'78 EVAP system with LT1 install/fuel ???'s

Discussion in 'High Tech Retrofits' started by sbca96, Apr 6, 2008.

  1. sbca96

    sbca96 Veteran Member

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    OK, I am trying to get my '78 Camaro to pass smog prior to pulling the motor
    for an LT1 swap. The car passes the sniffer test at the exhaust, but has not
    been able to pass the new EVAP test. I pulled the tank and had two leaks in
    the neck and AVAP line sealed, but now they say its between the tank and
    the canister. I found that NPD carries this line in stainless steel for 90 bucks,
    but I dont want to replace it if I cant use it with the LT1. I downloaded the
    PDF done by ULTM8Z, but it doesnt mention the EVAP system. I also wonder
    if I can use a stainless steel line for the pressure, and the stock feed line as
    the return. The wife wants this car running with the LT1 ASAP so I will have
    a lot of questions as I quickly get the ball rolling. The engine is a '94 Firebird
    LT1 with 67k on it.

    On a side note we were recently forced off the road by an SUV, and totalled
    her '95 Camaro Z28 with 192k on the engine and 66k on the trans. I will be
    offering that up for sale soon. It was her baby, and shes devestated.

    [​IMG]

    [​IMG]

    Tom
     
  2. ULTM8Z

    ULTM8Z Veteran Member

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    What are you running for fuel line? Earl's type braided line?
     
  3. sbca96

    sbca96 Veteran Member

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    Sorry for the confusion, no currently the '78 is all stock, 305/auto. I want to
    get it to pass smog prior to pulling the engine to install the LT1, but I dont
    want to spend anymore money on parts I cant use after the swap. So I am
    checking to see how others did their EVAP system. Can I use the stock EVAP
    thats in the '78 for the LT1, and reuse the line? If so, then I will buy the SST
    line from NPD and install it to pass smog, then carry it over to the LT1 setup.

    As far as after, I would like to run SST lines and not nylon or braided. I read
    the downsides of the fuel vapor with the braided line.

    Would the Rock Valley tank have provisions for EVAP, supply and return?

    Thanks for your help!!

    Tom


     
  4. ULTM8Z

    ULTM8Z Veteran Member

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    I think you'll need to convert to the LT1 EVAP. The late model stuff uses an electric solenoid to turn the vacuum on and off to the cannister and that solenoid is controlled by the PCM. Although your car will likely run ok with the '78 system, for emissions you'll probably have to do the conversion to the LT1 system.
     
  5. sbca96

    sbca96 Veteran Member

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    Good point, I bought the Painless wiring harness, but I read that there is a
    "smog" harness that is used along with that one?? I wonder if I can use the
    LT1 canister in the front, in the '78 location, and use the SST line to get the
    fumes to the front? That way I can reuse the EVAP line that I need to put
    on the '78 system to get it to pass. I would assume that the canister and
    solenoid wouldnt care if its in the drivers rear fender or the drivers front. Is
    that what others have done? I am assuming that I am not the first to try
    and retain the EVAP to be California legal.

    Hopefully this is helpful to others doing the same thing with a 76+ model.

    Tom
     
  6. ULTM8Z

    ULTM8Z Veteran Member

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    That's what I did. My steel factory '71 EVAP lines are meant to work with my '71 fuel tank configuration. But the TPI charcoal cannister works equally well with this. Now, I haven't attempted an emissions inspection with my setup, so I can't say for certain this will work in that regard. But vent lines are vent lines, AFIK.

    Yes, Painless has an emissions harness that is sold separately.
     
  7. 79ZED

    79ZED Veteran Member

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    First, do you have to pass a visual for the Evap canister and lines? If so, then you'll have to use the '78 cannister with the 305, otherwise it wont match the vacuum diagram on the rad shroud.

    Second, doesn't the LT1 EFI engine have the canister solenoid at the intake manifold? If it does, then all you'll need when you do the engine swap is the rubber purge line from the LT1 canister hooked to the solenoid. You could use the original canister but a couple of vacuum lines would need plugged.

    Either way, you can go ahead and order the 1978 steel line for the evap cannister and use the original rubber line to hook up the canister of your choice. That shouldn't be a problem.

    John
     
  8. sbca96

    sbca96 Veteran Member

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    Honestly I am not familar with either system enough to tell you where each
    item is (solenoid) which is why I posted this up. Thats the info that I need
    though, so I will order the SST line, and the smog harness from Painless to
    make the car legal in California. I will have to work with Rock Valley for the
    fuel tank, or my other plan was to use a Buick Regal EFI tank.

    Tom
     

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