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.

PLEASE help im stuck

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by jms0945, Feb 20, 2002.

  1. jms0945

    jms0945 Registered Member

    Joined:
    Aug 22, 2001
    Posts:
    64
    Likes Received:
    0
    Location:
    Huntsville, Alabama
    Ok here goes my friends, this may end up being a novel, but I’m completely lost on this one. I have a 1988 K-5, of course in 88 they had fuel injection, but the guy that had the truck before me took that off and put a carb on it. He also put a TH-400 tranny in it. As far as I can tell everything else is stock. Here is what I have done: pulled the 350 had it bored .030 over, put a cam in it with a duration of 292 intake and exhaust lift of 480 intake and exhaust, put a renewed holley 600 on it, had the heads worked, it has hypoetectic flattop pistons in it, turned and polished the crank, high volume fuel pump, newer water pump, double roller timing chain. I may have forgotten something but that’s it for now. Here is my problem: set the motor in the truck, everything went together well, primed it made sure it had fuel cranked right up. But the thing WILL NOT idle, you hit the gas alittle and it comes back down and goes dead, here is what we have check or changed, first thing we thought was the jets, put 67’s in it didn’t work, totally rebuilt the carb didn’t work, when the fuel injection was taken off he put a fuel regulator on it so we put a gauge on it to see how much fuel pressure it was getting seemed that it wasn’t getting enough so we put a new electric pump on it, pump couldn’t keep up so we put a mechanical pump on it, seems to keep up ok, but still will not idle, we have changed distributors no change, checked SEVERAL times for vacuume leaks couldn’t find any, now this truck still has the original fuel tank with the orig. fuel pump and torque converter in it, I do not know a lot about converters so I’m open for suggestions, keeping in mind I have went way over budget with this project (so the wife says). The timing is good the plugs and plug wires are good just put cap, rotor and coil on it. so my problem is that i cant get the truck to idle good and when i hit the gas and run it up to about 3.5 grand it just comes back down and dies, has anyone had anything like this happend with thiers or knows if i need to change anything that has not been changed? If anyone would like to talk about this off list I would be more than happy to do so, I just need some help

    Thanks in advance
    MikeMike
     
  2. muddin4fun

    muddin4fun 3/4 ton status

    Joined:
    Feb 19, 2001
    Posts:
    5,644
    Likes Received:
    0
    Location:
    N Texas
    If I read correctly, you have two fuel pumps on it??

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

    wasn’t getting enough so we put a new electric pump on it, pump couldn’t keep up so we put a mechanical pump on it

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

    now this truck still has the original fuel tank with the orig. fuel pump and torque converter in it,

    <hr></blockquote>

    How did you lash the valves? Any backfiring? How did you check the timing if it doesn't idle?

    "Out in Luckenbach Texas, there ain't nobody feelin no pain" Waylon Jennings 1937-2002

    <a target="_blank" href=http://www.bluefox.tv/~lara>My Wonderful Site</a>
     
  3. jms0945

    jms0945 Registered Member

    Joined:
    Aug 22, 2001
    Posts:
    64
    Likes Received:
    0
    Location:
    Huntsville, Alabama
    yes it still has the origional electric fuel pump in the tank, ive unplugged it and im using a mechanical pump. I was told that if i just unplugged the origional pump that it would not restrict the new one, i also forgot to say that the fuel return line is still running from the front of the motor to the tank, it has just been plugged off. as far as back firing it did alittle until we adjusted the valves the best we could at the lowest we could get it to idle which is about 950-1050rpm and the same goes with the timing, it will idle down as far as about 800rpm but as soon as you tach it up to about 3000rpm it drops back down and dies.
     
  4. Stoopalini

    Stoopalini 1/2 ton status

    Joined:
    Oct 17, 2000
    Posts:
    999
    Likes Received:
    0
    Location:
    Austin, Texas
    I'm just shooting in the dark here, but have you put a vaccuum guage on it yet? Maybe your vaccuum is not high enough to maintain an idle?
    I had a similar problem with a 305 when I switched to 1.6 roller rockers, but this was a FI motor, so the computer compensated for it, although the idle is still a little wacky.

    Just something to consider .........

    Good luck, hope you get it resolved soon.

    Thomas.

    -- '84 1-Ton Blazer --
    When the goin' gets tough,
    the tough go 1-Ton [​IMG]
     
  5. Mobile_Mechanic

    Mobile_Mechanic Registered Member

    Joined:
    Jul 17, 2001
    Posts:
    88
    Likes Received:
    0
    Location:
    Phillipsburg, NJ
    Definitely sounds like a fuel problem. If you can run it to 3000 with no sputtering, then it dies, it sounds like you are starving for fuel. When it hits 3000, are you holding the throttle open or releasing it? Try leaving the electric fuel pump plugged in.

    '84 K30, 6" suspension, 3"body, 350, 350, NP205
    D60, 14 FF W/Detroit, 4.56 Gears, 35" Ground Hawgs
     
  6. txbartman

    txbartman 1/2 ton status

    Joined:
    Jun 1, 2001
    Posts:
    1,975
    Likes Received:
    0
    Location:
    Plano, TX
    When we fired my crate I had a similra problem. Check this out, had to do with my canister! There was a vaccuum line that was connected through the canister. With the line simply plugged, it ran smooth as silk and idled beautifully. When I ran it through the canister as it was supposed to, it chugged, gurgled, idled rough, and would die. Until I figure out the problem, I have simply capped the line.

    Go through all the vaccuum connections and plug them. You could have a devide attached to a vaccuum line not functioning correctly. I never would have thought my canister was causing my problem.

    Brian
    Check out <a target="_blank" href=http://tx85gmcguy.alloffroad.com>My Jimmy</a> with all her projects!
     
  7. jms0945

    jms0945 Registered Member

    Joined:
    Aug 22, 2001
    Posts:
    64
    Likes Received:
    0
    Location:
    Huntsville, Alabama
    I havnt tried that yet, we did check to see if all of them were hooked up and all, i also have not put a vacuum guage on it yet.
     
  8. jms0945

    jms0945 Registered Member

    Joined:
    Aug 22, 2001
    Posts:
    64
    Likes Received:
    0
    Location:
    Huntsville, Alabama
    I have also been told that my torque converter may need to be replaced for one that stalls until about 2000rpm
    but im not sure if the converter would make a differance if the truck is in park or if it only kicks in when you put it into drive.
     
  9. txbartman

    txbartman 1/2 ton status

    Joined:
    Jun 1, 2001
    Posts:
    1,975
    Likes Received:
    0
    Location:
    Plano, TX
    Just because they are hooked up doesn't mean a device may not be leaking. Try to take as many variables out of the question first.

    Brian
    Check out <a target="_blank" href=http://tx85gmcguy.alloffroad.com>My Jimmy</a> with all her projects!
     
  10. Mobile_Mechanic

    Mobile_Mechanic Registered Member

    Joined:
    Jul 17, 2001
    Posts:
    88
    Likes Received:
    0
    Location:
    Phillipsburg, NJ
    I think the torque convertor has nothing to do with the stalling condition. The TC only comes in to play when you are in gear. You want to match the stall speed of the TC with the power band of the engine. Keep it on the low side since you don't want to scream your engine while in the rocks crawling. If you are in the mud more often then go a little higher in the rpm band.

    '84 K30, 6" suspension, 3"body, 350, 350, NP205
    D60, 14 FF W/Detroit, 4.56 Gears, 35" Ground Hawgs
     
  11. jms0945

    jms0945 Registered Member

    Joined:
    Aug 22, 2001
    Posts:
    64
    Likes Received:
    0
    Location:
    Huntsville, Alabama
    ok we went through the vacuumes and still doing it, changed the plugs, no change. The vacuume advance was sticking so i replaced it which made it rev better but still goes dead when it comes back down to idle..
     
  12. jms0945

    jms0945 Registered Member

    Joined:
    Aug 22, 2001
    Posts:
    64
    Likes Received:
    0
    Location:
    Huntsville, Alabama
    Ok ive been FINALLY driving my truck since last night, still the only problem (other than my big 10mpg) is that when in park, i'll tach up the motor up to about 3000-3500rpm, when it comes back down to idle, it goes dead. I've looked and looked for vacuum leaks and plugged all of them off that i do not need, checked fuel pressure, everything i can think of..
    Just dont know what to do now, she runs wonderful, i can sit in drive and gas it, and she wont go dead.......... just in park or neutral......
     
  13. jimmyjack

    jimmyjack 1/2 ton status

    Joined:
    May 11, 2000
    Posts:
    2,290
    Likes Received:
    0
    Location:
    Tucson Az
    Maybe the valves are too tight?

    That jeep thing? Yah I understand it....... Like my Blazer? <a target="_blank" href=http://community.webshots.com/user/blazerk5>http://community.webshots.com/user/blazerk5</a>
    Jim
     

Share This Page