I know what it isn't

Discussion in 'Chevy Blazer Forum (GMC Jimmy)' started by D town, Mar 6, 2014.

  1. D town

    D town New Member

    Still having acceleration problems and rough start. Idle is a little rough. New fuel phinp, filter, clean K & N, new electric components. I think I will change all the oxygen sensors, Anyone have O2 sensor problems? I also still have gurgle sound behind dash when i accelerate. Seperate issue prob.
  2. RayVoy

    RayVoy Active Member

    You might have old/worn out/lazy O2 sensors, but if the problem is there when the engine is started cold (after sitting all night) it isn't the O2 sensors.

    When the engine is cold, the O2 sensors are not used, The sensors need to be hot and the exhaust gases need to be hot before the O2 sensors work properly.

    And if the sensors were bad when the engine gets up to operating temps, the PCM would throw codes and light the Check Engine Light.

    Does "new electric components" mean spark related things.

    Vehicle info would help me here.
  3. D town

    D town New Member

    97 jimmy. New spark plugs, wires, ignition coil, dist. rotor and cap. New battery. Original sensors, 220000 MI
  4. RayVoy

    RayVoy Active Member

    If that was my old Envoy, I would say the throttle body was dirty. If you had a carburetor, I would say the carb was dirty. I don't know about the throttle body on your truck, it has fuel injection as part of the throttle body, maybe the injector is dirty or worn.
  5. D town

    D town New Member

    Just cleaned my throttle body. My next idea was also the injectors. I do use Lucas injector cleaner every oil change.
  6. the phantom

    the phantom New Member

    Check the fuel pressure with a gauge.. Even though its new they can be low on pressure and defective. I went through this with a 99 jimmy I had. Mine required 65 psi to start and 55 to run..put a pump in and same problem. put a gauge on it and the pressure was 48 psi.. returned it for another and waalaaa.. purred like a kitten. you can rent the gauges basically for free from advanced or autozone.
    They are a pain to pull out of the tank. but Ive done it 5 times so I had it down to about a half hour R&R.
  7. D town

    D town New Member

    Overdue for a cleaning

    Attached Files:

  8. the phantom

    the phantom New Member

    Thats not helping any.:shocked: Good find.. let us know if that was the issue.
  9. zuki82

    zuki82 New Member

    That much crud on the bottom of the TBI unit? I'm thinking the EGR valve is stuck open with some crud! Jimmy I had was the same way! Carbon would hold the valve open just a little and the truck run like crap!
  10. D town

    D town New Member

    I think i will take the cheap fuel pump back and try an OEM or an american made. Then, get into the recirc. Valve. Haven't heard that problem before thanks i will be replacing that.
  11. D town

    D town New Member

    Have any knowledge of quality fuel pumps?
  12. D town

    D town New Member

    What should the fuel pressure be on 97 Jimmy? Looks like Airtex, from autozone is going to be my decision for a oem pump. 277.00 w/ lifetime warranty
  13. the phantom

    the phantom New Member

    Autozone is where I was getting the bad pump from myself(I think it was an airtex and your price sounds right. But if they are offering lifetime warranty then I would tend to go that route.. when I was buying them they only came with a 90 day warranty. I cut the cost down by replacing just the pump inside the sending unit. But then after a couple of pumps and a couple years the gas gauge didnt want to work right.. I think in part from possibly bending the little float and wire trying to get it in and out of the tank so many times.

    this is the seller on Ebay I bought the AC Delco pumps from if your interested and can wait for it. http://www.ebay.com/usr/premium-fuel-injection-pumps
  14. D town

    D town New Member

    I relaced the motor inside the unit once. Ended up taking it back and getting the whole unit. Two different style pumps. The gauge went out on both the after market pumps i bought. I have delt with the fuel pumps for the past 2 years trying to save a few bucks. I am a pro at changing them now, but i am tired of messing around with it. Going to spend on an OEM. Hopefully the gas gauge will work for more than a year.
  15. edsmagichands

    edsmagichands New Member

    Specs are 62-66PSI BE ADVISED! a problem in the fuel pump circuit (excessive voltage drop) can, and frequently does cause low pressure and premature pump failure. ALWAYS TEST THE CIRCUIT BEFORE AND AFTER INSTALLING A NEW PUMP! especially with a history of repeated pump failures. a test light won't due, you need a meter to test for voltage drop.
  16. j cat

    j cat Active Member


    when the egr is 10 yrs old replace it .
  17. estrom

    estrom New Member

    Curious to know...did you figure out what the gurgle sound is behind the dash?
  18. D town

    D town New Member

    No. Going to replace the thermostat. Maybe a long shot, but cheap and easy. It opens. But maybe too slow. Smells like coolant every once in a while weather the air vents are on or not. Not getting my hopes up. I will definitely post a solution if found.
  19. bellaverde

    bellaverde New Member

    My '98 JImmy will start to hesitate on accel when all I have on the TB throat is brown lacquer...
  20. ChevyFan

    ChevyFan Administrator Staff Member

    Wow, did you use anything inside the engine like seafoam or rxp in your tank? I assume you cleaned that up.

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