EFI on 455

Discussion in 'High Tech for Old Iron' started by wormwood, Mar 30, 2013.

  1. wormwood

    wormwood Dare to be different

    DSCF4109.jpg hey all, I've been posting my progress in the x-bodies forums on my installation of MSD's "Atomic" EFI throttle body kit on my 75 buick skylark, but I thought that I would also post in here. I bought the kit last week and have been spending a couple of hours a day installing it. MSD's claim "install it in the day and cruise at night may be true for some out there but not even close for me. 1st off I went with MSD'd system because of 2 reasons 1) I already have an MSD 6A ignition box and a MSD pro billet distributor. 2) it seems to be the only EFI that can handle high horse power (provided you go with a return style fuel system). I also went with the "rotor phasing" timing control set up where the efi will control my distributor timing. I installed the control module under the dash next to the msd box to keep a sleek clean firewall. DSCF4107.jpg DSCF4109.jpg
     
  2. regal81455

    regal81455 Well-Known Member

    Keep the updates coming!! Ive got the EZ setup on my 464 and love it. Curious, having the "brain" next to your ignition module isn't going to cause you any issues with EMI? I know with the EZ system they really want you to mount it atleast 2' away.
     
  3. supremeefi

    supremeefi supremeefi


    It only controls it to a certain degree, it has limitations. It also has limitations on cold spark vs hot spark.
    Did they tell you that if anything goes wrong with the MAP, TPS, IAC or injectors that you have to send the whole throttle body back to them for repair? You do.

    Just an fyi, almost all of the TB kits need or will run with an MSD 6 and/or a one of their distributors.

    Only Accel, and the new Edelbrock and Holley TBI kits control spark the way it should be done, from cold start to hot running, with no limitations. They didn't tell you that either did they.
     
  4. boe

    boe Platinum Level Contributor

    re: "provided you go with a return style fuel system"

    can you comment more on this? What's limiting with the returnless fuel pump control that the Atomic offers? Do the atomic install instructions recommend fuel pressure regulated return style fuel system for higher horsepower applications?
     
  5. wormwood

    wormwood Dare to be different

    boe, the system suggests that you use a return fuel line with applications over 500 horse power. this is why i went with the atomic prety much the others all stop at 500 horsepower, themsd says it will handle up to about 620 HP. they also suggest that you use a pressure regulator on the line returning to the fuel tank.

    regal81455, they dont say anything about mounting it close to te ignition module. butthat is a good questio to ask, thanks for the idea.
     
  6. Ken Warner

    Ken Warner Stand-up Philosopher

    Most of the problems I've read with the various EFI systems have come from electrical noise or leaks in the exhaust system. One of the nice things about our engines having the dizzy up front is that it's pretty easy to keep the ignition related wires away from the EFI system wires. My MSD is mounted behind the driver side head lights, the EFI controller on the passenger side inner fender. I will admit the "octopus" of black wire loom behind the throttle body of the EZ-EFI system gives me some feelings of envy for the clean install look of the MSD system but with the air cleaner on you can't see it at all so it does not really bother me that much. On the other hand having everything integrated makes for a clean look but how is it for the purposes of sensor replacement or troubleshooting? The FAST system uses all standard off the shelf GM sensors and IAC so tapping into a connector/wire to determine what is giving bad data to the ECM is pretty easy.

    I have not done a lot of reading on returnless fuel systems for EFI but my gut reaction is that they are a fix for a problem that does not really exist. Running a return line to the tank is pretty low tech/easy/cheap and with about 30 years of long living return style systems being used by car OEMs around the planet it seems like a pretty solid way to go. Having a high current regulating circuit in the EFI controller trying to modulate the fuel pump makes me a bit nervous as well. As you can see in the pics my throttle body feeds from the front and returns at the rear through the little Aeromotive regulator. I made a simple bracket out of angle aluminum from the local Farm and Fleet store to keep it tucked up close and relatively clean.

    As I mentioned above MOST of the EFI problems on old cars like ours I read about relate to EMI and O2 getting where it should not be. One other problem relates to fuel pumps. A trip to the FAST forums will show you plenty of people that have had trouble with the Carter external pumps. In fact if you look around the net I think you will find most people with external pumps have issues. The exception might be the big Bosch external pump, I think Racetronix carries these now but if you read a bit and google a bit you'll find what you need. As Jim Weise mentioned on these forums a LONG time ago most of the electric fuel pumps out there are not rated for continuous (read that as day-to-day streetable) duty. So whatever you go with or do pay attention or keep a spare in the trunk. I like to take my car on trips a few hundred miles from home once or twice a year and the prospect of a huge tow truck bill (not to mention the kick in my pride) weigh heavily on me when choosing things for my car.

    Good luck and keep us appraised of what you do and how you do it.
     

    Attached Files:

    Last edited: Mar 31, 2013
  7. wormwood

    wormwood Dare to be different

    interesting note ken, the msd atomic high horsepower fuel pump kit includes the Bosch fuel pump. i may have made a mistake as to where i mounted the pump, tucked up under the rear bumper by the top of the fuel tank, but i will see how it it reacts.
     
  8. boe

    boe Platinum Level Contributor

    Good advise from all. Still leaning toward in-tank pump (already acquired) and returnless system (TBD).
     
  9. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    <--- Watching. I've had trouble with electric pumps losing their prime when mounted higher than the bottom of the tank. My currentl setup uses a surge tank with the high pressure pump located lower than the bottom of the surge tank.
     

Share This Page