Results 1 to 6 of 6

Thread: Fuel for SVO

  
  1. #1
    Just a bit of BOOST
    Join Date
    Apr 2020
    Location
    Sandwich, MA
    Posts
    3

    Fuel for SVO

    Hi all,

    I'm a new SVO owner having purchased one last week. It is in mostly original condition with just under 60,000 miles and running great.

    I have 93 octane fuel in it with the switch in the premium position but I don't seem to ever get the full boost out of the turbo. When I first took possession it had some 87 in it and had been filled with 93 so I left the switch in the unleaded/regular position and it seemed to max out at just under 8 on the boost gauge.

    Filled it with 93 a couple times and switched to premium mode, it was getting just over 8 - call it 9 on the gauge. I then added a can of Lucas octane booster and then filled up again and the boost gauge is getting up to the line between 8 and 12 - assume that is 10. My thought was some knocking was detected and boost was limited.

    So I'm wondering if the gauge is off, if fuel could be an issue (maybe I need to get some that is ethanol free?) or any other insights. I'll admit I haven't been paying close attention to if I hear any pinging which I'll try to be more aware of.

    I'm also very new to the SVO and learning about how it operates
    (had a few other Fox bodies in the past)
    .

    Thanks,

  2. #2
    Just a bit of BOOST
    Join Date
    Apr 2020
    Location
    Sandwich, MA
    Posts
    3
    Ah, guess I should have mentioned this is an 86 so my under standing is the max boost is 15.

  3. #3
    OVER-BOOST!! 86-TC/SVO's Avatar
    Join Date
    Apr 2002
    Location
    Connellsville,Pa
    Posts
    606
    SVO's: 86 1C X2
    Factory gauges are always off.

    How old are plugs, wires, cap, and rotor ? When was the fuel filter changed last ? Original fuel pump ? These are some of the things to look into. Depends on if you're wanting to leave it stock or upgrade a little. Fresh tune up. Changing the fuel filter. May need to get injectors cleaned. Fuel pumps were never up to par from the factory. If you upgrade the fuel pump you'll need to add a adjustable fuel regulator.

  4. #4
    OVER-BOOST!! GAboySVO's Avatar
    Join Date
    Dec 2002
    Location
    Acworth, GA
    Posts
    3,294
    SVO's: 2 - 9Ls
    If you are not getting 15psi in premium mode, then there are a couple things to check. First is the boost control solenoid (BCS). Check the coil for continuity and apply voltage to confirm actuation. You might want to pull the BCS apart and clean inside. Mine had oil in it from the PCV system.

    Confirm that all vacuum hose to the BCS are crack free. I would just replace them to be on safe side.

    I think there is a fuse link in the circuit from the premium switch to the BCS. Double check continuity.

    Another thing to check is to remove and clean the VAM. It may be getting stuck/not opening all the way. While you are there, you can verify the bellows hose has the reinforcing spring inside that prevents it from collapsing.
    Mike S

    '86 SVO 9L Leather
    '86 SVO 9L Road Warrior
    '96 300ZXTT

  5. #5
    OVER-BOOST!! gbeaird's Avatar
    Join Date
    Apr 2002
    Location
    Pearland, Texas
    Posts
    2,159
    SVO's: '86 2R
    Welcome!!

    If it seems to run and accelerate well, I'd expect the fuel system and ignition to be in decent shape. You may want to pull the plugs and check their condition and gap. Many people think that wider gap is better, but not on a turbo. Too much gap and you can 'blow the fire out' under boost. Run factory gap only.

    Also, verify the hoses and connections between the turbo, intercooler and throttle body are in good shape and snug, but not overly-tight. Make sure the vacuum hose between the turbo and the boost controller is not split.
    Gene Beaird,
    86 2R SVO, G Stock,
    Pearland, Texas

  6. #6
    Just a bit of BOOST
    Join Date
    Apr 2020
    Location
    Sandwich, MA
    Posts
    3
    Ok, thanks for the tips. I will look into all.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •