Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

TBI fuel pump

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Cavalry, Jun 23, 2001.

  1. Cavalry

    Cavalry 1/2 ton status

    Joined:
    Oct 1, 2000
    Posts:
    978
    Likes Received:
    0
    Location:
    upstate NY(although I cant figure out why)
    Anyone know if a GM tbi in tank fuel pump can be modified to external type. I have the ability to machine parts, I just dont have a pump to look at to see if it can be done.

    "There is a fine line between hobby and mental illness"
    Luke
    84 K5
     
  2. Triaged

    Triaged 1/2 ton status

    Joined:
    Feb 21, 2001
    Posts:
    3,808
    Likes Received:
    0
    Location:
    CA (LA/OC area)
    I don't think so. The out of tank ones have a hose barb for the fuel line from the tank. The in tank does not.

    '71 Blazer CST with alot of rust
     
  3. HarryH3

    HarryH3 1 ton status Author

    Joined:
    May 31, 2000
    Posts:
    10,384
    Likes Received:
    2
    Location:
    Georgetown, TX
    You'll need to use a pump designed for external mouning and also fab a pickup tube to replace the existing in-tank pump.

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

    newyorkin 1 ton status

    Joined:
    May 8, 2001
    Posts:
    16,555
    Likes Received:
    157
    Location:
    Los Estados Unitos
    I agree with triaged, and add that it would probably be more trouble than it's worth to do. There's other reasons not to, though. The pump is cooled by the fuel it's submersed in. When I used to run my tank to near empty a lot, I used to burn through fuel pumps more often (try changing a few in an '88 Camaro, where the tank is above the suspension, the exhaust, the diff)...
    I'd think it would also probably be really difficult to get a good seal at either the pickup or output of the pump, or enough of a good seal to mount externally. They're typically sealed plastic-ended units, so I doubt you could change the input enough to put a hose or pipe on.
    I think an aftermarket manufactured external pump is cheaper anyway. You might be better off putting that in if you're looking to do this for easy pump replacement.

    Bummer I'm not home, I'd get you a picture of one. I have a dozen in my basement that I picked up from a junkyard when my camaro's went, and then my old K5's.


    Ratch
    **<A target="_blank" HREF=http://k5.8m.com>http://k5.8m.com</A> What more is there to life?**
     
  5. 90K5

    90K5 1/2 ton status

    Joined:
    Jun 1, 2000
    Posts:
    3,719
    Likes Received:
    0
    Location:
    Lubbock, TX
    The GM in tank pumps are a lot better than the external ones. Most of them last about 150K before they need to be replaced...the external ones seem to go out all the time. When mine breaks, I'm just replacing it, and it should be good for another 150K or so...just my $.02

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  6. Cavalry

    Cavalry 1/2 ton status

    Joined:
    Oct 1, 2000
    Posts:
    978
    Likes Received:
    0
    Location:
    upstate NY(although I cant figure out why)
    I went to Napa today and looked at a intank pump.... looks like pretty much an no go on converting it to external. Here is why I would like to do it... I just put in a new tank, sender, etc. Now I am converting to TBI and need a fuel pump. As you guys probably know the tanks are different. I priced out out from Turbo City @ $140. ouch! Its really going to blow when that goes and I'm stuck where ever for a week while a replacement gets here. I have a lead on a junk yard tank from a 87, but that just means I have a 15 year old tank/pump in my rig and a brand new one in my garage.

    "There is a fine line between hobby and mental illness"
    Luke
    84 K5
     
  7. Executioner

    Executioner 1/2 ton status

    Joined:
    Feb 22, 2000
    Posts:
    1,530
    Likes Received:
    0
    Location:
    Temp. Ft. Walton Beach Fl. home=Tucson, Az.
    There is a F.I. pump expert out here, I don't rembember them, but they can reccomend, a good pump to mount to
    the frame, near the tank(externail). It can be replaced on the trail with a cheap spare to get you home.
    If it's for a system that uses 12-17psi. it can also be used for the Holley Pro-Jection as well !
    Hope they will see this post.
     
  8. elkboy

    elkboy 1/2 ton status

    Joined:
    Aug 18, 2000
    Posts:
    293
    Likes Received:
    0
    Location:
    Hillsboro Oregon
    Holly make a 15 PSI inline pump for TBI marine engines for about 140.00 . It looks about the same as the one that comes with the Holly TBI kit, but is marine rated. You should be able to use a pickup/senser unit from a late carberated engine and change it over.

    <font color=red> Elkboy </font color=red> 82 K5 fuel injected H.O.305, TH350/205, 14bolt/10bolt and 39.5 TSL's.
     
  9. pcorssmit

    pcorssmit 1/2 ton status

    Joined:
    Jan 2, 2001
    Posts:
    1,346
    Likes Received:
    0
    Location:
    Denver, CO
    If you're too cheap to get the correct FI tank, just modify the sender you have now to accept the in-tank pump and a return line (if it doesn't have one). The only difference in the fuel tanks is the baffling in the bottom, a problem you will still have if you use the current tank with an external pump. Just make sure you keep the gas above empty and you'll be fine, I have a couple friends with Jeeps running Pro-jection with stock Chevy TBI pumps that have done this, we also did it on my Brother's '70 K5. However, since the correct tank is available, I'd do it that way. Nothing wrong with a junkyard tank as long as it's in good shape, just put in a new fuel pump with the tank. Thats what I did when I converted to TBI.

    Pete

    '83 K5, 350 TBI (ex 6.2), 700R4, NP208, Dana 60/14 bolt, 4.56s, Detroits, 3" lift, 15-39.5x15 TSLs
    '97 Dodge 2500 4x4 CC LB Sport, Cummins 5 spd
     

Share This Page