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Thread: E38 idles and runs great... hard start though??

  1. #1

    E38 idles and runs great... hard start though??

    Thanks for reading! I finally got this thing idling nice, and returning to idle properly with BigMike42's idle post for gen 4. Now, it has a hard start issue when warmed up. Please tell me, what perameter I'm missing that can fix this? Thank you so much and look forward to a response!

    BTW, its an 09 G8 with cold air, long tubes, no cats, solo straight pipe, and 232/234@ .050 112LSA cam

    Guidos Pontiac idle tuning2.hptGuido Pontiac idle log.hplidle layout.Layout.xml

  2. #2
    Is it rich right after startup, might be cranking fuel, if it's lean could be warmup tables and/or injector temp

  3. #3
    Quote Originally Posted by geneass View Post
    Is it rich right after startup, might be cranking fuel, if it's lean could be warmup tables and/or injector temp
    Thanks for the response! I am not really sure if its going rich or lean, this is my first time attempting a tune without a wideband. Which warm up tables are you talking about? Oh, by the way, the hard start is only while its warm, starts fine when cold. just figured that out

  4. #4
    I like to use a wideband but you may be able to use your STFTs. During cranking the ECU uses the cranking fuel imagine that ha then it uses the warmup table til it gets to oper temp. If it were me I'd use stft and watch right after crank see how rich or lean you are and adjust crank fuel then when that's good cold crank and log all the way to operating temp 190ish. Go back and see how far stft are off and apply to warmup table. May take a couple cold cranks

  5. #5
    Senior Tuner
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    if u cant see whats going on with a wideband u can during hot cranking just hold ur foot on the throttle a little bit and if it starts up good just add a little more startup airflow, if it still dosnt start then add some fuel (make sure u adjust the right cells based on your engine off time in that table) and then try again without the throttle help, i think ur airflow is ok as it jumps up in rpm when it does fire so it prob more a fuel or spark thing, also the -10 in the crank spark make that whole first half row 5 and second half 10 see if it helps