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hesitation/bucking/uneven idle/loss of power '97 Explorer

Discussion in 'Under the Hood' started by bal15, December 5, 2004.

^^Searches ExplorerForum.com^^
  1. bal15

    bal15 New Member

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    This is my first time posting here. I have a 97 Explorer that I recently purchased for my son. It recently started to run unevenly, hesitate, and have reduced power. It is a 6 cylinder, has 98k miles. I bought it when it had 90k on it, and it ran flawlessly until recently. Upon noticing this (I rarely drive the vehicle) I changed the spark plugs, spark plug wires, pvc valve, and fuel filter, yet it still hasn't corrected the problem.
    Any suggestions?
     
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  3. Blee1099

    Blee1099 Evil Asian EF Vendor Moderator Emeritus

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    Clean the MAF sensor & either clean or replace the IAC.. I vote for replacing the IAC.. More than likely the one in it is beyond cleaning at this point.
     
  4. TPLYNCH

    TPLYNCH Well-Known Member

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    Check the vacuum lines for leaks as well.
     
  5. bal15

    bal15 New Member

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    Thanks. Any details on how to clean the MAF sensoor. I found a thread on the IAC, but not the MAF.
     
  6. TPLYNCH

    TPLYNCH Well-Known Member

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  7. bal15

    bal15 New Member

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    Okay. I finally got to it. I cleaned the MAF and the IAC. The problem is still there, especially at low rpms. And in addition, I have a humming sound which I didn't have before.
    Now what do I do?
    I originally bought a replacement IAC from Advance Auto parts, brought it home and it didn't match. I brought it back and they couldn't match it with the old one.
    Confused!!
     
  8. 410Fortune

    410Fortune Mud Season Staff Member Moderator

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    there were two V6's offered in 97, the pushrod OHV and the SOHC, both are 4.0L

    Which one do you have?
    Stick or auto?
    is the check engine light on, or does it come on?
    Sounds to me like a fuel problem, either filter, pressure regulator, clogged cat, or bad 02 sensor.

    Also you did reset the battery after cleaning the intake and MAS correct?

    We need to know which engine you have, also what transmission, and if the CEL is illuminated.
     
  9. bal15

    bal15 New Member

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    I have the SOHC, automatic. The engine light has never come on. I have changed the fuel filter, spark plugs, spark plug wires and pcv valve. I did reset the battery.
    Thanks for your help. I ordered a new IAC from Napa, it will be in tomorrow morning, hopefully that is the answer.
    What do you think?
     
  10. 410Fortune

    410Fortune Mud Season Staff Member Moderator

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    I dont think the idle air control valve will have anything to do with your surging and loss of power while driving.
    Have the fuel pressure checked and test for vacuum leaks.
    My $$$ is on the fuel system as stated above.
    |
    You can listen to the fuel pump and see if it is making any strange sounds
    You may also have a clogged cat?
    Witht he 97 SOHC you want to find out if the Ford service bulletins have been performed on this truck (leaking intakes, timing chain tensioner)
     
  11. BuffaloXplorer

    BuffaloXplorer The X had to go!

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    On my '96 OHV, i recently developed a similar situation. I cleaned the throttle body (carb cleaner, toothbrush, box-o-rags) and it cleared right up.
     
  12. bal15

    bal15 New Member

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    I got the new IAC and installed it, still the same symptoms. How do I check the fuel pressure and test for vacuum leaks?
    Where is the fuel pump to listen to?
    How would I know if it is a clogged cat (I am assuming catalytic converter)?
    Where and how do you clean the throttle body?
     
  13. 410Fortune

    410Fortune Mud Season Staff Member Moderator

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    Okay, half of these questions if not all can be answered using the search button.

    The throttle body is also not your problem, though it never hurts to clean it.
    To clean the TB unbolt it, disconnect the hoses and cables, clean it with TB cleaner, simple. Careful not to damage the gasket and you can re-use it.

    The fuel pressue is tested at the fuel rail, there is a schrader valve there, you need a fuel pressure gage and also the specs for your truck at idle.

    The fuel pump is mounted inside the gas tank, you can listen to it by getting down under there and have somebody turn the key to "ON", it will come on for a few seconds each time. If it is making a gurgling noise it may be bad.
    If you have too much fuel pressure and no CEL then it is likely your pressure regulator is bad, normally if it runs rich enough to cause the sysmptoms you describe it is either a bad regulator or 02 sensor, but the 02 sensor will normally set the CEL.

    Again you need to find out if the SOHC service bulletins have been performed on your truck, any ford dealer or CARfax should be able to tell you.........
     
  14. BuffaloXplorer

    BuffaloXplorer The X had to go!

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    Also, invest $15-$20 and buy a Haynes manual @ almost any autoparts store - most of the tests can be gotten from that.
     
  15. bal15

    bal15 New Member

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    I have had the 97 Explorer in and out of the shop for the last month. The mechanic has run test after test and has now told me that he thinks the problem is that the timing jumped (whatever that means) and will costs thousands of dollars to repair.
    He says the compression is 120 and should be 150-180, and he can only track it back to being the timing having jumped, which is unusal but he can't find anything else it can be. And resetting the timing requires pulling the engine. Does this sound right to anyone?
    The things he tested were the fuel system, catalytic converter, that I know of. I am at a loss and I'm starting to think it's time to get rid of this truck. Is it worth putting any more money into it?
    Help!!!! Please!!!!
     
  16. Skibug

    Skibug Active Member

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    To have the timing jump is not likely. Take it to someone else and get a second opinion. Basically that mechanic is just at a lost for what it could be and is just guessing now.
     
  17. MazdaGreg

    MazdaGreg Active Member

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    Timing Jumping does not sound right to me either. Your compression would be all over the place if it had jumped. Some cylinders would be dead, some would have ok compression, it all depends on the timing on the cams....

    Get a second opinion.
     
  18. TPLYNCH

    TPLYNCH Well-Known Member

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    Do you know if the 00M12 and 01M01 work (intake manifold o-rings, timing chain cassettes and camshaft tensioners extended warranty) was performed on the truck? If you are still under 100K, you should still be eligible for the 01M01. Call Ford, and with the VIN # they should be able to tell you. That would handle a big chunk of the expense.
     
  19. monkeydude3

    monkeydude3 Active Member

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    my idea would be the fuel pump... check the fuel pressure, ford explorer pumps are notorious for taking a big dump... like mine did two years ago! that was fun, ran like crap for a while and eventually did not run. Look into your fuel pressure, fuel pressure regulator and fuel pump! see ya

    George
     
  20. bal15

    bal15 New Member

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    I have taken the Explorer to another mechanic, a Ford dealer. They have come up with a similar diagnosis. It is a mechanical problem, cam shaft, timing. They suggested it may be better to replace the motor. Is it worth it? $3000 or so for a used motor.
     
  21. TPLYNCH

    TPLYNCH Well-Known Member

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    Ford should cover most of the cost as the parts that caused the failure are under extended warranty. Did you buy it from a used car dealer? If yes, go back to them to recoup costs. If the tensioners or timing chain cassettes grenaded, lots of plastic pieces are floating around your engine, plugging up oil passages. Replacing the motor is the way to go.
     






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