Online: Hilly

Surging cold start with tyre shredder kit

  • NickStBob16
    NickStBob16
    6 years ago
    Ive recently had a tyre shredder stage 5 kit installed on my 2016 street bob its excellent and the tune itself is pretty damn spot on ive logged rides and updated my map twice now and its running fair spot on , only issue is the cold start ..... when she is dead cold i fire it up no issues it comes up to a nice 1400 rpm idle and after around 15 seconds it idle hunts up and down from around 1200rpm to 900rpm and eventually sorts itself out after another 20 seconds . I cant for the life of me figure out why ? once its warm it idles perfect it starts perfect and rides great too . If anyone can throw some light on why it does this 15 seconds into the cold start up procedure i would love to hear from ya .
    Its got a 110ci kit , 58mm Tb , hi flow 4.9 gm a sec injectors , 259e cams , se cnc pro heads , hi comp pistons , se billet cam plate , hi flow oil pump and upgraded clutch and currently running the orange super tuner pro box for tuning it .

    Cheers !
  • FONTANA302
    FONTANA302
    6 years ago
    I’d be looking at the Warm-Up Enrichment Table (as the engine starts fine - if it didn't start fine, look at the cranking fuel table)
    This is the electronic choke. It targets actual air fuel ratio points richer on start-up based on engine temperature right after the bike is started.
    When the engine is started, the Warmup Enrichment affect “decays”, or diminishes over a set period of time until it reaches zero, or no effect. The “Decay Time” is time-based, not “table-based”. The enrichment typically lasts about 90 seconds.
    To calibrate the Warm-up Enrichment table, observe how the engine runs on start-up (& cylinder head temperature):
    - If the engine blows black smoke for a few seconds after starting, remove some fuel from the table at the temperatures this occurs at.
    - If engine coughs, or dies, or hesitates, or surges when running in the warm-up mode – increase the Warm-up Enrichment cells to increase the amount of fuel enrichment.
    The table is activated only once per key-on; if the engine stalls and is restarted without cycling the ignition, enrichment continues from its value when the stall occurred.

  • NickStBob16
    NickStBob16
    6 years ago
    Problem solved .... dyno tuned it and found out afr's were in the 16's from idle to 11% throttle we brought them to 13.8 across the board and tweaked some timing cells and she purs like a kitten cold and hot and picked up another 8hp 115.5 hp atw 
  • Daggs
    Daggs
    6 years ago
    Good result. This is why I swear by dynotuning
  • robots
    robots
    6 years ago
    have you compared the 2 maps? must have some significant VE changes bringing it from 16 to 13.8
  • Robbdasnake
    Robbdasnake
    6 years ago

    G`day,
    Just gone this way my self, not together yet, what pipe you running on it there Mate?
    Stay Safe all of yas.
    Snake