Converting to fuel injection

Discussion in 'The Mixing shop.' started by buicklark225, Feb 7, 2020.

  1. buicklark225

    buicklark225 New Member

    I'm thinking about putting a fuel injection conversion kit on my car . Is it a good idea or should I just keep carburetor
     
  2. TrunkMonkey

    TrunkMonkey Well-Known Member

    It depends on a few things. And if you can post some of your questions you may have, there are a lot of folks who can answer them.

    EFI can provide some gains on drivability, fuel mileage, engine longevity (oil wash off/dilution/breakdown from fuel and such)'
    Gains in performance, throttle response and the like, are noticed by the "butt dyno".

    The car will often start easier, idle and run smoother.


    There are some pros and cons to the swap.

    Most fuel systems on vintage cars were designed for low pressure fuel delivery of less than <10 psi. (with a safety factor of several times that, but still much lower than EFI systems)

    You will need to modify some of the fuel delivery.

    Baffled fuel tank.*
    High volume/high pressure pump.*
    High bypass pressure regulator.*
    High pressure lines* (and line diameter of less than 3/8 may pose adequate volume)
    10 Micron filter at source and 40 at/near injector rail or throttle body.
    Fuel pressure gage (optional, but if you DIY, you need to set and be able to check pressures)
    Wiring, relays and fused/circuit breakers for the fuel pump.*

    Either the ability to "tweak and adjust" some of the settings, or someone who can do this.

    Now for the * specifics.
    FiTech has the "command center"(CC), that is basically a reservoir that sets in the engine bay and facilitates the original fuel delivery system to supply fuel to the reservoir, then the CC has high pressure/pump and gauges that provide "final delivery" of fuel to the Throttle Body(s). There are many folks who have used the CC with good results, and many who have had problems with them and abandoned the CC and installed the components I mentioned above.

    With the CC, your original tank, and fuel delivery are fine, as the CC becomes a miniature high pressure EFI fuel delivery point in the engine bay, near the EFI. (heat can be an issue in some cases).

    I put the 2x4 on my '64 Skylark (nailhead) and compared the cost of the CC vs replacing everything from the fuel tank to the throttle bodies and chose to skip the CC.
    My cousin went with the CC on his '69 Chevelle and had many problems (he has owned the car for more than 40 years) and is quite the wrench bender). He also recommended I skip the CC. I am pleased that I did.

    All that said, I want to add that I come from a background of aviation maintenance as well as automotive and drag racing.
    My father was killed due to fuel fire in a drag racing crash, so I am pretty much anal and OCD about some things, and that drives my responses and recommendations (as well as my opinions).

    "Overkill" is (one of) my call signs. :D

    Hope that helps.
     
    MRP and sriley531 like this.
  3. sean Buick 76

    sean Buick 76 Buick Nut

    I have converted some of my vehicles to EFI and others I still have Q jets on. I have no regrets about my EFI swaps.

    That being said a properly tuned carb is super good! my 75 Regal has a stock Q jet I rebuilt 10 years ago. I run an air fuel meter and data log the air/fuel and RPM. I can leave my Regal resting over winter for 6 months and it fires up in 10 seconds.i have perfect air fuel ratios with the Q jet, no improvement to be made really.
     
    Last edited: Feb 8, 2020
  4. Electra Bob

    Electra Bob Well-Known Member

    I did a Holley Sniper Quadrajet conversion on the Electra. The Sniper kit runs around $1,300 but by the time I added a new tank, sender, pump, regulator, filter, hose, fittings and various clamps and connectors that pretty much doubled.

    The FiTech command center would eliminate the need to change out tank and fuel lines and save a *lot* of crawling around under the car.

    Car starts easier, runs smoother and continually self-tunes.

    Bob
     
  5. sriley531

    sriley531 Excommunicado

    I installed a fitech system on my green car. I opted to use a tanks Inc fuel tank with an in-tank pump. I'm very pleased with the setup and do not regret it one bit.
     
    sean Buick 76 likes this.
  6. buicklark225

    buicklark225 New Member

    Thanks you guy's for the reply it really helps
     
  7. eagleguy

    eagleguy 1971 Skylark Custom

    I was considering the same swap. Just curious as to how much the whole conversion would cost if I took the car someplace to have it done. I currently have a Edlebrock Thunder Series 1806 that starts fine and runs well overall but stinks up my garage and gets poor gas mileage, not that I expect good gas mileage with a big block!
     
  8. Troys69GS

    Troys69GS Well-Known Member

    Quick question? I just installed mine, but I need the ball for the throttle cable. The carb q-j small one is not removable. What did ya do? Fitech on 455
     
    TrunkMonkey likes this.
  9. Electra Bob

    Electra Bob Well-Known Member

    TrunkMonkey likes this.
  10. TrunkMonkey

    TrunkMonkey Well-Known Member

  11. Mike T

    Mike T Well-Known Member

    Check this out. Can use the stock hard line, doesn't necessarily require a return line, or a baffled tank, plus it replaces/updates your fuel sender at the same time and it puts the 255LPH fuel pump in the tank where it belongs:

    https://www.holley.com/products/fue...uel_pumps/muscle_car_efi_modules/parts/12-303

    Don't forget to get a relay while you are there too:

    https://www.holley.com/products/fue...l_pumps/fuel_pump_harness_relays/parts/40205G

    You'll also need some fuel injection hose and clamps to connect:

    https://www.holley.com/brands/mr_ga...d_hose/budget_push-on/mr_gasket_push-on_hose/
    https://www.holley.com/search/?q=earls clamps

    I think Holley has free shipping this month.
     
  12. Mopar

    Mopar Well-Known Member

    Once again the 73-77 cars are left out.
     
  13. racenu

    racenu Well-Known Member

    Bob, I am about to install my sniper on the 69 wildcat, I read somewhere about electronic interference with air cleaner, stud, etc. Have you had issues you could share before I install my system. I have converted the distributor to electronic points, anything else I should look at to compliment the ignition system? Thanks Gordon
     
  14. Briz

    Briz Founders Club Member

    I'll send ya a piece of the nylon 1/4x20 threaded rod if ya need it. It comes in 2' lengths and ya need about 6".


    I put the Sniper on the Wildcat. Used the Holley terminator ext pump in back. Reused the factory 3/8 supply line and ran a new return line. Installed a bung in the tank. added the Hyperspark dist and believe it or not they have one for the Nailhead. First impressions were great. Ran it around town for a couple weeks. Felt safe enough for a road trip. after a 3 hours highway drive it didnt wanna start after fueling. After a few mins it cleared itself out and away we went. Next stop did it again. Next couple it was fine then on the way home it completely died and was towed the rest of the way. Kept thinking to my self if I'd left the carb and points it could have been fixed on the road side and Id be driving instead of on a flat bed. Now Im going completely through the system. changing a few things. If it happens again I'll pull and sell the system.
     
    stump puller455 likes this.
  15. Electra Bob

    Electra Bob Well-Known Member

    It's been a while and I'm getting older by the day... the only odd things I recall having to fiddle with were the trans modulator vacuum line having to bend the hard tube a bit for clearance and route it to a port on the front of the Sniper. That and the throttle ball. The stock air cleaner would not clear the fuel lines and electrical harnesses attached to the Sniper so I went with an after market one.

    I assume you have figured out where all the electrical bits and bobs are going to go. I mounted fuse blocks, relays a ground disconnect and power distribution block on the inner fender. Holley stresses the need for solid power connections 'Direct to the battery' so the power distribution block makes that a snap and a lot tidier. It has a multi post rail for both ground and positive connections. The disconnect switch is a lot easier than disconnecting a side post cable and saves time if you need to work on the car or store the car for a while without the clock etc draining the battery.

    Had to replace the stock coolant overflow tank to make room for all that. Once you get the Sniper running with the stock(ish) ignition you should seriously consider switching to the Hyperspark distributor, ignition box and coil. Gives the Sniper full control over ignition.

    Good luck!
    Bob

    Here's how I mounted stuff.
    Inner-fender-clutter.jpg
     
  16. racenu

    racenu Well-Known Member

    Thanks for the information, I should be able to figure everything out. I am mounting an A body fuel sending unit/pump into my wildcat tank. I got the sniper that doesn't require a return line. Just getting started, I have resisted going this route exactly why you needed a tow. These things are supposed to make life simpler, wish me luck
     
  17. Briz

    Briz Founders Club Member

    The block is a NO NO according to Holley techs. Thats one of the things Im changing.
     
  18. Electra Bob

    Electra Bob Well-Known Member

    The distribution block is directly attached to the battery with a disconnect switch on the ground side. Nothing else connects to the battery so the buss bars are basically an extension of the battery posts.

    The regular battery connections are attached to the buss bars and everything else is tapped off of the other posts.

    I've not had any issues with the Sniper or the ignition.

    Bob
     
  19. Briz

    Briz Founders Club Member

    I know! My thoughts exactly but Im doing it there way this time to see if it makes any difference.
     
  20. theroundbug

    theroundbug Well-Known Member

    Something nice about being able to drive timidly with the primaries of a 4 barrel carb and when you need MO POWA BABY you can turn it up.

    EFI doesn't have that same experience, but you get all the quality of life benefits. Sometimes the electric choke resetting after being in the grocery store just a minute too long gets really annoying. Waiting for your carb/intake to warm up on a cold day gets annoying. Knowing you're getting much worse fuel economy than your engine is capable of hangs like a cloud over your head. Filling the bowls after sitting for a while can get annoying.

    Gotta pick your poison I guess. Modern cars try to remedy this with "sport mode" and "eco mode" but to this day it has never felt like they nailed it yet.
     

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