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.

Is it really my fuel pump?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Boss, Oct 9, 2001.

  1. Boss

    Boss 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    2,550
    Likes Received:
    0
    Location:
    Maryland
    Ok, during Dixie run, I had some issues with the truck. It would cut off a bunch of times. Most of the time it would fire right back up and go, but then cut off later. Sometimes we had to wait several minutes before it would fire back up.

    Well, today, driving to work, the truck cut off on my 4 times total. Everytime was when I was making a wide slow LEFT turn. Like on a huge intersection, or on the "circle" intersection. It never cut off when I made a right turn or a quick left turn like in a parking lot. It's does fire back up immediately though. I would kick the truck in Neutral while it's still rolling and crank her back up and go. (I'm getting good at that now). It's scary b/c cars are riding my tail really close etc, when it all of the sudden cuts off. It's really annoying. I'm getting the Walbro fuel pump soon, but won't have time to put it in till later. But is this really a fuel pump problem??? No check engine light either (until the motor cuts off ofcourse)
    Boss

    Pic of my truck Before N' After
    <a target="_blank" href=http://coloradok5.com/gallery/BeforeNAfter>http://coloradok5.com/gallery/BeforeNAfter</a>
     
  2. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    Hmmmmmmmmmmmmmmm. Look for some simple stuff first. Check the connections at the distributor. Check wires running back to the pump for trail damage or getting up against the exhaust. Ground straps, Stupid stuff. Maybe the body lift is pulling on some wires or pinching them and the extra shift is pulling on a harness. Check the ground strap in in the cap for the Coil and make sure you got a tight connection.
    It's totaly possible something got knocked loose on the trail and you have a bad connection.

    I don't need no damn shop manual, I got a pornographic memory.
    <a target="_blank" href=http://communities.msn.com/OffroadK5s>communities.msn.com/OffroadK5s</a>
    75 Jimmy, Dollar
    Grim-Reaper
     
  3. Pugsley

    Pugsley 1/2 ton status

    Joined:
    Jan 16, 2001
    Posts:
    3,556
    Likes Received:
    0
    Location:
    Tucson, Arizona
    That's definitely what it sounds like - either the pump itself, or an intermittent connector in the wiring.

    Of the 5 toughest dogs in the neighborhood, my cat's ranked #3
    <a target="_blank" href=http://pugsley.alloffroad.com>pugsley.alloffroad.com</a>
     
  4. Leadfoot

    Leadfoot 1/2 ton status Premium Member

    Joined:
    Nov 28, 2000
    Posts:
    3,112
    Likes Received:
    1
    Location:
    Western Massachusetts
    Grim is right check the simple things. It sounds like it could be an electrical issue as much as fuel. Also I have seen vehicles that intermittently vapor lock. Check any and all fuel filters for debris. Also might not be a bad idea to throw a bottle of dry gas in during the next fill up. Clean the choke assembly and air cleaner. These might not solve the problem, but they won't hurt. Also are you running a mechanical or electric fuel pump. If electric is it tank or frame mounted?

    See my rig at <a target="_blank" href=http://coloradok5.com/gallery/Leadfoot>http://coloradok5.com/gallery/Leadfoot</a>
     
  5. Boss

    Boss 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    2,550
    Likes Received:
    0
    Location:
    Maryland
    I'm running the electric. It's in the tank. I will check all those mentioned above. Thanks for the suggestions. I didn't even think of this being an electrical problem [​IMG]
    Boss

    Pic of my truck Before N' After
    <a target="_blank" href=http://coloradok5.com/gallery/BeforeNAfter>http://coloradok5.com/gallery/BeforeNAfter</a>
     
  6. Depdog

    Depdog 1/2 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    1,657
    Likes Received:
    0
    Location:
    Georgia
    If its an electrical problem, its probably something simple. Maybe a wire grounding out when you turn that direction, or a plug getting pulled out of connection.

    With all the waterbars and rocks on Trail 4,5, its totally possible that something shook loose, I know my butt is just now recovering from the jarring!

    Depdog

    <font color=blue>Weenie K5, little mods' Small Tires!</font color=blue>

    <a target="_blank" href=http://depdogsk5.coloradok5.com>depdogsk5.coloradok5.com</a>
     
  7. Stoopalini

    Stoopalini 1/2 ton status

    Joined:
    Oct 17, 2000
    Posts:
    999
    Likes Received:
    0
    Location:
    Austin, Texas
    Hey Boss! Wassup?

    My '88 Jimmy did the same thing. I replaced the fuel pump and it solved some of my issues, but it would still die out on me intermittently.

    Do you have headers? I ended up taking the headers off and wrapping them because I had a fuel line that came up almost right on top of the passengers side header. After I wrapped them up, the problem went away.

    The fuel line was vapor locking because of the heat generated by the header, and the fuel line being so close to it.

    Just another thing to check......

    Good luck,

    Thomas.

    -- '84 K5 Blazer --
    <a target="_blank" href=http://stoopalini.off-road.ws/blazer>My Blazer Site</a>
     
  8. BIGRIG

    BIGRIG 1/2 ton status

    Joined:
    Feb 29, 2000
    Posts:
    488
    Likes Received:
    0
    Location:
    Independence, MO
    electric pumps don't really go half, either they run or they dont. check the filter first...that's what it sounds like and then move to the wiring. If you have to pull the pump assembly and make sure the pick-up is not getting stuck and is getting enough fuel.

    Chris


    MY DRINKING TEAM HAS A FOUR WHEELING PROBLEM![​IMG]
     
  9. fright89

    fright89 1/2 ton status

    Joined:
    Sep 27, 2001
    Posts:
    279
    Likes Received:
    0
    Location:
    boston
    look at the wire harness along the frame thats what killed mine left me stranded about 4 feet away from rising waters on the beach during a wicked snow storm.big bucks to get towed off the beach in the midle of the night. also took the fuel pump out of the tank and mounted a malory on the frame it is cool because you can here it hum when its working.
     
  10. CaptCrunch

    CaptCrunch 1/2 ton status

    Joined:
    Feb 2, 2001
    Posts:
    3,596
    Likes Received:
    1
    Location:
    Minnesota
    I would check like Grim said... does the truck sputter and/or bog before it dies or just cuts out? If you can't find anything try the tps. It sounds stupid but I have had 2 Blazers come in w/ a die whule turning left and intermitant stalling and low and behold the tps was at fault on both of them. Obviously it could be coincidence, but it is worth a shot if all else fails. I usually recomend scoping the voltage, but you probably don't have access to one so you might just pick up a new sensor and use the try and see method if all else fails and keep the receipt [​IMG]

    -Mikey
    1987 Chevy K5 Blazer- 350 TBI
    <a target="_blank" href=http://coloradok5.com/gallery/captcrunch>http://coloradok5.com/gallery/captcrunch</a>
     
  11. bigk

    bigk 1/2 ton status

    Joined:
    Jun 13, 2001
    Posts:
    358
    Likes Received:
    0
    Location:
    Mendon Illinois
    I've wondered about an inline pump. What did you do with the pump in the tank, just leave it there or can it just come out? Thanks.

    Karl
    Temporarily Unemployed Underwear Model
    87 3/4 ton
     
  12. zakk

    zakk 1/2 ton status

    Joined:
    Sep 21, 2001
    Posts:
    4,762
    Likes Received:
    0
    Location:
    San Jose CA
    had a simular problem, only the '77 was trying to die at highway speeds. i replaced everything and it ended up being the distributor...so i would check there...just my .02

    -Zakk
    '77 K5 SB 400 TH350 NP203 p/t 6" Lift D60 14BFF 4.10's 36"Wrangler II's

    [​IMG] MOAB 2002 OR BUST!! [​IMG]
     
  13. fright89

    fright89 1/2 ton status

    Joined:
    Sep 27, 2001
    Posts:
    279
    Likes Received:
    0
    Location:
    boston
    took the old pump out of the tank and used the wire from it for the new one. it is a malory i think it is a 6040fi i can find out for you if need be. kinda exspensive but works real nice no regulater needed. got some fittings at homedepot and did the plumbing wasnot to bad. much better stsrts and idol. the old one in the tank was mounted good and did not seem like it was going to fall off in there but i have heard stories of it happening. out of the tank is also field replaceable. let me know if you want to check the number on the malory
     
  14. fright89

    fright89 1/2 ton status

    Joined:
    Sep 27, 2001
    Posts:
    279
    Likes Received:
    0
    Location:
    boston
    also put an in line filter before the pump and replaced the one after. had to put an extension line in the tank the length of the old pump so it woud suck the gas out down to the bottom or at least almost
     

Share This Page