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850 flashing check engine light, runs really rich 850 1996

posted by  ketchgould on  Sun Oct 10 05:23 CST 2010
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last visit: Tue Jun 11 13:03 CST 2013
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Greetings:

I love my 850, simple problems till now I am guessing.

My car runs very rough at idle, there is a sputtering noise from the muffler and the car shakes and vibrates a lot. The check engine light is on and also flashes for a while. The service light is on for a few minutes after startup. My fuel economy seems (my odometer is broke) to be terrible. Like 12 mpg or so, all of this happened with the shuttering, vibrating car. I replaced plugs, cap and rotor - no change.

Local amatuers say I need my head rebuilt and they will do it for 550-700. They said 2 or 3 of the cylinders have little to no complression. They say my valves need to be replaced. They have done simple work for me in the past (brakes and muffler), not sure if I am ready to have them rebuild the head.

Do my symptoms match their daignosis?

Could it be anything else?

I did leave my gas cap off and fuel door open one night several weeks before the shuttering car and that night it rained. I put isopropyl in tank and also injector cleaner and high octane gas. No change. I have heard I might try a bit of transmission fluid in gas...any thoughts?

Thanks








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    850 flashing check engine light, runs really rich 850 1996

    posted by  tmannian on  Sun Oct 10 07:11 CST 2010
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    last visit: Sat Sep 20 10:31 CST 2014
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    What codes are present when you scan the car? Take it to autozone and read the codes (the port is under your coin tray).

    It sounds like it could be really rich, though it could be many other things... Pull out your dipstick and put a lighter next to it, see if it flames up (meaning gas in the oil).

    --
    If you're not driving it "like its stolen," are you really driving?








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    850 flashing check engine light, runs really rich 850 1996

    posted by  KlausC on  Sun Oct 10 05:56 CST 2010
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    last visit: Fri Oct 24 10:15 CST 2014
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    If the engine is cold when doing a compression check, your readings will be way off, much too low. It sounds like your engine is running much too rich, which also contributes to gasoline washing the cylinder walls/rings and that can also lead to low compression.

    Check all of your vacuum hoses first. Replace any that are split or appear to be cracked. Remove the cover over the throttle body and inspect the hose from the idle air control to the top of the black vacuum tree. Make sure none of the nipples are uncovered, missing.

    Never put ATF in the gas tank! One bottle of dry gas is enough to collect any water and send it to the injectors within the first 5 minutes of running. Remember, the pickup is at the bottom of the tank so that water will be sucked up first.

    Klaus
    --
    Always willing to listen, just not able to take direction.








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      850 flashing check engine light, runs really rich 850 1996

      posted by  ketchgould on  Sun Oct 10 15:26 CST 2010
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      last visit: Tue Jun 11 13:03 CST 2013
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      Klaus:

      Can you explaint the throttle body cleaning process?

      Is there a link?

      Thanks








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        850 flashing check engine light, runs really rich 850 1996

        posted by  KlausC on  Sun Oct 10 16:53 CST 2010
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        last visit: Fri Oct 24 10:15 CST 2014
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        No link, just common sense. That is not your present problem and will not solve your delema. Try to get your codes read, first.

        The throttle body(TB) is under the black cover. There is a thin gasket between it and the manifold, so if you remove the TB, replace the gasket.

        Un hook the cable to the gas pedal, remember which side the cable is on.

        Take off the intake air line, the IAC air line, all of the vacuum hoses, and start unbolting the TB.

        OR -

        If all you want to do is clean the butterfly, just take off the air hose and spray TB cleaner on the butterfly. Use a toothbrush to get rid of stubborn deposits. Wait 10-15 minutes, reattach the air hose and start the car back up.

        If the car was running fine before you left it out in the rain, then just run the engine for 10 minutes. There might be water in the filter.

        Klaus
        --
        Always willing to listen, just not able to take direction.








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    850 flashing check engine light, runs really rich 850 1996

    posted by  someone claiming to be ksg on  Sun Oct 10 05:44 CST 2010 [RELATED]

    If you are sure that the compression is really low then the way to go is to open up the engine to see what is really going on. It's possible a valve job would make things ok. I think their price is low If they are doing the work of taking off and replacing the head. I would want to think about the overall condition of the car before doing this.

    Did you have the trouble codes read, which may be very informative. Ignoring the compression readings, your symptoms are consistent with fuel pressure way too high (bad regulator) which is not a difficult problem. Sounds like you have an internal engine problem but you should eliminate all the simpler possibilities first.

    I would personally not put any kind of substances other than fuel in a fuel system. Even injector cleaners have very strong solvent properties and should be used infrequently if at all.







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