Anyone using the Holley EFI

Discussion in 'Pro-Touring' started by 2.5, May 17, 2018.

  1. 2.5

    2.5 Active Member

    Looking for someone that has done the Holley EFI swap. What fuel tank, regulator, pump, etc, did you use?
    Any experience in this conversion is appreciated!!
  2. BillA

    BillA Well-Known Member

    I swapped in a Holley Terminator EFI a few years ago and I'm very happy with it. It's pricier than some of the newer systems like FiTech or Holley Sniper but I think it's worth it. The ECU is fully tunable with a PC and the free Holley EFI software and if you venture in to multi-port EFI in the future all you'll need is a new harness. I used a stock tank that I drilled for an Aeromotive Stealth 340 in-tank pump (you can buy a fully loaded tank from Aeromotive, Rick's, Holley, Tank's Inc if you prefer). I also went with an Aeromotive regulator rated for EFI pressures. The Terminator is a return style system so you'll have to add a return line if you don't already have one. The Terminator prefers a single plane intake although I used an Edelbrock B4B and it ran fine. Just make sure you grind down the plenum divider or use an open spread bore to square bore adapter.
  3. 2.5

    2.5 Active Member

    Bill, thank you for the reply. I am currently trying to finish this swap but have ran into an issue. We went with the Tanks Inc tank with an in-tank Holly pump. The issue is when I go WOT the car looses fuel pressure and I was hoping someone else had experience with this. Based on what I am reading and talking to other people we have done everything that should have been done. There is something that I am missing, just have not found it yet.
  4. BillA

    BillA Well-Known Member

    I had the same issue on the chassis dyno causing me to cut that short until I diagnosed the problem. I determined the in-tank fuel pump I was using, a 200 lph Walbro, was too small. I swapped in a 340 lph Aeromotive and the problem went away. Do you have your fuel pressure regulator referencing vacuum? If you do make sure you are showing "0" vacuum at WOT on a vacuum gauge. If you still have vacuum at WOT and your pressure regulator is vacuum referenced you won't be getting full fuel pressure at WOT. Also, do you have the regulator on the return side?
    Last edited: Jun 11, 2018
  5. Robs455

    Robs455 Well-Known Member

    - Checkout voltage on the pump you should have at least 13V more is better
    - How is the pump mounted at the pickup? straight hose or a loop?
    - How much space is beteween the tank sock and the bottom?
    blyons79 likes this.

    NOTNSS Gold Level Contributor

    Starting my Sniper install soon. Subscribing to this thread..
  7. beaty0527

    beaty0527 Kenneth

    Installing Holley dominator, tanks inc tank with 255 Walbro pump. Still working on it so no feedback yet.
  8. Steve73GS

    Steve73GS 73 GEE YES

    Anyone swap out a tank on a 73GS for EFI application? Investigating different manufacturers for fitment and it seems 73 is not listed, at least with their standard tanks. Any help would be appreciated.

  9. Mopar

    Mopar Well-Known Member

    I also have been looking, but so far it seems the 73 -77's have been left out in the cold.
  10. Steve73GS

    Steve73GS 73 GEE YES

    Hmmm, ok. Will keep investigating and let you know any update Graham.
  11. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    Im using the Sniper EFI Set up. I'm using the Stock Tank but drilled a hole to add a return line fitting. I used the separate in line fuel pump kit from holley and have had no real issues. I will but saving up to purchase an EFI tank from summit. They run around $250. The nice in tank pump and sending unit runs about $200-300.

    Easy to see why I opted for the external Fuel pump kit for $200. If price is no concern, I would do the in tank pump. Once issue I ran across was the stock tank not having baffles to prevent the pump from pulling air when low on gas. I stalled out once going up a steep hill but I should have kept more gas in her.

    All in all I am happy with the fuel pump kit.

    Summit usually has sales going on.

    Here is the tank I have been Eyeballing

    Attached Files:

  12. Steve73GS

    Steve73GS 73 GEE YES

    I ended up getting a tank from Tanks for a 72GS. Not exact fit but close enough where it can be used. Kory @ Tanks was very helpful.

  13. Electra Bob

    Electra Bob Well-Known Member

    Also two thumbs up for Tanks Inc and Kory for support.

    Using one of their tanks for the Electra and it's a sharp looking (and sharp edged!) tank :)
    If they make one for your vehicle you can't go wrong.

    One thing to bear in mind if you go with an in tank pump is the feed line needs to be able to handle ~60 PSI I'm replacing all the lines on the Electra with Earl's Ultrapro. Some of what I'm taking off would definitely not take that kind of pressure.

    Brakes and fuel system - two things not worth going cheap on.

    Good luck!
  14. Mopar

    Mopar Well-Known Member

    What did you have to do to make the filler neck work?
  15. Steve73GS

    Steve73GS 73 GEE YES

    Yes, that is an issue. Will cut the filler neck off my existing tank and attach to the new tank.

  16. 2.5

    2.5 Active Member

    Update on my fuel issue. It was the tank. I reinstalled the old tank with the inline pump and the problem went away. I reinstalled the Tanks Inc tank and tried it with a little over a 1/4 of a tank of gas. The problem came back. I then filled the tank to apx 3/4 and the problem went away. I simply can not run below 1/2 of a tank of gas under hard acceleration.
    That's my story and I'm sticking to it!
    68Rivi_In_Cali likes this.
  17. 68Rivi_In_Cali

    68Rivi_In_Cali Well-Known Member

    I'm in the same boat. I can't run under hard acceleration or cornering with 1/4 left in a stock/ Chevelle tank . I think going to run an in tank pump.
  18. Electra Bob

    Electra Bob Well-Known Member

    I'm curious - is your Tanks Inc tank an 'EFI ready' one ? I used one on the Electra (but it was made for a different model) and the blurb says (and eyeballs confirmed) it has an internal well around the base of the fuel pump/sender to act as a kind of reserve under acceleration.

    I have had a couple of coughing fits in the Electra when pulling away on a steep incline but otherwise no problems. I'm babying the original engine so don't WOT it and can't attest to whether I would have the same issue there.

    68Rivi_In_Cali likes this.
  19. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    Its a more complicated install, but fuel supply issues when low on fuel is why I run a separate surge tank. A low pressure electric pump (or stock mechanical) to a reservoir and then the high pressure pump from the bottom of the reservoir. I was running a 2" diameter cylinder about 6" tall for years without issue, then decided to shrink it down to a 1" box tube about 8" in length and I seem to have some under load leaning out that I suspect is the surge tank, but could be another part of the fuel system I changed at the same time. In either case, I've successfully driven down to less than 2 gallons in the 20 gallon tank without hiccup.

    A decent sized sump and some baffling is really what a stock style tank needs to get to low fuel levels without starving the pickup. The Holley mat looks interesting, but is $$$.
  20. cruzn57

    cruzn57 cruzn57

    I have used the "holley mat" with good success, on a turbo buick swap, ( 45psi@ idle,70+psi underload,)
    surprised me, as I had fuel starvation at less then 1/2 tank before, but no issues after,

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