Page 1 of 2 12 LastLast
Results 1 to 20 of 33

Thread: Mechanics..Help Idle problem 1995 mercury Mystique 2.0L

  1. #1
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996

    Mechanics..Help Idle problem 1995 mercury Mystique 2.0L

    Having an idle problem only when vehicle is in gear. Vehicle runs great except for expected knock at 190K... When I come to a stop it wants to die. If I sit in a parking lot put it in drive with my foot on the brake, eventually usually 15-30 seconds the idle will drop from normal 750-850 rpm to 500 or less all of a sudden and struggle to run, sometimes it will stay running, other times will die.

    I bought a new idle control valve after searching similar symptoms, had it installed after looking at what a bitch it was going to be, still have the problem. Like I said the engine runs great except for when I stop at an intersection, ect.

    Any ideas on where to go next? Recently replaced timing belt and had the cam timing checked, I replaced plugs and wires.

    Is there anything with the transaxle that could be locking up causing the sudden decrease in idle? Vehicle shakes like crazy when it gets to 500rpm or less.

  2. #2
    Senior Member Helen Keller's Avatar

    Join Date
    Aug 2010
    Location
    Lookin for da Chewin'
    Posts
    5,300
    SOunds like a bad or dirty throttle position sensor.
    I KILL WHITE PEOPLES LIKE YOU

  3. #3
    Member

    Join Date
    Jan 2012
    Location
    Decatur, AL
    Posts
    75
    That is something that you can spend a lot of money chasing various sensors. I would take it to the parts store with you, and let them plug it in the computer for you. Most of them will do that for free.

  4. #4
    Administrator Krupski's Avatar

    Join Date
    Oct 2001
    Location
    ┌П┐(◣_◢)┌П┐
    Posts
    10,876
    Quote Originally Posted by 1 Patriot-of-many View Post
    Having an idle problem only when vehicle is in gear.
    I had the same problem with my high mileage Honda Accord. There was so much blowby that when the EGR valve opened, it was too much and it killed (or almost killed) the engine.

    Try disconnecting the vacuum hose from your EGR valve and see if that makes the problem go away. Chances are you will get a "check engine" light because the computer will see a "egr commanded but did not respond" error.

    If that's the problem, remove the EGR valve and make a new gasket for it (without a hole for the gasses!) and put it back on. The valve will cycle, the computer will be happy and there will be no EGR to screw up the running of the engine.

    If it works and you DON'T get a check engine light, then just plug the vacuum hose and stick it back on the EGR...
    Gentlemen may prefer Blondes, but Real Men prefer Redheads!

  5. #5
    when you replaced the IAC did you clean the throttle plate and air passages in the throttle body? Krupski has a point about the EGR but the problem is likely the DPFE sensor . . . while checking it out look for cracks in the vacuum hoses too

  6. #6
    Senior Member Kadmos's Avatar

    Join Date
    Jul 2010
    Location
    STL
    Posts
    6,871
    Quote Originally Posted by 1 Patriot-of-many View Post
    Is there anything with the transaxle that could be locking up causing the sudden decrease in idle? Vehicle shakes like crazy when it gets to 500rpm or less.
    Yes.

    I would start by checking the fluid level. Make sure the engine is warm, pass through all the gears and then check it in neutral with engine running (just to be 100% clear we are talking about an automatic..yes?)

    If it's low enough it will do exactly what you described. You may have a leak, that leak might be spitting fluid onto the torque convertor.

    If any of this is true you might, considering the age and miles of the car, want to start by adding Lucas transmission fix in there and see how it does. It's a really thick additive that can stop leaks (internal and external) and really smooth things up, and quiet things down.

  7. #7
    Im thinking transmission too.I had one that did that after it got hot.It was some switch or valve in the trans but for the life of me forgot which one.
    Not sure but I think it had something to do with the converter.
    After it started doing it you would have to cool it down otherwise it would quit as soon as you put it back in gear.
    Last edited by shotdown61; 06-27-2012 at 12:07 PM.

  8. #8
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996
    Quote Originally Posted by GreenhawK View Post
    That is something that you can spend a lot of money chasing various sensors. I would take it to the parts store with you, and let them plug it in the computer for you. Most of them will do that for free.
    It's not throwing any codes/no check engine light.

  9. #9
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996
    Quote Originally Posted by Krupski View Post
    I had the same problem with my high mileage Honda Accord. There was so much blowby that when the EGR valve opened, it was too much and it killed (or almost killed) the engine.

    Try disconnecting the vacuum hose from your EGR valve and see if that makes the problem go away. Chances are you will get a "check engine" light because the computer will see a "egr commanded but did not respond" error.

    If that's the problem, remove the EGR valve and make a new gasket for it (without a hole for the gasses!) and put it back on. The valve will cycle, the computer will be happy and there will be no EGR to screw up the running of the engine.

    If it works and you DON'T get a check engine light, then just plug the vacuum hose and stick it back on the EGR...
    I will try that second.

  10. #10
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996
    Quote Originally Posted by samiam View Post
    when you replaced the IAC did you clean the throttle plate and air passages in the throttle body? Krupski has a point about the EGR but the problem is likely the DPFE sensor . . . while checking it out look for cracks in the vacuum hoses too
    I had the shop replace the Idle adjustment valve. I doubt it. I saw another online post to get CRC intake cleaner, run it at high idle and spray at least half a can into the throttle body, then disconnect battery for 5 minutes, reconnect and drive normally, So I think I'll start with the idea the passages are gunked up.

    What's a DPFE sensor? AHHH. google is my friend. Thanks. http://www.focushacks.com/mod/DPFE_S...GR_Information
    Last edited by 1 Patriot-of-many; 06-27-2012 at 03:13 PM.

  11. #11
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996
    Quote Originally Posted by Kadmos View Post
    Yes.

    I would start by checking the fluid level. Make sure the engine is warm, pass through all the gears and then check it in neutral with engine running (just to be 100% clear we are talking about an automatic..yes?)

    If it's low enough it will do exactly what you described. You may have a leak, that leak might be spitting fluid onto the torque convertor.

    If any of this is true you might, considering the age and miles of the car, want to start by adding Lucas transmission fix in there and see how it does. It's a really thick additive that can stop leaks (internal and external) and really smooth things up, and quiet things down.
    Idles fine in neutral and park. Only when in gear does this problem manifest itself. fluid levels are fine. Might throw some Lucas trans fix for the hell of it.
    Some good ideas here, thanks everyone, gives me a start before I drive my deuce over the car..... Been sinking money into this car lately, new tires, new front bearings, ball joints timing belt cam seals ect ect ect, I hate to toss it over an idle problem but hate to keep sinking more in it. But don't want a car payment either...Half a loaf of one.....
    Last edited by 1 Patriot-of-many; 06-27-2012 at 03:06 PM.

  12. #12
    Senior Member Kadmos's Avatar

    Join Date
    Jul 2010
    Location
    STL
    Posts
    6,871
    Quote Originally Posted by 1 Patriot-of-many View Post
    Idles fine in neutral and park. Only when in gear does this problem manifest itself. fluid levels are fine. Might throw some Lucas trans fix for the hell of it.
    Might take a month or two to lose half a quart, but yeah, same symptoms I had on my jeep and have seen in other cars. My jeep was dying like crazy. Lucas fixed it right up. But you might need a flush, filter, and fill first. It really sounds like a transmission issue.

  13. #13
    Team GunsNet Silver 07/2011 Sherman's Avatar

    Join Date
    Jul 2010
    Location
    North Texas
    Posts
    635
    Dynamite/with fuse and a lighter or blasting cap and battery. They were renamed Ford Mistake for a reason.

  14. #14
    idle air control may need reset some vehicles dont have to be reset some do take positive battery cable off for an hour to reset it it clears the computer. clean the mas air flow sensor if it has one.check fuel pressure should be 35-40 lbs.clean air filter or get a new one.if you think it may be a vacuum leak get a can of starting fluid and spray around all rubber vac lines while its running if it idles up check the line for cracks.

  15. #15
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996
    Quote Originally Posted by Kadmos View Post
    Might take a month or two to lose half a quart, but yeah, same symptoms I had on my jeep and have seen in other cars. My jeep was dying like crazy. Lucas fixed it right up. But you might need a flush, filter, and fill first. It really sounds like a transmission issue.
    I've had a recent flush and fill on the tranny, I got the lucas today on the way to work, will put it in in the next day or two. Thanks for the suggestion.

  16. #16
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996
    Quote Originally Posted by Sherman View Post
    Dynamite/with fuse and a lighter or blasting cap and battery. They were renamed Ford Mistake for a reason.
    That's the truth! I've had a couple head gaskets replaced by shops, replaced another myself, have gone through at least two timing belts and tensioners and a list of other things half I noted already. But still after all that it beats a monthly car payment.

  17. #17
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996
    Quote Originally Posted by charger0122 View Post
    idle air control may need reset some vehicles dont have to be reset some do take positive battery cable off for an hour to reset it it clears the computer. clean the mas air flow sensor if it has one.check fuel pressure should be 35-40 lbs.clean air filter or get a new one.if you think it may be a vacuum leak get a can of starting fluid and spray around all rubber vac lines while its running if it idles up check the line for cracks.
    More good suggestions, thanks.

  18. #18
    Guns Network Lifetime Member #2

    Join Date
    Jul 2010
    Location
    Minnesota
    Posts
    4,996
    We can rule out the trans Kadmos, but worth the money to try and maybe worth the $12 or whatever I spent putting it in. It's definitely some sensor/egr. I noticed if I turn the AC or defroster on it bumps the idle speed up enough it won't stall but definitely still uneven stumbling "lean" type symptoms.
    If I'm sitting in a parking lot, put it in drive(without the AC/defrost on) It will idle fine at about 650rpm or so, 15 seconds or so, boom, idle drops suddenly to 500 or less, you can feel it stumbling, sometimes recovers a bit but mostly fighting to idle. I'm leaning toward the the EGR/PCM diagnosis. Will try plugging up the EGR vaccum this weekend.

  19. #19
    Just wondering.Why do you think it is not the transmission?Additives help but dont fix things.

  20. #20
    Senior Member Kadmos's Avatar

    Join Date
    Jul 2010
    Location
    STL
    Posts
    6,871
    Could still be the torque converter, but that alone would normally have the car shuddering as you slow to a stop, not stalling 15 seconds or so after you stop.

    I hate to say but there are so many possibilities that I hesitate to essentially guess.

    I did find what seems like a really good article for you though

    http://www.2carpros.com/articles/engine-stalls

    Best of luck, hope you have a nice cool garage to work in!

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •