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Strange idle issue.

Discussion in '200, Avenger/Sebring, Cirrus/Stratus/Breeze' started by ironman187, Jul 30, 2017.

  1. ironman187

    ironman187 Active Member

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    Hey all,
    I finally finished putting a 2.7 engine from a 2001 Sebring into a 2006 sebring. I put a new water pump, timing chain, and timing tone ring sprocket (for a 2006) into the 2001 engine, swapped out all the sensors on the block except the oil sending unit, and used the 2006 fuel rail, injectors, valve covers, ignition coils, knock sensor (using a custom made adapter stud), flex plate, and intake. I started it up tonight for the first time and it jumps right to the rev limiter for a second, then drops down to almost nothing and surges to 1200, is does this for a few revs, then starts misfiring while surging. I'm not getting a code for the misfires oddly enough. I am getting a p2074, p0038, and p0068. I'm completely, lost, what am I missing?
     
  2. Gerry G

    Gerry G Well-Known Member

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    The are two things that come to mind, one is the TPS is bad or not plugged in. The other is a major vacuum leak like an intake manifold gasket slipped out of place. Both these are called out in 2 of the codes you posted (the map sensor affected by the vacuum leak). It may also be the map sensor is bad or not plugged in but I have not seen a motor act this way with the map sensor.
     
    #2 Gerry G, Jul 31, 2017
    Last edited: Jul 31, 2017
    ironman187 likes this.
  3. ironman187

    ironman187 Active Member

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    Ok, so the issue seemed to be a major vacuum leak. I accidentally used the wrong bolts, so the intake manifold wasn't being held down completely. However, now I have a high idle at around 2300rpm, the only code that is being thrown is the p0038, which I can't imagine would cause such an issue.
     
  4. ImperialCrown

    Level III Supporter

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    Have you reset the adaptives with a battery disconnect/reconnect? A fast idle is still a symptom of a possible vacuum/EGR leak. Is the throttle valve closing completely?
    If you hear a loud hiss, try to locate it.
     
  5. ironman187

    ironman187 Active Member

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    I disconnected the battery, the throttle is closed, I cannot hear a hiss anywhere, and there is no EGR valve on this car that I can find. I have it up on jack stands, so I put it in gear, and the RPMS drop to about 1000, but it jumps up around 2k in neutral and park. The CEL started flashing, but once again, the only code stored is the P0038.
     
  6. ironman187

    ironman187 Active Member

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    New symptom! I'm now getting a p0300, also a lot of smoke from the exhaust system. I wrapped the pipe that runs next to the oil pan in a heat wrap, so I thought it was just burning off manufacturing oils, but now I suspect something more sinister, it smells like burning motor oil and something else which I can't pin down. In looking under the car, the smoke seems to mostly be coming from under the wrap oddly enough. The burning oil smell is likely from a valve cover gasket not seating properly. The valve cover gaskets are brand new, but the front and rear catalytic converter to exhaust manifold are not. I was planning on replacing those once the car was up and running (I'm on a time crunch to get it drive-able. At any rate, could a leaky valve cover gasket be a vacuum leak? Or possibly a leaky manifold to converter union?
     
  7. ImperialCrown

    Level III Supporter

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    I was going to say, a flashing 'ck eng' light can mean something that could potentially damage the catalytic converter (i.e. - misfire). A leaky valve cover would not be a vacuum leak, but if the PCV is running with poor vacuum, it can push oil out of the engine.
    Exhaust manifold would also not cause a vacuum leak.
    Double-check your reassembly, something isn't right. Spark plug tips may show carbon fouling? This can cause misfire and may be a symptom of an over-rich mixture condition?
     
    ironman187 likes this.
  8. ironman187

    ironman187 Active Member

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    Haha, oh gosh. Remember when I said I used the wrong bolts for the intake manifold? Turns out that because they were too long, I damaged the aluminum intake surface on the block. I found out because I made a DIY smoke generator so I could find vacuum leaks. I saw smoke whisping up from under the intake manifold, it was hard to pinpoint, but looked like it was coming out from under the plastic adapter plate. Since I had to swap fuel injectors, I figured the plate moved. I removed it and saw the dents in the aluminum. Stoned them out, cleaned everything off, and replaced the gaskets. It runs and drives just fine now. All I have left to do is find the oil leak. Thanks for all the advice!
     
    ImperialCrown likes this.

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