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Technical Running/Shifting Rough

Discussion in 'The Hokey Ass Message Board' started by 440+6, Jul 29, 2020.

  1. 440+6
    Joined: Jul 28, 2015
    Posts: 44

    440+6
    Member
    from Illinois

    I hope everyone has been doing well, Its been a while since I last posted. Long story short I acquired a Corvair (with a four speed). I just got the carbs rebuilt and decided to take it out on the highway. It was fine until I got off and went home. At a stoplight I noticed that it idled rough. Further down the road I was in fourth gear going the speed limit 30, however when I put my foot on the throttle the speed didn't change and the spedo stayed at 30mph. At another light when I shifted into 1st it was very sluggish then picked up. Finally I heard backfire. I had this issue before, but that was fixed with a new set of points. This however sounded a lot louder than before. I know a lot is going, but any help would be much appreciated.
     
  2. wheeltramp brian
    Joined: Jun 11, 2010
    Posts: 1,023

    wheeltramp brian
    Member

    Condensor going bad is my thought
     
    bchctybob likes this.
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 46,872

    squirrel
    Member

    Spend some time looking at things. Throttle linkage, engine mounts, point gap, loose wires, loose carb mounting nuts, pcv hose, etc.

    Let us know what you find.

    Condensor might be it, they usually cause intermittent rough running, though.
     
    carbking likes this.
  4. If the car has been sitting, another possibility could be corrosion from the tank. Was the fuel fresh, and do you have an inline filter? It could be crap from the fuel tank.

    Because of the lousy fuel we have today, I experienced this with one of my trucks that had been sitting for a few years.
    Bob
     

  5. gene-koning
    Joined: Oct 28, 2016
    Posts: 2,027

    gene-koning
    Member

    If its been sitting for years, and you have not already done so, I would start by replacing every piece of rubber in the fuel system! The rubber hoses don't last forever, and modern gas doesn't help the old rubber at all. Gene
     
    Truckdoctor Andy and bchctybob like this.
  6. Agree that fuel lines and filters are the 1st thing to look at. Make sure the coil wire is all the way into the coil too.
     
  7. bchctybob
    Joined: Sep 18, 2011
    Posts: 2,506

    bchctybob
    ALLIANCE MEMBER

    Look at all of the throttle linkage to be sure there isn’t a worn out part that will mess up the synchronization (the carbs were re-synchronized when installed, right). I have an in-line fuel filter at each carb too.
    Also look carefully at the distributor. Clean? Broken or almost broken wires? Cap and rotor clean? After romancing the carburetors to perfection I found that the condenser wire on ours was broken, I installed a Pertronix conversion and it runs like a fine Swiss watch.


    Sent from my iPad using The H.A.M.B. mobile app
     
  8. ClarkH
    Joined: Jul 21, 2010
    Posts: 951

    ClarkH
    ALLIANCE MEMBER

    A problem with those Corvair Rochesters is that over time they develop leaks around the throttle shaft. A basic rebuild won't fix that. Try spraying some carb cleaner at the base of the carb where the shafts exit and see if idle changes--if so, they leak. Also, as @bchctybob said, they should be synchronized
     
  9. 302GMC
    Joined: Dec 15, 2005
    Posts: 6,267

    302GMC
    Member
    from Idaho

    Did you lube the dist. cam ? Sounds like your new points are closing up, or if they're new chinese points, they've failed.
     
  10. 440+6
    Joined: Jul 28, 2015
    Posts: 44

    440+6
    Member
    from Illinois

    Thanks for the reply and tuns out I had no compression in all of the cylinders.
     
  11. 440+6
    Joined: Jul 28, 2015
    Posts: 44

    440+6
    Member
    from Illinois

    I just figured it out, it has no compression in all of the cylinders.
     
  12. 440+6
    Joined: Jul 28, 2015
    Posts: 44

    440+6
    Member
    from Illinois

    I just figured it out it has no compression in all of the cylinders.
     
  13. 427 sleeper
    Joined: Mar 8, 2017
    Posts: 1,051

    427 sleeper
    ALLIANCE MEMBER

    Did the Timing gear's eat themselves? Maybe a broken cam key?
     
  14. lippy
    Joined: Sep 27, 2006
    Posts: 4,986

    lippy
    Member
    from Ks

    So it won't run at all now? Lippy
     
  15. 440+6
    Joined: Jul 28, 2015
    Posts: 44

    440+6
    Member
    from Illinois

    It seems like age nothing as far as I could tell was ever changed in the engine so it was running on original parts, and finally went after I pushed it too hard.
     
  16. 440+6
    Joined: Jul 28, 2015
    Posts: 44

    440+6
    Member
    from Illinois

    it still runs just not good at all.
     
  17. 440+6
    Joined: Jul 28, 2015
    Posts: 44

    440+6
    Member
    from Illinois

    As far as I could tell it was running on the original parts and I blew it after pushing it too hard it does seem like the piston rings however.
     
  18. bchctybob
    Joined: Sep 18, 2011
    Posts: 2,506

    bchctybob
    ALLIANCE MEMBER

    Well that’s a shame. The same thing happened with ours, a nice clean little car, it leaked badly but ran. I stopped the oil leaks but soon found very low compression.
    You didn’t mention what year yours is, ours is a ‘62 Monza. I didn’t think it was worth rebuilding the 145 so I bought a badly rusted ‘65 with a rebuilt 110 horse, 164 and swapped it in. It’s all stock except for the Pertronix but the car runs great now. I’d love to put the 140 horse heads and carbs on it with some headers, maybe someday.


    Sent from my iPad using The H.A.M.B. mobile app
     
  19. bchctybob
    Joined: Sep 18, 2011
    Posts: 2,506

    bchctybob
    ALLIANCE MEMBER

    Corvairs are very different to work on but easy. The engine and trans comes out with just a floor jack, jack stands and some end wrenches. The engines are great, like working on an aircraft engine.


    Sent from my iPad using The H.A.M.B. mobile app
     
  20. 440+6
    Joined: Jul 28, 2015
    Posts: 44

    440+6
    Member
    from Illinois

    That sounds pretty sweet and I would love to put headers on mine. Mine is not exactly Hamb friendly as mine is a 68 and I love it.
     
    bchctybob likes this.
  21. ClarkH
    Joined: Jul 21, 2010
    Posts: 951

    ClarkH
    ALLIANCE MEMBER

    You should love it, they are a lot of fun. I ran autocross with a '65 for several years, a long time ago; some wild rides keeping that rear engine behind me. If I didn't spin out on at least one run, it meant I wasn't trying hard enough.

    With a late-model Corvair ('65-'69) you're right at the Hamb's cut-off, which seems to drift between '64 and '65. The Hamb cut-off is more or less intended to eliminate muscle cars, which a Corvair ain't. In my opinion (for what that's worth) any late-model Corvair is Hamb friendly enough, as they were essentially unchanged from '65 onward.
     
    bchctybob likes this.
  22. '34 Ratrod
    Joined: May 1, 2019
    Posts: 33

    '34 Ratrod
    Member

    My son picked up a '62 Monza for $200, we changed the oil, put in a battery, put in some gas and started it up. We had to clean up the engine compartment because it was covered in feathers. Yes, feathers! Apparently the previous owners experienced an engine fire when they came into town off the interstate and used their down pillows to beat out the fire. No damage was done because we had no problem starting the car.
     
  23. bchctybob
    Joined: Sep 18, 2011
    Posts: 2,506

    bchctybob
    ALLIANCE MEMBER

    I kept all of the ‘65 four speed stuff, every nut, bolt, rod and bracket. Even the trailing arm brackets and the torque boxes. I would really love to upgrade our ‘62 with the later independent suspension. I’m afraid time isn’t on my side though, I have other projects to finish and I’m slowing down.
    I do wonder if anyone’s done it and how hard it was.


    Sent from my iPad using The H.A.M.B. mobile app
     

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