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To fuel inject or not to fuel inject... tis is de question!!

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  • To fuel inject or not to fuel inject... tis is de question!!

    79 CJ7 (pretty much stock and kinda wanna keep it that way) But I have major carb issues! Do I go ahead and fuel inject or just deal with the carb?!

  • #2
    Re: To fuel inject or not to fuel inject... tis is de question!!

    You would increase your horse power... you could go off camber... and you would spend a lotta money!

    Go for it!
    2010 Rubicon, Sprintex Supercharger with Sprintex Intercooler, DiabloSport T-1000 Trinity Programmer, Teraflex Falcon 3.3 Shocks ,1350 RE Reel Drive Shafts, Method 105 Bead Locks, Toyo 37" X 13.5" Tires, Custom Olympic Off Road Front Bumper, Olympic Off Road Smuggler Rear Bumper with tire carrier, Seward Radius 4s LED Light, Seward 12" LED Light bar, 50" LED Light bar with, sPod LED switch pod with Boost gage,, Rigid LED Lights, 15# Power Tank, Rock Hard Cage, Rock Hard Under Armor, Posion Spyder Sliders, Posion Spyder Crusher Fenders, Posion Spyder Evap Armor, Posion Spyder Extreme Duty Trans-Mount Cross Member, Bushwacker rear armor, 5.13 Gears, Magnum 44 Front Axle, Off Road Evolution "C" Gussets, Cobra 75 CB Radio, Warn 10K on Front and 8K Winch on Rear, Bartact Seat Covers, Delta Quad Bar Xenon Headlamps,Tantrum LED Offroad Rock Lights, Teraflex HD Tie Rod, Teraflex Falcon Steering Stabilizer, Teraflex Alpine Long Control Arms Front & Rear, Teraflex 4" springs, Teraflex JK Performance Slotted Big Rotor Kit, TeraFlex Monster HD Forged Front Adjustable Trackbar, Teraflex Monster Rear Forged Adjustable Trackbar, Teraflex Front & Rear Brake Line Kit, Teraflex Bump Stops Front & Rear, Surprise Straps, Hothead Headliner, Teraflex D-44 Diff Covers, Wild Boar Grille, Rigid Ridge Hood, Drake Hood Latch's,Synergy HD Ball Joints & a Tuffy Security Drawer

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    • #3
      Re: To fuel inject or not to fuel inject... tis is de question!!

      There are pros and cons both ways. First the old carburetors are tried and trued to be dependable and reliable. However, they do occassionally give people fits. Depending on how a carburetor is tuned will determine whether or not it will give any performance advantage or not. A properly tuned carb will not deliver any less horsepower than a properly setup EFI system. That said, a carb is tuned for altitude and temperature at the time it is being dialed in. Either one of those parameters change much and the "tune" is now out of tune. Climb a few thousand feet in elevation and the air gets thinner. A carb needs to be leaned by approx. 1.5% per thousand feet of elevation gain. A good EFI system can alter the air/fuel ratio and keep it much closer to stoichiometric on the fly whereas a carburetor would have to have the jets changed and depending on make/model of carb probably power valve changes and idle adjustments as well.

      In the past I used the Holley 4160 carburetor alot with the vacuum secondary and side hung float which would take quite an off camber hill before giving me much fuss as far as spilling over the vents or running lean. I used to love having my carbureted vehicles purr like a kitten due to the time it took to get them dialed in but nowadays there are so many advantages to a good EFI system.

      There are really only two downsides that I have found to an EFI system that did not come factory on the vehicle, one, investment cost. It is not cheap to install EFI onto a non-EFI engine. Especially take into accound, fuel pump located in the tank, sensors and wiring. Secondly there are several sensors that can fail which will render a vehicle dead in the water.

      The second is minor as electronic components are much more reliable and last much longer than two or three decades aga, however, they can still fail. It is a good idea to know your system and carry a spare component(s).

      Sorry, not much help but both are good systems when installed and dialed in correctly.

      Mike.
      2011 JKU Rubicon
      BDS Long-Arm Suspension System/ 17x9 ATX Crawl wheels/35" BFG KM2's/ Warn Powerplant/Plus much much more.

      http://My 2011 JKU Rubicon Build Thread

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      • #4
        Re: To fuel inject or not to fuel inject... tis is de question!!

        Hmmmm thank you! So I think I am going to go ahead and get a carb rebuild. have it "calibrated" for the place i wheel the most and see how it does?! I just hate it because when going up or down even slightly it DIES and will not restart till on completely flat groud! This is not good for wheeling in Moab as there is no such thing as flat ground!

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        • #5
          Re: To fuel inject or not to fuel inject... tis is de question!!

          Originally posted by Shenna View Post
          Hmmmm thank you! So I think I am going to go ahead and get a carb rebuild. have it "calibrated" for the place i wheel the most and see how it does?! I just hate it because when going up or down even slightly it DIES and will not restart till on completely flat groud! This is not good for wheeling in Moab as there is no such thing as flat ground!
          There are a bunch of books and repair manuals out there that do a pretty good job of explaining a carb rebuilt procedure if you want to attempt it yourself.

          A couple of little tricks that I used is when building a carb for off-road I would set the float level just a little lower than for a normal street ride which will help with splashing fuel over the vents. I have also used spring loaded floats to assist with the "bouncing" of the float which opens/closes the needle and seat irradically when the fuel is sloshing around.

          Mike.
          2011 JKU Rubicon
          BDS Long-Arm Suspension System/ 17x9 ATX Crawl wheels/35" BFG KM2's/ Warn Powerplant/Plus much much more.

          http://My 2011 JKU Rubicon Build Thread

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          • #6
            Re: To fuel inject or not to fuel inject... tis is de question!!

            Thanks Mike! I think I will find someone in the Salt Lake area to help me! To be honest I wouldn't know a carb if it was the only thing under the hood! (loves to learn but has no one with tools to teach) hehehehe

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            • #7
              Re: To fuel inject or not to fuel inject... tis is de question!!

              On a side note as well, with carburetion, keep the fuel lines away from any exhaust and/or heat source as vapor locking can be an issue to deal with. I generally tried to use one of two methods to feed fuel depending on how far the tank was from the carburetor. First I would use a low pressure electric fuel pump to feed an adjustable fuel pressure regulator or on longer chassis such as motorhome or four-door dually, I would use an electric pump to feed the mechanical pump. Vapor locking generally will not occur with pressure fed fuel, it is when you are pulling it (vacuum) that vapor locking can rear its ugly head.

              On another side note, not related to fuel, but I would check your grounding straps from the battery to chassis and chassis to engine. On hot days resistance really goes up and an inadequate ground circuit can really cause a drag on the starter motor due to the inability to pass current. I have seen many times either racing or off-roading when a vehicle would stall and the driver would try a restart, the engine would strain to turn over yet the owner would condemn the carburetor when in fact the starter motor just wouldn't spin the engine over fast enough to create a low pressure in the intake manifold and draw fuel from the float bowl through the idle circuit.

              I used to use two ground straps on motorhomes where the batteries were mounted a distance away from the engine and starter motor for this very reason. Heat soak on a starter motor can make people think they have carburetor issues.

              Mike.
              2011 JKU Rubicon
              BDS Long-Arm Suspension System/ 17x9 ATX Crawl wheels/35" BFG KM2's/ Warn Powerplant/Plus much much more.

              http://My 2011 JKU Rubicon Build Thread

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              • #8
                Re: To fuel inject or not to fuel inject... tis is de question!!

                That brings up another issue... VAPOR LOCK HELL!!!! lol

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                • #9
                  Re: To fuel inject or not to fuel inject... tis is de question!!

                  I am pretty sure i need a carb job as it hasn't had one in probably 25 years but, i also do have a vapor lock issue from hell! anything over 80 degrees and dang thing dies!!!

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                  • #10
                    Re: To fuel inject or not to fuel inject... tis is de question!!

                    Originally posted by Shenna View Post
                    I am pretty sure i need a carb job as it hasn't had one in probably 25 years but, i also do have a vapor lock issue from hell! anything over 80 degrees and dang thing dies!!!
                    Isolate, isolate and isolate the fuel lines from any heat source. Sorry I can't be more specific but each vehicle is different and I have found that each one requires its own unique formula for eliminating or reducing vapor lock.

                    Mike.
                    2011 JKU Rubicon
                    BDS Long-Arm Suspension System/ 17x9 ATX Crawl wheels/35" BFG KM2's/ Warn Powerplant/Plus much much more.

                    http://My 2011 JKU Rubicon Build Thread

                    Comment


                    • #11
                      Re: To fuel inject or not to fuel inject... tis is de question!!

                      That is okay you have been more help than anyone else! I appreciate it! And I will make sure whomever I find to work on my baby follows your advice!

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                      • #12
                        Re: To fuel inject or not to fuel inject... tis is de question!!

                        Glad to be of help. Let us know how it works out.

                        Mike.
                        2011 JKU Rubicon
                        BDS Long-Arm Suspension System/ 17x9 ATX Crawl wheels/35" BFG KM2's/ Warn Powerplant/Plus much much more.

                        http://My 2011 JKU Rubicon Build Thread

                        Comment


                        • #13
                          Re: To fuel inject or not to fuel inject... tis is de question!!

                          I have the Howell system on my 84 with a 4.2 and I love it. I've never had any problems with it. It starts up much quicker in colder temps and you can get the vehicle off camber and not have any problems. It's really a win win in my book. I will never go back to a carburator. When I swap to a V8 I will do an injections system as well.

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                          • #14
                            Re: To fuel inject or not to fuel inject... tis is de question!!

                            i was to add to this but it seems that most everything has been covered fairly well. like everyone has said, fuel injection is incredibly expensive, and generally speaking the easier it is to install, the more expensive it gets. On the other side, most people will say that once you swallow the pill of the how much you are going to have to dish out, the pros far outweigh the cons. And like has been covered if you can set up a carb correctly it can run just as well as fuel injection. I have contemplated this swap myself before and i couldn't bring myself to spend the money on it, but maybe that was just because i had too many things i wanted to do and when i listed them in order of importance this just fell way way down the list. i did have issues when going up and down hills, but i have solved them. i did it by doing like what was said and putting a new spring in, and setting the float lower than what it would normally be. this seemed to help my issues when going off camber. that and a little extra throttle helps. i have a hand throttle on my shifter so it makes it easier to accomplish this. so i guess i didn't really add much, but my post count is going up so i guess it doesnt matter haha...

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