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Running rich, FML

Discussion in 'HYBRID -> EG-EK / DC' started by doEKi, Jan 21, 2013.

  1. doEKi

    doEKi New Member

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    Yet again my b18c swap has run into trouble. (b18c block, p72 head, oem type r style TB/MI, AEM CAI, oem exhaust manifold, P73 ECU)

    Last time it was leaning out horribly STFT (maxing out at +45.9%. Now at idle the STFT will range between -16% to -24%.

    Now the ECU is having to remove fuel.


    I managed to get the car to pass smog (CA). Yet on the HC's I barely passed by reaching the maximum allowed 60ppm during the 15mph portion of the test.



    Things that I have checked;

    -TPS: about 9.8% w/engien off
    -Ignition timing: 16BTDC
    -MAP: at idle less than 10.5 Hg" (2.9V)
    -Valve timing: IN 0.007 & EX 0.008
    -Spark plugs just replaced (NGK iridium)
    -Cap & Rotor replaced
    -Both oxygen sensors have been replaced
    -Removed catalytic converter: no signs of contamination or damage
    -IAT: same as ECT in the morning (~48 degrees) 2.6V
    -ECT: same as IAT in the morning (~48 degrees) 2.6V
    -Last engine compression: about ~230psi results in all 4 cylinders
    -Removed fuel rail (engine off key on) no injectors leaked
    -Spark plug wires are MSD super conductors about 6yrs old
    -Fresh fuel
    -PVC valve; shake, can hear clicking


    The only thing I have began noticing on the dash is that the coolant temperature tends to stay below "normal" or the middle level. It used to stay right in the middle an now it sits a little lower.

    Yet I also upgraded the cooling system (racing rad+fan+thermostat+fan switch+rad cap) with mishimoto/mugen parts

    But even thought I did modify the cooling system maybe the temperature sending unit or the ECT is going bad??? thus the rich condition?? idk
    Iv'e wondered if it might be a vacuum leak causing this problem; excess air=more fuel, but have been able to find nothing




    Sorry about the long story but I think it is relevant information to the problem and a possible solution.

    Please advise & Thank you
     
  2. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    Bad ECU?
     
  3. |Chaz|

    |Chaz| Well-Known Member VIP

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    I actually recently had my ecu go bad. It was literally the last thing I tried replacing because I had just "replaced" it a year or two ago. Fixed all my problems other than needing to go from a one wire O2 sensor to the standard 4 wire.
     
  4. Fernpatch

    Fernpatch Member

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    The TPS seems a little high to me. Also what does the MAP read key on engine off? What does the ECT read when the engine is running at normall operating temp?
     
  5. doEKi

    doEKi New Member

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    Hey guys thanks for the replies.

    As for the ecu I dont think its bad because when it used to be going lean it was due to the injectors being from the wrong engine (from a 96 civic sohc I believe). I ordered injectors from a 98 dohc gsr and that fixed the "leaning" problem.

    The thing is that when cold the fuel trims stay relatively close to 0% as it should be. As the engine warms it tends to go rich, fuel trims begin to steadily climb -3%.....-8%.....and so on to about -24% now.



    As far as the TPS is concerned I looked it up in the manual and it states that with the engine off it should be approximately 10%, so I guess that's ok.

    MAP last I checked with the engine off key on; 2.9V

    As far as the ECT voltage I have never checked it once it is at normal operating temperature, rather with the scanner I can see that the temperature goes up to about 208F and the cooling fan will kick on around that range.
     
  6. doEKi

    doEKi New Member

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    Out of curiosity thought did your CEL come on?

    Or did you just find out your ECU was bad because the problem was solved once you changed it?




    I had my friend drive behind me. Under normal acceleration he told me that there was no distinctive or unusual smoke from the tail pipe but when I would accelerate rapidly he would see dark black smoke coming out of the exhaust; the excess fuel.

    As far as the manual is concerned a rich fuel condition can be caused by:

    -Bad FPR
    -Fuel return pipe clogged
    -Fuel injector leaking
    -Gasoline not at manual spec
    -Primary H02S deteriorated
    -Valve Clearance
     
    Last edited: Jan 28, 2013
  7. Fernpatch

    Fernpatch Member

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    Are your new fuel injectors oem?

    I would like to know how hard in the throttle you were when your friend saw black smoke coming from your tail pipe. most if not all ecu's are programmed to go back to open loop fuel control when you reach a "full throttle" condition.
     
  8. |Chaz|

    |Chaz| Well-Known Member VIP

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    My ECU didn't throw any codes until it was literally on its last legs. Had a bunch of odd symptoms prior to that. Hesitating on the freeway, sometimes it wouldn't run right if it was hot. Finally it threw I think it was a MAP sensor code. Followed the manual's diagnosing tree and discovered it was a bad ECU. Replaced the ECU and now no issues.
     
  9. doEKi

    doEKi New Member

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    I was driving at WOT on 1st then 2nd probably 50-80%. These are estimates though I am going to drive again today and record the live data while driving.

    Injectors are oem from a gsr.

    I'm going to look up a diagnostic for the ecu I really don't want to replace this one again. It used to have a jdm p73 but since you cannot do obd diagnostics I god the usdm p73


    I've been thinking about getting a adjustable FPR but I don't want to mask the problem.
     
  10. doEKi

    doEKi New Member

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    What about ignition coil ima look into that tonight.
     
  11. doEKi

    doEKi New Member

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    Was driving home. CEL got set while driving on freeway code p1457. Maybe this will solve my problem looks like its a evap leak fault code
     
  12. dc4dude

    dc4dude Member

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    The last time i had that kind of an issue (chevy cavalier) black smoke, running super rich... It was the up stream oxygen sensor... Throwing everything off... At start up, it would run fine, fuel trims were where they were supposed to be, but as soon as it would warm up, SUPER RICH... Good luck dude.
     
  13. doEKi

    doEKi New Member

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    I wish it was the oxygen sensor I have a spare in my garage. I found diagnostic steps for the EVAP leak i'm going to get a vacuum/pump tomorrow to help find the leak
     
  14. Fernpatch

    Fernpatch Member

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    Good luck with the evap code. let me know when you are able to confirm the scan data on the highway.
     
  15. doEKi

    doEKi New Member

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    Well I got as far as I could today trying to diagnose the EVAP system leak.

    The vent shut valve and EVAP solenoid held vacuum and tested ok. Whats left to check this weekend is the EVAP two way valve.

    As far as the fuel trims, during freeway driving stays closer to 0% and -2.3%. The problem is when I get to a stop light it starts going steep rich again. Also under heavy acceleration the short term fuel trim initially goes + and then it would go to 0%. Under normal acceleration the fuel trim fluctuates between rich and lean but tends to stay on the rich side.



    My hydraulic car jack doesnt hold pressure so I cant even jack up the car to check the EVAP two way valve, but if its the EVAP system i hope it solves the running rich.
     
    Last edited: Jan 30, 2013
  16. dc4dude

    dc4dude Member

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    I wrote this on another running rich thread.... Bad fuel pressure regulator? What kind of fuel pressure you have? What about an injector that is sticking open? Or not closing all the way.
     
  17. m90polk

    m90polk Member

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    Not to bring this back from the dead a month later but just windering if the op solved the problem??
     
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