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71 Cj5 Chevy 4.3 Liter With Efi

Discussion in 'Builds and Fabricators Forum' started by Simplegreen21, Feb 7, 2020.

  1. Feb 7, 2020
    Simplegreen21

    Simplegreen21 New Member

    California
    Joined:
    Apr 29, 2017
    Messages:
    15
    I have a 71 CJ5, it has the shorter front end. I would like to swap in a 4.3 liter V6. I haven’t really done much with truck engines before, so this feels a bit overwhelming to me and I hoping for some guidance.

    From what I have read the common swap includes pulling the entire engine, ECU, and wiring harness from a donor vehicle and swapping it in. I don’t think I want to go quite that route though. I would like to get an engine that would normally use a carb and use something like a Holley EFI, thus eliminating the need for the factory ECU and all the wiring/programming issues that come with it.

    First, I am trying to determine what year/version engine would allow this as most already have fuel injection and I don’t think they would accept a carb/EFI. Do I need to get a crate engine if I don’t want something extremely old and high milage?

    I think one thing I would need is a distributor, I found this one: A-Team Performance 4.3L 262 V6 EFI to CARB SWAP 65K Coil Complete HEI Distributor, Spark Plug Wires, and Pigtail Harness For Chevrolet CHEVY/GM GMC 90° V-6 One Wire Installation

    I am hoping to mate this to a SM465 transmission and use my existing transfer case, a dana 18 with a single stick. I have read through the Novak guide on this and it seems like a good combo.

    I’ve included some pictures of the tub I have been working on cutting out all the rust. It probably won’t be too pretty, but I wanted to see if I could do it anyway.

    Thanks!
    [​IMG]
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    Fly Navy and tomasinator like this.
  2. Feb 7, 2020
    scott milliner

    scott milliner Master Fabricator

    Seattle Wa.
    Joined:
    Dec 17, 2002
    Messages:
    2,029
    I bought a complete running truck for my 4.3 ltr swap. If you can. Find a rare 4.3 manual truck. This way you won't have to flash the ECM/PCM/VCM or what ever they call the computer. Oh. Stay way from 95' S10 trucks. I made that mistake.
     
  3. Feb 7, 2020
    Dphillip

    Dphillip Sponsor

    Omaha NE
    Joined:
    Nov 25, 2008
    Messages:
    251
    I believe the carbureted Chevy V-6 was late seventies to mid eighties with TBI starting around 1985 or 86. So those engines would be pretty old. Years ago we put a 4.3 with a carburetor in my friends CJ and that V6 came out of a 1980 El Camino. Late 1980’s and early 1990’s Chevy S-10 and Blazers all used 4.3 with a TBI and the junkyards are loaded with these simple but reliable engines.
    My suggestion would be to use a TBI on your 4.3 with a aftermarket wiring harness. This makes wiring up things very simple. I put a 4.3 in my CJ over 20 years ago that I pulled from a junked 1991 Chevy truck and used a Painless Performance wiring harness. You can’t go wrong with fuel injection.

    Also, your body work looks great!
     
    Rich M. likes this.
  4. Feb 8, 2020
    Jw60

    Jw60 Recovering Jeepaholic

    Sedalia MO.
    Joined:
    Oct 5, 2018
    Messages:
    405
    1985 a few 1986 and marine or crate are the only years for Carburetor on the 4.3 previous to that was the 200 and 229 v6 with dualjet carbs. You can put a quadrajet intake or tbi to carb adapter on but the fuel pump boss went away from the block in 86 along with several other major changes so unless you already had a 200 or 229 in the jeep there is no reason to look for an 85 block. Use 88 to 92 and get the tbi running in the jeep. stick it thru and don't look back.
     
  5. Feb 8, 2020
    47v6

    47v6 junk wrecker! 2020 Sponsor

    Washington DC.
    Joined:
    Oct 25, 2006
    Messages:
    4,725
    Did your jeep come with the V6 dauntless?

    here is your info
    General Motors 90° V6 engine - Wikipedia
    I am going to put a 2000 4.3 in my cj2a in front of a SM420. It is rated at 190HP factory. It had the SCPI fuel deliver which breaks and the MPFI has been installed instead with the distributor upgrade.

    I bought a GMC safari van running and driving for 500 bucks, stripped the entire wiring harness out of it along with the engine and 4l60 auto transmission. If I got the rare passenger drop transfer case, I could have had an automatic w OD. I decided I like shifting gears and want the d18 with an over drive for the Rube Goldberg experience.

    I spoke to Howell products and they will reflash my computer, but he said it will run with no modifications, just not right. He sold me on a reflash and a wiring harness to save me days of work and headaches.

    Any flywheel will not work, get the correct one for a manual s10.

    From my perspective, not using the native FI is a mistake as these parts are off the shelf available anywhere. This is what I am doing.
     
    Rich M. likes this.
  6. Feb 8, 2020
    Simplegreen21

    Simplegreen21 New Member

    California
    Joined:
    Apr 29, 2017
    Messages:
    15
    Thanks for the input guys! It seems everyone agrees sticking with stock fuel injection is the way to go. Does it matter if I get the engine/harness from a van vs S10? Would there be parts that the S10 would have that the can would not? I called a few junk yards a few months back and most seemed to have newer 4.3s from Silverados and none included wiring harnesses or any accessories. I am in Central California, does anyone know of a good place around here I could check out?
     
  7. Feb 8, 2020
    47v6

    47v6 junk wrecker! 2020 Sponsor

    Washington DC.
    Joined:
    Oct 25, 2006
    Messages:
    4,725
    I have the entire wiring harness out of the GMC Safari. Its a huge pile of wire... I spoke to the guy at Howell and he said it takes him 8-10 hours to trace every wire for the harness and discard the ones you don't need. I am buying a custom harness from him for like 500 bucks. Count the hours and multiply it by a fair rate to see whats its worth to you. Some things like welding in your motor mounts isn't easily outsourced, but plug and play is worth a lot to me.
     
  8. Feb 8, 2020
    Dphillip

    Dphillip Sponsor

    Omaha NE
    Joined:
    Nov 25, 2008
    Messages:
    251
    I don’t think there would be much difference in the wiring harness between an S-10 van or S-10 truck but it’s important to know what year your donor vehicle is. Throttle Body Injection was used on the 4.3 until about 94 or 95 I think? After that it was a Tuned Port Injection system that in my opinion is slightly more complex than the TBI.
    The TBI has a lower fuel pressure, only one Oxygen sensor and the ECU is easier to adapt to your build. No flash is needed just the proper chip to control the automatic transmission if you use one.
     
  9. Feb 8, 2020
    sterlclan

    sterlclan Member

    exploring the...
    Joined:
    Feb 21, 2009
    Messages:
    3,154
    ill echo earlier info , stay away from the 95 cpi injected 4.3
     
  10. Feb 8, 2020
    mortten

    mortten I can’t put my finger on it

    Peninsula, Ohio
    Joined:
    Apr 17, 2006
    Messages:
    1,274
    The later CSFI wasn’t much better. Still had the poppets.
     
  11. Feb 9, 2020
    masscj2a

    masscj2a Member 2020 Sponsor 2019 Sponsor

    Chester Mass
    Joined:
    Dec 27, 2013
    Messages:
    481
    Back a few years ago I installed a 4.3 out of a 2000 Bravado. Sent the computer off to Hollywood Hot Rod and they sent me back the corrected ECU with the necessary deletes and up dates for standard tranny, gear ratio, tire size. Think it was a four wire connect. It also included dual O2 sensors. Bought the correct flywheel from Advanced and swapped out the spider in the FI for the updated individual injectors. Ran with the very first turn of the key. I also installed a inline Bousch fuel pump attached to the frame. Installed the rear tank from a 71. Return fuel pressure was around 2 lbs. Can't tell you how well that combo ran, it was amazing. That motor was in front of a T15 and Dana 20 case with 18 guts and Terra low.
     
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  12. Feb 9, 2020
    Simplegreen21

    Simplegreen21 New Member

    California
    Joined:
    Apr 29, 2017
    Messages:
    15
    Thanks for all the help, I will keep my engine search going! While I do that I might as well make this a better build thread and cover what I have done so far.

    I bought the Jeep about 3 years ago thinking it was mechanically sound and just needed a little body work and some paint. You can see it looks pretty good in the picture below and i fired right up and seemed to run well.
    [​IMG]

    Unfortunately, that was not the case. The engine had a bad head seal and had to be machined. I thought that was good, but there was still coolant in the oil. Turns out there was a crack in one of the cylinder walls. I had the entire engine rebuilt, but a few months later there was knocking noise. Took it back and he said there was an issue with the cam shaft, which he fixed. It seemed good for a little bit, then it started to lose oil pressure when it warmed up. I replaced the oil pump, but the rear main seal went and it just pissed oil out the back. These series of events led me to where I am today, replacing the engine.

    Here is what I have done on the Jeep so far.
    First it had a keg as the gas tank, and while unique, wasn't really what I was looking for, so I got a new gas tank and moved it to under he drivers seat.
    [​IMG]

    I also built new seat brackets and put in new seats. The home made brackets that were in the Jeep were very poorly made and only attached in two places.
    [​IMG]
    [​IMG]

    I also replaced the front fenders as he had gotten the wrong size and just cut them to length and used self tapping screws to hold everything together. I replaced the wheels and tires because I would like a more classic look and this removed the need for wheel spacers.
    [​IMG]

    I removed the after market taillights and filled in the holes, I also filled in a whole that was cut in the back cargo area from when the keg was back there.
    [​IMG]

    So that more or less leads us to today where the whole Jeep is torn apart and I am starting over again. As you saw in the pictures above there was a lot or rust, which was hidden with bondo and paint. I started to see cracks and rust leaking through after a year or two, but I didnt realize how bad it was.

    This is my first project with a full sized vehicle, I have only ever done a small motorcycle before. I have learned a lot so far, especially that I should know a bit more about a vehicle before purchasing it. I will keep this thread updated as I make progress.

    Here's a picture of the 68 Honda CT90 I restored several years back.
    [​IMG]

    [​IMG]
     
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  13. Feb 9, 2020
    Fireball

    Fireball Member 2020 Sponsor 2019 Sponsor

    Pullman, WA
    Joined:
    Feb 9, 2018
    Messages:
    185
    Cool bike! Those things are a hoot.
     

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