 2007
    Posts: 21,836

    Mr48chev
    ALLIANCE MEMBER

    To add to that the HEI wants a lot heavier wire running to it to carry the added load that it calls for. I'm not sure if the "pink" wire has a resistance built into it or not but would guess that it does along with needing the bypass with that particular ignition switch.
     
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  5. Ponchoguy65
    Joined: Oct 29, 2017
    Posts: 149

    Ponchoguy65
    Member
    from Midland,TX

    Okay so which one is the I terminal on the starter? I have one wire on the side closest to the block and the other wire is on the large post with the main battery feed I'm not sure which of these wires feeds what I know one is purple one is red. Does the one that's on the large battery feed to the starter need to go hot to the distributor?
     
  6. Ponchoguy65
    Joined: Oct 29, 2017
    Posts: 149

    Ponchoguy65
    Member
    from Midland,TX

    Which is the bypass wire?
     
  7. saltflats
    Joined: Aug 14, 2007
    Posts: 7,303

    saltflats
    Member
    from Missouri

    There should be another small terminal on the solenoid marked I
     
  8. Ponchoguy65
    Joined: Oct 29, 2017
    Posts: 149

    Ponchoguy65
    Member
    from Midland,TX

    So I need to run a new wire from I terminal and tie into the wire I have going to coil? So id have 4 wires on the starter total?
     
  9. saltflats
    Joined: Aug 14, 2007
    Posts: 7,303

    saltflats
    Member
    from Missouri

    Should be 3 wires
    1 battery cable
    2 purple cranking voltage wire
    3 yellow wire from I terminal tied into the pink 12 volt wire at the distributor.
     
  10. Mr48chev
    Joined: Dec 28, 2007
    Posts: 21,836

    Mr48chev
    ALLIANCE MEMBER

    Stock ignition wire is black with a pink tracer. Here are two pages of the wiring diagram for 1965 Tempests. The second one shows the engine wiring. it should help decode things. I'd suggest saving them to you computer so you can expand them and be able to study them when needed. wiring-diagrams-of-1965-pontiac-tempest-part-1-e1324087834347.jpg wiring-diagrams-of-1965-pontiac-tempest-part-2-e1324088172488.jpg
     
  11. shawblock
    Joined: Dec 24, 2017
    Posts: 2

    shawblock
    ALLIANCE MEMBER
    from blueridge

    should be 2 small terminals & 1 large for the battery wire .. the 1 marked with S,, inside by block is your starting wire goes hot with key in starting position and should b purple//..2nd small terminal on outside of big terminal should have R that is for resistor to your hei positive side...also before i went and spun that fresh sb over to many more times i would double check timing marks...#1 to tdc on compression stroke then bring balancer mark on around to 12 degrees //mark #1 on distributor housing and and aline with rotor ...gives a good start and fer sure fire if everything elese is n order ...i just fired a fresh 355 last fri it fired on 2nd revolution.. i played with her from there . she sounds so good shed make a tadpole slap a whale//
     
  12. Chevy guys: No solenoid 12v boost on Pontiacs. It comes from IGN 2 on the switch.

    If I had to guess so far, distributor 180 deg. out.
     
    Ralphies54 and LOST ANGEL like this.
  13. Red herring-
    Chevy engine with no power to HEI in start position.
     
  14. Blues4U
    Joined: Oct 1, 2015
    Posts: 1,821

    Blues4U
    Member
    from So Cal

    That was my first thought too.

    Just seems like Ponchoguy sure has a lot of questions and problems with things that should be pretty basic. Am I wrong to think that maybe he should stop what he's doing and spend some time learning how basic systems are designed and are supposed to work? It would pay off in the long run. He'd spend far less time posting here asking questions and struggling with these things. Maybe I'm wrong, maybe that's what this forum is for, but dang, sure seems to be a lot of posts on what should be pretty basic level things. Just posting every time you hit a snag seems like a real long way to go about things. Is this the internet equivalent of giving a man a fish instead of teaching him how to fish?
     
    wbrw32 likes this.
  15. Now he does, Vick. See update
    Not a red herring when you've got the guy looking for the R terminal wire that's not there.
    IGN 1 should stay live when cranking . It is the resistance wire.
    IGN 2 is the 12v kicker that takes the place of the solenoid kicker on Pontiacs.
    Both terminals should stay hot during cranking.
     
    Atwater Mike likes this.
  16. Ponchoguy65
    Joined: Oct 29, 2017
    Posts: 149

    Ponchoguy65
    Member
    from Midland,TX

    Okay I've got heat on the coil now crank and run....the engine started but sounds rough as hell and backfires out the carburetor any idea what tricks to try to get it to run right so I can brake her in?? Thanks again guys!
     
  17. Not really a trick , but do you have timing light? Shop manual?
     
  18. The Basics are the tricks
    Every shop manual covers the basics.

    Bring #1 up on compression
    Check that rotor is pointing at #1 plug wire.
    Double check plug wires to firing order.

    You're looking for a mistake so be methodical.
     
  19. Ponchoguy65
    Joined: Oct 29, 2017
    Posts: 149

    Ponchoguy65
    Member
    from Midland,TX

    I have shop manual and timing light on it but it doesn't seem to light up when its running its a el cheapo light from jegs and I forgot to mention the holley 4150 actually caught fire for about 30 seconds
     
  20. Ponchoguy65
    Joined: Oct 29, 2017
    Posts: 149

    Ponchoguy65
    Member
    from Midland,TX

    I have msd tape on balance I'm looking like roughly 12 degrees advance
     
  21. Mr48chev
    Joined: Dec 28, 2007
    Posts: 21,836

    Mr48chev
    ALLIANCE MEMBER

    It can't be said any better than that.
    What can be added is don't assume that the timing is right or the wires are in the right firing order, check it out just as it was a fresh engine you just put together.
     
  22. All that backfiring thru a holly you can plan on in needing some parts now.

    Fire in the intake means sparking with intake valve open. Double triple check the plug wires. Mixing up 5&7 is quite common
     
  23. saltflats
    Joined: Aug 14, 2007
    Posts: 7,303

    saltflats
    Member
    from Missouri

    Remember to run the plug wire as a Chevy not a Pontiac.
     
    scrap metal 48 likes this.
  24. Budget36
    Joined: Nov 29, 2014
    Posts: 1,509

    Budget36
    ALLIANCE MEMBER

    Didn't Holley fix that problem with some plugs several years ago? I recall plugs being sold, to save the power valve?...but thought Holley incorporated it into their carbs.

    But regardless...fire isn't a good thing....
     
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  25. Mr48chev
    Joined: Dec 28, 2007
    Posts: 21,836

    Mr48chev
    ALLIANCE MEMBER

    If you put a timing tape on it you have to have made sure that #1 piston was on top dead center when you put the 0 of the tape on the damper. You don't just stick it on the damper lined up with the old mark and assume that it is correct.
    It should be noted that a lot of long pump sbc engines have the stock timing mark at 12' O'clock along with the timing tab and the tube for a scope's timing light pickup.
    First step is still as 31Vickywithahemi said, Pull number 1 plug and bring the piston up on top dead center of the compression stroke.
    Then make sure your marks are right.
    Then check your firing order That would be like in this diagram. SBC Hei firing order.gif
    Even the best of us have crossed #5 and #7 wires at one time or the other it should be noted.
     
    olscrounger likes this.
  26. 48, Good point on the tape placement.
    I don't see the need for it, however.
    This is supposed to be a daily driver. Tape won't hold up anyway.
    A factory crate motor should come with a damper, and correct pointer /tab.
    Of course you can never assume everything is correct there, but I don't think we're quite ready for the Finding and Marking TDC class yet here.
    Chevy Guy, Maybe you should invest in a dial back timing light if you feel the need to total time it.
     
    Ponchoguy65 likes this.
  27. Ponchoguy65
    Joined: Oct 29, 2017
    Posts: 149

    Ponchoguy65
    Member
    from Midland,TX

    The
    The carb should have powervalve blow out protection though I know that's a limited feature...and ill double check the 5 and 7 wires again tomorrow and the engine came with a timing tab for my 6.75 inch balancer its on the engine driver side and ive confirmed at 0 on the balancer no 1 is at the top of compression stroke so im thinking a plug wire is off somewhere as stated before. Keeping fingers crossed that power valve is still alive
     
  28. We aren't there, but what has happened to the splice just before the coil? Wire changes to pink/black after splice going to coil. That splice is where the magic happens, and in this case for HEI the resistance wire should be replaced with a standard wire.

    It's been 10 years since I had a tester on the ignition circuit or switch of that era Pontiac and I don't recall one way or the other the "ignition 1" remaining hot during crank. I sorta pulled from the most recent exposures where it doesn't. Brings up a good question though, should one wire the Chevy engine like a Chevy or wire that Chevy engine as the Pontiac it resides in? Personal choice I guess.

    At the Lower bulkhead connection - the wires change colors . On pin 1 of the connection the resistance wire and pink ignition fron ignition 1 origin. On pin 7 the yellow and black -yellow of ignition 2 origin.

    image.jpeg
     
  29. Ponchoguy65 and Blues4U like this.
  30. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 3,926

    Ebbsspeed
    ALLIANCE MEMBER

    Using your instructions, the distributor will be off by 174°. TDC on compression stroke plus nearly 1 additional turn on crank to 12° BTDC is 348° at the crank, or 174° at the distributor.

    You must know how to do it since your engine started right away, but your explanation is not accurate.
     

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