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Technical SBC runs like crap

Discussion in 'The Hokey Ass Message Board' started by sideswipe, Jul 1, 2018.

  1. sideswipe
    Joined: Sep 27, 2012
    Posts: 198

    sideswipe
    Member

    Hello, I have a rebuilt 350 with 13K that I put on it. Now it runs like hell after normal temperature is reached and 60 mph. It seems to cut out when I put my foot down. I just replaced the distributor and timed it. No back fire or hesitation in park. I know think it is the transmission. A rebuilt 350 turbo with a shift kit. It has fluid in it but I think this is the problem. Any ideas for quick checks or tips? Thanks to all the guys that have helped me out before and happy 4th.
     
    chryslerfan55 likes this.
  2. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 12,602

    Johnny Gee
    Member
    from Downey, Ca

    Unclear so I have to ask. Did this happen after replacement distributor?
     
  3. alwaysamopar
    Joined: Oct 2, 2015
    Posts: 126

    alwaysamopar

    What ignition? Points? Hei? Carb? Vacuum advance assembly? What did you set timing at?

    Sent from my SM-G900V using The H.A.M.B. mobile app
     
  4. sideswipe
    Joined: Sep 27, 2012
    Posts: 198

    sideswipe
    Member

    This has acted up for awhile. I replaced the fuel pump and everything in the ignition thinking it was fuel or fire. I really don't think its the engine now. thank you
     

  5. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 12,602

    Johnny Gee
    Member
    from Downey, Ca

    Fuel filter in the carb was looked at and or external fuel filter?
     
  6. jetnow1
    Joined: Jan 30, 2008
    Posts: 2,152

    jetnow1
    ALLIANCE MEMBER
    from CT
    1. A-D Truckers

    Roller cam or flat tappet cam? Did it run right for a while then change? Was change sudden or gradual? Why did you replace the distributor?
     
  7. Blues4U
    Joined: Oct 1, 2015
    Posts: 7,589

    Blues4U
    Member
    from So Cal

    One of the most common things I see around here with threads looking for help is a poor description of just what the problem is. This thread too. So, the engine runs like crap, but maybe it's the transmission? I'm not sure how you get there. If the trans is bad, that usually means the clutches are slipping, so the engine will race, but there is no corresponding increase in speed. This is pretty easy to tell from an engine that starts mis-firing under load. Think about, which seems to be the issue. No sense in having guys trying to help you with an engine problem if the problem is with the transmission.

    So it runs well before normal temp is reached and once up to temp it starts to run poorly?
    So it runs well with no issues under 60 mph, but once it gets up to hwy speed the issue starts up?

    I'm not trying to be a pain in the ass, just trying to help you get some good information back. Clarify these things and the guys trying to help will have much better info to go on.
     
    jazz1, ClayMart, XXL__ and 8 others like this.
  8. sideswipe
    Joined: Sep 27, 2012
    Posts: 198

    sideswipe
    Member

    the car ran great for a long time. all filters are good and the only recycled old piece was the hei distributor so I replaced it with a new one. the car is fine at idle but i'm wondering once I start pulling up the hills and off flatland that the trans is not operating correctly. the problem seems to have been a gradual thing. I thought it was starving so I replaced the fuel pump. everything was built at a reputable shop. I am at the point where it I don't think its the engine.
     
  9. Vacuum gauge check yet?
     
    sunbeam and 6-bangertim like this.
  10. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 12,602

    Johnny Gee
    Member
    from Downey, Ca

    Cracked fuel line before fuel pump in either the hard steel line or rubber hose getting worse and worse? Minor blockage at fuel tank getting worse and worse?
     
    Black Panther likes this.
  11. sideswipe
    Joined: Sep 27, 2012
    Posts: 198

    sideswipe
    Member

    rubber lines have been replaced and no puddles or leaks. new tank as well. i'm getting plenty of gas to carb
     
  12. What, specifically does it do that makes you think the transmission is acting up?
     
    Blues4U likes this.
  13. F-ONE
    Joined: Mar 27, 2008
    Posts: 3,271

    F-ONE
    Member
    from Alabama

    Fuel.... dirty tank contaminated carburetor.... filters do nothing after the fact and they can only do so much before hand
    Faulty fuel pump
    Carburetor problems.....
    Secondary circuit problems
    Faulty floats
    Advance not working or set incorrectly
    Vacuum problems
    Out of time
    Faulty plug wires
    Valves not adjusted properly
    And on and on.....

    Reputable Shop???
    Assume nothing! Start with the basics and go down the list.
     
    INVISIBLEKID, bubba55 and clem like this.
  14. 59Tele
    Joined: Feb 5, 2016
    Posts: 129

    59Tele

    What F-One said: faulty floats, a definate possibility. I had a Quadrajet with plastic floats that went bad.
     
  15. First of all Quadrajets only have one float. I have seen hollow plastic ones and also hollow brass, replacement items but they are very rare. Most of them are nitrofil. How do we know it has a Quadrajet anyway? That could open up a whole new scenario if the secondaries aren't working.
     
    Last edited: Jul 1, 2018
  16. Blues4U
    Joined: Oct 1, 2015
    Posts: 7,589

    Blues4U
    Member
    from So Cal

    I tried to get him to explain this too, so far he's ignored both of us.
     
    Unkl Ian likes this.
  17. Blues4U
    Joined: Oct 1, 2015
    Posts: 7,589

    Blues4U
    Member
    from So Cal

    Just keep throwing more crap against the wall guys, some is bound to stick somewhere. Until this guy explains what's going on nothing you're offering really helps.
     
  18. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 6,250

    Ebbsspeed
    ALLIANCE MEMBER

    Why don't you take a video of the issue and post it? You seem to be having trouble describing what the symptoms are. Cutting out when you put your foot down does not sound like a transmission problem to me.
     
  19. sevenhills1952
    Joined: Mar 14, 2018
    Posts: 956

    sevenhills1952

    I just plugged in my crystal ball...it's warming up...there! The problem it says is...what tha?...a Chevy? I'm sorry
    Like others said ...troubleshoot. My wag would be (assuming good, clean fuel [no water or trash], assuming timing spot on (How was it built? Timing marks now may be meaningless) advance correctly working, if you stomp it and it's dead in the water sounds like accelerator pump...no "squirt". Do have another carb you could try on it? Try it down the road for kicks with air filter off?
    Back to ignition...you replaced HEI distributor...but are you sure you're getting 13.5v or so (running of course) to it?

    Sent from my SM-S320VL using Tapatalk
     
  20. Johnboy34
    Joined: Jul 12, 2011
    Posts: 1,588

    Johnboy34
    Member
    from Seattle,Wa

    Didn't get the answer he wanted so he'll probably throw more stuff at it. Engine runs like crap and transmission problems are a looonnnggg ways apart!

    Sent from my SM-G900V using The H.A.M.B. mobile app
     
  21. Gman0046
    Joined: Jul 24, 2005
    Posts: 6,256

    Gman0046
    Member

    Chinese distributor????
     
  22. studebaker46
    Joined: Nov 14, 2007
    Posts: 715

    studebaker46
    Member

    what everyone is telling you is a trans will not cause the problem you say you are having. My best guess if the car runs up to operating temp and then starts missing and stumbling is that choke is staying either the electric has become disabled or no choke hooked up and some how is in choke mode Tom
     
  23. X2 to what has already been said, pretty much ANYTHING BUT a transmission issue.

    vacuum leak is my 1st suspect though, runs fine until the choke opens/then too lean...we don't even know if it has EGR or emissions equipment at this point....
     
  24. s55mercury66
    Joined: Jul 6, 2009
    Posts: 4,335

    s55mercury66
    Member
    from SW Wyoming

    Carnac says....."Throttle cable needs adjustment"
     
  25. sideswipe
    Joined: Sep 27, 2012
    Posts: 198

    sideswipe
    Member

    sorry to off so long. when it hits a grade/hill there is loss of power to rear wheels. I thought it was hesitation (fuel, fire) but could this be a torque converter issue or modulator? I never open an automatic before. nothing Chinese on either haha
     
  26. randydupree
    Joined: May 19, 2005
    Posts: 667

    randydupree
    Member
    from archer fl

    The trannys thisalator may be stuck?
     
  27. No
     
  28. What the fuck is a thisaator ?
     
    INVISIBLEKID, rjones35 and Mr48chev like this.
  29. My guess is carb related.
    Either choke or vacuum unloader.
     

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