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Thread: Misfires when cold only?

  1. #21
    NostraJackAss Jack@European_Parts's Avatar
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    Look up the heat range of what you are using and then cross over and select the next heat range up and experiment looking for the CF and how it runs.

    It would be best to verify if this is a ground/supply voltage or pulse issue and or intake leak before playing with the heat ranges/fuel injector move swap!.....?

    Is the compression in this cylinder comparable to others? Do a leak down cold to make sure and a swab ( long flexible Q tips )of cylinder for traces of coolant to see if any type of small leak exists cold and goes away during heat transition.

    I like back to basics......

  2. #22
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    Jack,
    Just a thought to myself when the car was cold I unplugged the camshaft control valves and started the car and the misfire situation was reduced my 75% lots better but not perfect. I did an output test on the control valves and I don't get any kind of a result out of the test, what am I looking for ? Also in Adv measuring blocks I have Duty cycle ,requested,and actual. What am I looking for as far as Normal warm up cycle and warm conditions? I would like to carry out any test on the circuit first before I dive into the cam dept looking for a broken control ring or foreign matter from the cam to the VVT sprockets. From what I understand the intake cam sprocket retards timing on start up for emissions maybe it is stuck , I have seen may videos and posts regarding the control solenoids getting stuck on the W8's and people zapping them with voltage to put them back on line maybe this is the same??

  3. #23
    FoRT jyoung8607's Avatar
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    Quote Originally Posted by R32topher View Post
    I am currently running E85 fuel should I fill up w 93 to do the logs?
    Dump the E85. Your car is not designed for it, and it may be your problem. Even if it's not the problem, it's interfering with finding your problem. Even if the car ran "fine" on E85 before, your altered cams and tune may not tolerate it as well. Google search "trouble starting cold on E85".

    Jason

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  5. #24
    Benevolent Dictator Uwe's Avatar
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    E85? How did I miss that. I'm surprised it runs at all. E85 is 85% ethanol and should NEVER be used in any car that isn't EXPLICITLY designed to run on that.

    -Uwe-

  6. #25
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    The car has a Flex Fuel tune in it and I am not the only one running this tune with cams either. Like I said it seems to be in the timing circuit for cold ENGINE temps on the warm up cycle because the car runs great once it is up to temp. The Google search referred to is regarding parts of the country that have cold ambient winter temps as the Alcohol based fuel hates cold outside temps. The car is filled up with 93 pump gas now and still misfires when the Motor is on the warm up cycle.

    High ethanol blends present a problem to achieve enough vapor pressure for the fuel to evaporate and spark the ignition during cold weather (since ethanol tends to increase fuel enthalpy of vaporization[40]). When vapor pressure is below 45 kPa starting a cold engine becomes difficul

  7. #26
    Benevolent Dictator Uwe's Avatar
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    Quote Originally Posted by R32topher View Post
    The car has a Flex Fuel tune in it
    Pardon my skepticism that it's possible do "Flex Fuel" correctly with an engine management system that wasn't designed for it to begin with. Does this "tune" include a sensor that tells the ECU what percentage ethanol is currently in the fuel? Or does it simply remove the range checks for fuel trims? I can see 3+% difference in fuel trims between real gasoline and the E10 swill that passes for gasoline in most places these days. That makes me wonder how much the fuel trims change going from real gasoline to E85.

    Oh, and pardon my skepticism that it makes any sense at all to turn a food crop (corn) into fuel, especially when the total energy put into making that ethanol is roughly the same as what you get out of it again when you burn it. If you count all of it -- from the natgas that was used as a base for the nitrogen fertilizer, to the diesel that was burned planting, tilling, and harvesting the corn, all the way through to whatever energy source that was use to distill the ethanol -- you find that using ethanol for fuel in a temperate climate like ours is nothing but a welfare program for corn farmers and ethanol producers. This in turn increases all of our food costs due to a completely distorted market for corn.

    [/rant]

    -Uwe-

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  9. #27
    NostraJackAss Jack@European_Parts's Avatar
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    Oh Face Palm..............

    I think that a retrace of steps is needed because of the variable of hardware/tuning...........

    I would put back to stock with a stock ecu and cams.......verify everything is correct and then start over.

    It may sound dumb to some people......however, hey that's how I fix 99% of things that have things deleted in tables........ which aren't being reported to me in the diagnostic stack...............because it was basically NOP'd with 90's as a figure of speech.

    Even an attempt with a stock ecu and gas as fuel is advised............. then going cams/tree adjuster............if you must.

    I have a good tree adjuster I verified before removal during a similar situation if you need one............

    One quick question?????
    Do you have a picture of the tree adjuster with the noids installed I can see or post?
    You know the back part where they look like torx heads inside the noid.......

    Please advise..........

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