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How big of a pain in the ars is installing tbi?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by **DONOTDELETE**, Jan 2, 2002.

    Ok, i've done all the searches and have a very good idea of the parts i need and actually have a line on danm neer all of it. what i want to know is how long does it take? how much friggin wire splicing is involved? How much hair will i pull out getting it all set up![​IMG] i looked at the wiring harness and it just made me want to run and hide. come on efi swappers, give me a time line and difficulty level. i'm trying to justify the cost and effort- and sanity loss.

    <font color=blue> Experience enables you to recognize a mistake when you make it again.

    </font color=blue>
     
  1. HarryH3

    HarryH3 1 ton status Author

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    I had to splice in 6 or 7 wires when I put a TPI engine into my '75. Most of the wires in that harness run directly from the engine to the computer, so you don't have to mess with them. The biggest PITA for me was re-plumbing the entire fuel system to handle the 47 PSI that my regulator is set at, and to provide the fuel return line from the other side of the regulator. I had to drop the tank and have another hard line welded into the top bung that holds the sending unit.

    It's been over 12 years since I installed mine, but here's a list of what I remember having to provide circuits for:

    ECM battery power
    ECM switched power
    Switched power to distributor
    Injectors (2 seperate feeds for TPI, may only be one for TBI)
    EGR Solenoid switched power
    Fuel pump power

    I put a LOT of time into installing mine, but that was long before so much (OK, hardly any!) swap info was available. I had to learn how it all worked and then figure out how to adapt it into my trucks wiring harness and fuel system. These days you can just buy a harness and slap it together over a weekend. [​IMG]


    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
    It's a great day to be alive...
     
  2. BurbinOR

    BurbinOR 3/4 ton status

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    Well TBI seems to be similar to TPI as far as swaps go, so lots of the same issues. Fuel delivery is important, the proper way is to replumb the lines for the increased pressure (tho for TPI it is wayyyy higher and therefore more safety-important), and use a standalone harness - maybe aftermarket that will make your conversion easy and keep the baldness factor at bay [​IMG]. The aftermarket ones are well marked and pretty easy to use, tho if you have a factory one that you can understand that will save you some $$. Gotta keep in mind things like VATS (anti theft system) - IF the original chip/harness has that as part of its system you will need to bypass via a chip change. For the record, I don't know if TBI vehicles have VATS to be honest with you. But it is something to consider.

    Timewise it could take you a day, it could take you a week. All depends on your homework, how much info you have up front, if you have all the hardware (fuel pump, etc.) and if you have help. So many factors, including your wrenching ability and tool selection, etc. Make sure the TBI manifold you have matches up to the heads you are using (some manifolds only match up to the post-87 heads, etc.).

    Overall the difficulty level is not extreme. Just doing the research up front is the key. Let us know if you need any more info or have any specific questions. Be glad to help.

    And if you decide to go TPI, look at the post from NRose07 about TPI stuff, heck, even if you don't go TPI, look at my response to him and the links on that post of mine for FI stuff.

    <font color=blue>'79 ONE TON TPI K5 - See it at---&gt;<a target="_blank" href=http://www.blazzinor.rockcrawler.com>www.blazzinor.rockcrawler.com</a>
     
  3. 3car

    3car 1/2 ton status

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    holley makes a 2bbl tbi that bolts to a 4bbl intake,and comes with everything you need to put it on,ecm,fuelpump,tbi,ect.summitt sells it for $709.my neighbor has one on his bronco and loves it.

    eatin'fords and shittin'dodges down in the sunshine state.
     
  4. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    I did mine as part of a diesel to gas conversion. I just bought the engine, complete with all accessories and brackets, along with engine harness (engine and dash) and ECM from a donor '89 Sub. I was told that the 87-90(?) TBIs are the simplest (fewer sensors, tranny hooks, etc.) but I am an EFI newbie so I can't confirm (still learning).

    So, for me it was really easy. Bolt in the engine and use the harness that came with it. Rewire my cab with the '89 sub dash harness, including ECM. Call it good.

    The only thing that has caused me any real trouble (other than as a direct result of my ignorance) was the fuel system. It uses these odd-ball metric o-ring nuts on the tubing. You can't (or rather I couldn't) find them anywhere. So, I cut the tube ends (including nuts) off some donor fuel lines, put a double flare on them (4 places - 2 lines going up the back of the engine and 2 going into the fuel filter), and plumbed the system using off-the-shelf brake tubing from NAPA. The I modified my diesel tank to take the pickup/pump from a TBI tank and called it done. You could also scavenge the complete fuel line system from a donor but that can be a pain getting it out without damaging lines or spending hours getting stuff out of the way.

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked
    Some day: 4" lift, 44" tires, massive cutting, shorter wb and rear overhang.
     
  5. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Most people here hate that Holley system. Do a search. Runs rich, no support, many headaches. Also, I bought an almost new crate motor, all accessories, wiring harness, and ECM for right at $1000.

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked
    Some day: 4" lift, 44" tires, massive cutting, shorter wb and rear overhang.
     
  6. 1bigk10

    1bigk10 1/2 ton status

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    Where did you find a crate with harness for that price?

    1982 K10 Silverado. [​IMG] 327 SHPE powerplant SM465/205,15"custom lift 38.5"TSL/SWAMPERS 12boltrearD44 front,3.73 gears.
     
  7. HarryH3

    HarryH3 1 ton status Author

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    Ya gotta look everywhere you can think of. Occasionally, deals pop up. I recently picked up a 454 crate, with 30K miles on it, complete with a Holley Pro-Jection and accessories for $1,500. The deals are out there, you just have to dilligently look for them. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
    It's a great day to be alive...
     
  8. MaxCrack

    MaxCrack 1/2 ton status

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    I would love to know where you got that motor. I kind of need one at the moment.

    A computer once beat me at chess, but it was no match for me at kick boxing.
    <a target="_blank" href=http://photos.yahoo.com/dana60manual>http://photos.yahoo.com/dana60manual</a>
     
  9. zakk

    zakk 1/2 ton status

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    what did you do about the VSS? That is my big problem right now. TH350 mated to a 203. Not sure who makes a VSS for a 203[​IMG]

    -zakk

    '77 1-Ton K5

    [​IMG] CK5's MOAB 2002 OR BUST!! [​IMG]
     
  10. HarryH3

    HarryH3 1 ton status Author

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    Zakk, check out <a target="_blank" href=http://www.howell-efi.com>www.howell-efi.com</a>. I bought my VSS adapter from them. It mounts inline with the speedo cable, right at the t-case. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
    It's a great day to be alive...
     
  11. BurbinOR

    BurbinOR 3/4 ton status

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  12. BurbinOR

    BurbinOR 3/4 ton status

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    Zakk, and whoever else reads this, I am not starting a flame war about VSS - we did that once and it did nothing but show how opinionated we all are [​IMG] - that said, you can do the conversion with NO VSS - been done many, many times and I have one of over 130 conversions my TPI guy did that does not have it. My truck runs better than stock and even saying that, I have an open mind and am probably going to put a VSS setup in my truck - heck, they are only $75 from Howell EFI so why not, right? Then I can judge if it runs any better, as it is claimed it does, or if it helps with gas mileage, which is the other claim. I hope it helps both, cause if it helps it run better, it will reallllllyyyyy run good then! Let ya know when I do it, but for now, your answer is you don't have to have it operational, but if you want it, check out that link HarryH3 gave. I just checked it, good price, and it probably work perfect for you. I have the same combo you do - T350 to an NP203, but I'm gonna try putting it in my engine compartment by the cruise control hookup.

    <font color=blue>'79 ONE TON TPI K5 - See it at---&gt;<a target="_blank" href=http://www.blazzinor.rockcrawler.com>www.blazzinor.rockcrawler.com</a>
     
  13. zakk

    zakk 1/2 ton status

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    my cruise control was the only thing that didn't work when i bought the truck. So i think i will wait for your work if it is REALLY needed. I want to get the swap done so i can drive it (my only set o wheels till i get the rally car[​IMG]) so getting it done is 72 hrs is the important thing.

    -zakk

    '77 1-Ton K5

    [​IMG] CK5's MOAB 2002 OR BUST!! [​IMG]
     
  14. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    I spent about 2-3 weeks calling any junkyard that might have one in the Phoenix area. Most I found were already missing stuff (alternators, already *hacked* out of the truck, etc.) or they were more than I wanted to pay. I finally lucked out at one. They had JUST brought in an '89 Sub 350 TBI that had a brand new crate motor in it. Hit in the front but still runs and it's absolutely complete. So, I drive over there and it still has the stickers on the valve covers, oil pan, block, etc. Runs like a top and it didn't look like it had been in there for more than a few months and a couple hundred miles. Anyway, I bought it on the spot complete and told them I wanted all the accessories, brackets, bolts, mounts, flex-plate, ECM, engine/dash harness, oil cooler, exhaust to the cat., etc. The only thing I didn't specify was the gauge cluster and I regret not getting it now.

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked
    Some day: 4" lift, 44" tires, massive cutting, shorter wb and rear overhang.
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

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    As a matter of fact, I talked to Howell about the VSS situation, and although the guy I talked to didn't seem like he was the one that designed their systems, (poor joke there) his answer about VSS and necessity was that if you were running EGR, you need VSS. That was about the only thing he came up with for a reason to run it. (guess that would give some idle and surging problems if it was inoperative and not a removed parameter) Most folks here aren't forced to run functioning EGR that have done a TPI swap, so not saying its necessary or not, but that was the word from an "expert".

    Didn't someone on here claim that adding VSS made a huge difference in the way their TPI runs?

    Since most of our trucks ('82-up at least) are set up for VSS anyways, it won't be hard to keep or add using stock parts, if that works for what people intend on doing.

    Since you are willing to try it, I can't wait to see the results! : )

    Personally, since TBI is relatively plentiful, MADE for these trucks, my vote would be find an 87-91 TBI equipped truck and swap the entire setup over. Heck, local yard has a '90 K5 in it right now. I'm going to get the tank one of these days, kinda steep at $100, and doubt that includes sending unit, but I'm not seeing many of these TBI trucks out there...


    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  16. BurbinOR

    BurbinOR 3/4 ton status

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    Well I just ordered the VSS from Jags that Run so should know within a couple of weeks, depending on how soon I can put it in. Looks simple enough, for my truck it will go in the engine compartment right off the cruise control and the wire hookup should be simpler. Let ya know...............

    <font color=blue>'79 ONE TON TPI K5 - See it at---&gt;<a target="_blank" href=http://www.blazzinor.rockcrawler.com>www.blazzinor.rockcrawler.com</a>
     
  17. HarryH3

    HarryH3 1 ton status Author

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    Are you getting a new chip to go with it? Sounds like your current chip doesn't have the VSS programming in it. Otherwise it would be setting the check engine light for "no VSS detected". Just wondering if your installer is gonna set you up for that.

    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
    It's a great day to be alive...
     
  18. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    <blockquote><font class="small">In reply to:</font><hr>

    if you were running EGR, you need VSS

    <hr></blockquote>
    I've been told that EGR is important to the proper functioning of a TBI 350. I do not have VSS and the EGR is bad. EGR for my truck is $60 (this is the cheaper generic). What's up with EGR/VSS? If I don't have one, can I ditch the other? Need a custom chip? I didn't get the instrument cluster with my engine (apparently that is where the VSS was) and I would rather not be forced to go get one. How does this work?

    Russ

    85 K30 CUCV, 350 TBI, TH400, 205, D60/C14, 4.56 Locked
    Some day: 4" lift, 44" tires, massive cutting, shorter wb and rear overhang.
     
  19. zakk

    zakk 1/2 ton status

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    You guys are spooking me now...

    -zakk

    '77 1-Ton K5

    [​IMG] CK5's MOAB 2002 OR BUST!! [​IMG]
     

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