94 K1500 Starting Issue

Discussion in 'Engine Performance + Maintenance' started by dave s, Nov 2, 2019.

Car Parts
  1. dave s

    dave s Newbie

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    Hi guys,
    I just recently got my old 94 back from my daughter and her husband after they moved on and got new vehicles. It's a 5.0 manual shift 4x4. It will not start unless I add just a tiny bit of pedal. Then it takes a couple tries, almost sounds like a carb motor that is flooded a bit when I do that. Without adding some pedal, it just cranks and cranks. Once it starts it runs just fine. I pressure washed everything under the hood and around tranny area today in preparation to replace clutch and have tranny repaired. Then it wouldn't start at all. Dried out cap, blew out every plug connection. No go. Gave it a shot of starting fluid and it fired right up and stayed running just fine. Is that a sure sign pumps bad? I have a couple pieces coming from CFM technologies I learned about on here. I bought a thing bolts between gas line and tbi you can put a gauge on to check pressure. And I got a kit to freshen up the tbi after go through and disassemble and clean it. Those parts won't be here till Tuesday or Wednesday. I searched for three days but have not found a definitive answer to this. I'm good getting a new fuel pump but just making sure there's not another sensor or something keeping it from starting.
     
  2. PlayingWithTBI

    PlayingWithTBI Desert Old Guy

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    It sure sounds like low fuel pressure. Could be weak pump, partially plugged filter, or bad pressure regulator. You're on the right track getting the pressure gauge, install it and see what you have, s/b 11 - 13PSI. GM says 9 - 13 is acceptable but, higher pressures help with starting. If pressure is low, pinch off the return line and see if it spikes higher with key on. If it does, it's your regulator. If not, pump and/or filter. Remove the filter and try to blow through it (I know YUCK).

    If you do replace the fuel pump get an AC Delco or Delfi pump AND filter, clean the ground contacts too. IMO it's easier to remove all the bed bolts except one on the passenger side (just loosen it), disconnect the tail light harness and the fillet neck. Then you can tilt the bed up and prop it with a 2X4.
     
  3. dave s

    dave s Newbie

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    Thanks for the help. I did put a new filter on first day I got it. Gas came out of it looked nice and clean. You say put the bed on a 2x4, does that mean on edge? Just the 3 1/2" will let me pull the pump out I'm guessing...
     
  4. PlayingWithTBI

    PlayingWithTBI Desert Old Guy

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    No, if you can lift the bed 18 - 24" cut a 2x4 that long and brace it up.
     
  5. evilunclegrimace

    evilunclegrimace Does not always play well with others

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    You can get the pump out with 9" of lift, I use a piece of 6X6 that is 3 feet long on top of the frame from the tire back with a 4X4 on top of that. That gives me enough room to pull the sender and rotate it up and out of the tank.
     
  6. dave s

    dave s Newbie

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    Ok, I got it now. I did my Dads a few years ago and we took the whole bed off because everything on his 2003 is nothing but rust! No rust under this truck, bolts should all come out good I'm hoping. Thanks for the info.
     
  7. dave s

    dave s Newbie

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    Well I bought a new clutch kit from Rock Auto. Drove truck to a friends shop, he does transmission rebuilds. I gave it a shot of starting fluid and it fires up immediately and ran fine the whole way there. I am going to order a new fuel pump while I'm waiting to get it back. I'm looking on Rock Auto to get a Delphi pump HP 1000. Reading more looks like I need a new strainer as well? I'm also seeing "with hi temp fuel sender" and without. My trucks a 94 with a 305 tbi motor, rcsb. I'm unsure about the hi temp thing. Well I see the pump and sender assembly at Advance Auto and looks to have strainer. Might be my best bet as its local.
     
    Last edited: Nov 10, 2019 at 8:02 PM
  8. Philhammerjr

    Philhammerjr Newbie

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    Maybe they are referring to the hot fuel module? If so those were only on the r/v series trucks. Not sure why that would affect which pump you need though. Iirc the Delphi pump came with 2 size rubber things that the pump sat in. Only one actually fit my sending unit. It also came with a connector in case the one on the sending unit didn't fit the pump. Imo it would be better to make sure the pump is in fact the issue before going through the trouble to replace it. It could be fine and just the regulator is the issue
     
  9. thinger2

    thinger2 Newbie

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  10. thinger2

    thinger2 Newbie

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    Get a new lock ring for the fuel pump . 5 bucks at NAPA. The old one will likely be pretty crusty and beat up by the time you get it off and not worth the fight to get it back on. The top of the pump is sealed with some kind of thick grease. I used wax from a toilet bowl ring and it works.
    You can lay a section of 2x4 across the spring and set your factory screw Jack on top of it to tilt the bed. The Jack will sit between the frame and the tire on top of the board.
    If you take all of the bed bolts out, use a couple of ratchet straps from the passenger side of the bed to the drivers side frame.
    When you tilt if far enough the bed will slide sideways and dent the back of the cab and the rear corner of the bed.
    And make sure it's rock solid in place before ya stick your head under it.
    It ain't fun but it beats the he'll out of dropping the tank
     

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