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  1. #1

    Default what could cause this???

    I have a 91 z71. Whenever I start it up it cuts off on me. Kinda like its choking down. I have to press the gas for about 15 seconds then it runs and idles like its new! It will only do this if it sits for more than a few hours. If I go into someplace and spend about 30 minutes and come back out it starts up without any problems. What could be causing this?

  2. #2


    That is pretty weird. What comes to mind for me is maybe a fuel line is leaking and your losing pressure at start up but when you pump gas back into the fuel system its fine and when driving its a small enough crack it doesn't affect fuel flow. I may be wrong.

    2006 Duramax LBZ
    Edge Evo
    4'' Diamond eye to 6'' tip
    16'' ion alloy, 33'' fierce attitudes
    Lots of work left to do!

  3. #3


    go get a fuel pressure test and see how it goes if nothing then check and clean your carb

  4. #4


    sounds like a fuel pressure regulator to me.

  5. #5
    murdog94's Avatar
    Join Date
    Feb 2008
    Cloquet, Minnesota, United States
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    Quote Originally Posted by ScubaSteveo View Post
    sounds like a fuel pressure regulator to me.
    Also just so you know Rd3n3ck the 1987 up models came with EFI, and Throttle body with the built in fuel pressure regulator. No carbs to tune anymore on them. Not to be rude just letting you know since i thought they were carbed as well before i got one.


    1997 Chevy S-10 Blazer 4X4 with 330K miles and counting (Hunting rig).

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    "Hold it to the floor till you see God.... Then Brake!!!!"

  6. #6


    no no its cool im used to carbs and gettin used to thorttle

  7. #7


    rebuildit it, put new TPS on it and its still actin up. You can have the throttle wide open in park but you put it in gear it wont step up

  8. #8
    Sr. Mechanic Ethan's Avatar
    Join Date
    Sep 2009
    Cedar Park, TX


    Haha, my truck was doing the same thing, cleaned it and it fixed it, but the EGR valve was stuck open, so it would pump EGR gas into the throttle body during start up and choke it out. Try replacing your EGR valve and cleaning all your EGR lines.
    1994 Chevy Silverado 1500 Ext Cab 350 cuin TBI in dark Chevy blue
    160,000+ miles
    Original paint
    Original interior
    Original engine and tranny
    wrecked twice stolen once
    Diamond Plate bed rails
    Power windows
    Original Alloy wheels
    Original fancy smancy cup holder
    Tow package
    Original plastic bed liner
    K&N Cone Air Intake
    Dual MagnaFlow exhaust(not true dual) with chrome tips
    MSD Street Fire Performance Ignition coil

  9. #9
    Master Mechanic daddytech's Avatar
    Join Date
    Mar 2008
    Portland TN


    Seafoam always worked well for me, i take the main vacuum line out of the power brake booster let it suck all the seafoam from the can and lightly rev till the smoke stops and then i am good to go, fill the tank with gas then put another can in there and my tahoe stays running like a champ for a while after that. not a suggestion but that's what i do

  10. #10


    Dunno if it applies here, but one possible cause could be weak battery. My Caddy had a similar problem and that went away when new battery went in.
    Does it crank ok?


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