Where are my Small Block Chevy guru's at? Power problem.

Discussion in 'OT Driven' started by Moloko, Jun 24, 2009.

  1. Moloko

    Moloko New Member

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    So since I put my 79 Malibu together a few months ago, it's had a weird power issue. Off idle, with barely any pedal, it pulls away fine. Give it any more gas, and it doesn't do a thing. Basically, it goes harder at 1/4 throttle than at half or full throttle. I had a thought that the cam was in a tooth off, but I just took it apart and it's dead on.

    Here are the specs. It's a 260hp GM crate motor with the stock cam. Edelbrock EPS Performer intake. 600cfm Edelbrock carb. Stock pickup manifolds. Stock TH350 with stock converter. Highway gears.

    The engine also gets SHIT MPG. I've had 4 different carbs on it (3 600cfm Edelbrocks and one Demon 650) and no difference. It did it with the 2.5'' duals that were on the car when I first got it, and the stock Monte SS exhaust that I have on it now. Timing is set at 12 degrees initial, goes to about 44 total including vac advance. Fuel pressure checks out fine.

    I'm about to put this cam in it, just to see if it solves anything.

    http://www.summitracing.com/parts/CCA-CL12-205-2/
     
  2. jelloslug

    jelloslug OT Supporter

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    1) Are the secondaries opening?
    2) Have you rebuilt the distributor (changed the pick-up coil)?
     
  3. Jake!

    Jake! Guest

    check the plugs, plug wires, etc

    :dunno:
     
  4. Moloko

    Moloko New Member

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    EVERYTHING is new.
     
  5. MAD PUNK inDC

    MAD PUNK inDC Sic Semper Tyrannis

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    sounds like a timing issue. You sure the distributer isn't fucked?
     
  6. Moloko

    Moloko New Member

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    Yes, secondaries are opening. When they open, it falls on it's face, no matter what RPM it's at. I tuned the secondary opening with the demon, no change. The secondaries just choked the engine out no matter what RPM it opened at.
     
  7. Moloko

    Moloko New Member

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    It is advancing, and I even had an MSD box on it, still did the same thing.

    OH, forgot to mention, the engine WILL NOT rev pas 4k. It just stops.
     
  8. Ghost Load

    Ghost Load i'll see your kidcarson and geekboy and raise you OT Supporter

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    yeah right then you stalk me
    you didn't get an efi engine? those things are sooooooooooOOOooooo nice!
     
  9. Moloko

    Moloko New Member

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    Except in this case, it would do exactly the same thing because a carb swap didn't fix it.
     
  10. jelloslug

    jelloslug OT Supporter

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    You have too much fuel. Lean out the secondaries bigtime and go from there. Also, did you change the pickup coil in the distributor?
     
  11. flyinbrian

    flyinbrian New Member

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    What do the plugs look like?
     
  12. MAD PUNK inDC

    MAD PUNK inDC Sic Semper Tyrannis

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    double check everything with your ignition system, I swear this sounds like you got bad spark or a couple of wires crossed. If everything looks good otherwise, set your timing back a little. 18 deg initial and and see what that gets you. Other than that I wouldn't be able to tell you unless I was there in person.
     
  13. Moloko

    Moloko New Member

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    I didn't change the pickup. Also, the distributor is the only part re-used after the motor went in, even though I did install a new module and capacitor.
     
  14. Moloko

    Moloko New Member

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    Perfect, tan with no deposits.
     
  15. Moloko

    Moloko New Member

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    Would a pickup do this? I thought they were all or nothing.
     
  16. jelloslug

    jelloslug OT Supporter

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    I'm willing to say with 99% certainly that it's the pickup coil. I have seen this same problem 4 times now.
     
  17. Moloko

    Moloko New Member

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    I'll give it a shot, I'm sure the fucker is cheap.
     
  18. jelloslug

    jelloslug OT Supporter

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    They get intermittent and start to die at higher RPMs.
     
  19. Moloko

    Moloko New Member

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    I always thought it was a problem in the HEI module. Why would it be throttle dependent?
     
  20. jelloslug

    jelloslug OT Supporter

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    About 20 bucks. Make sure to get the gap right.
     
  21. Ivy Mike

    Ivy Mike New Member

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    Still sounds like timing to me although it could be the wrong camshaft in the thing or the cam wasn't installed correctly. Since you've already done carbs and ignition systems, I'd pull the cam and reinstall it making sure you've got the motor at true TDC before beginning. I don't think a SBC will run at a full 180 out but it could be.

    -edit- reading his last few responses, change the pickup coil first. If that still doesn't work, pull the cam.
     
  22. spooled2.2

    spooled2.2 OT Supporter

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    too much fuel.
     
  23. jelloslug

    jelloslug OT Supporter

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    The insulation on the coil starts to break down. At higher rpms the spark signal is not strong enough to make it through the failing coil and it just falls on it's face. The coils see to have about a 20 to 25 year life. I had a '74 caddy that had the very first HEI. It took forever to troubleshoot it in 1995 because it had never been a problem before then.
     
  24. Moloko

    Moloko New Member

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    I already have the cover off, and the cam is in right.

    Here is where it may get screwy. My friend had this car before me, and it had the stock 2bl on this crate motor and it ran fine. Well he decided to go fuck with it. He put a .510 lift cam in it, gear drive, 750 holley, etc. Well it ran like shit, so I got a deal on it. I put it together with the stock cam and it's current config, and it always ran like shit.

    Here is my one wacky theory. I'm wondering if this cam does not have some built-in advance or retard and by using an aftermarket performance timing chain if the cam timing isn't off somehow.
     
  25. Moloko

    Moloko New Member

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    The engine is already torn down to the longblock, so I'm already balls in now. It was leaking oil from the cam swap like a pig, so I need to put an oil pan gasket on it anyway. I think I'm just gonna throw that comp cam in it, a pickup coil, and see what happens.
     

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