Cannondaleriders

Went to the dyno with my open air ported 450 2.2 stroker and dialed in a nearly perfect afr with the trinium map by dialing in a 1925 flow rate.
So the problem is that it starts horrible, poping out the intake, erratic idle and stalling. You have to give it a little throttle to keep it running after it hits and it does not seem to like to idle below 2400.
It seemed to help some with the erratic idle when I took the offset from .88 to 1.05 and the leak from .5 to .3 but I have not tried to start it cold yet.
Dyno operator said that it was idling lean and if I could fatten it up down low it would start a lot easier and idle better.
Can I do this with offset and leak or do I need to change the cold start fuel or the fuel settings in the bottom of the map?
If I mess with the offset and flow is it going to effect that good afr?
What do I need to adjust on at this point? Do ported motors need to idle higher?
Seems to be well known that ported motors like less fuel down low but this one seems to be the exception!
Ray

Don't let the offset and flowrate numbers fool you, they are very specific to the injectors. As for what to do, well...you should have done that on the dyno. Changing the offset will affect the flowrate some. Just raise it up some and see how it affects it.

Yes any adjustment to flow or offset now is going to make your dyno session null and void.However all you need to do is adjust it in the map.Before doing that make sure your IACV is working properly.If its not that will cause a lean condition.Once the quad is warm coldstart fuelmass isnt doing anything.

I suspect the ISCV is sticking on the motor I just put in the Speed but I got it to behave at idle by putting a big leakage number in, 5.0 I think it ended up with. It was just a quick-fix to get some running-in hours on it. Leakage setting should hardly affect the AFR at larger throttle openings at all so I would be tempted to try that first. If it ends up idling too fast with the leakage up then the ISCV is probably sticking like mine - so fix the ISCV first.

Injector offset refers to the difference in opening versus closing times (or ramps) of the injectors, sometimes it is called 'injector dead time', and adjusting the offset will affect the full-load AFR, more at lower rpms and throttle openings than at full throttle and high rpm's. This is because the injector dead-time is very small in comparison to the actual duty cycle when demand is high.

Hi,

What and where is the ISCV? what can be done to fix/unstick it?

Thanks

God bless...

Mark

Idle Air Control Valve.Its the 1x2in black square on your throttlebody.Its a plunger that allows air to bypass the throttleplate its controlled by ecu and is always working even when warm.What it does is leans out mixture to maintain your idle.They get dirty or often just fail.Do a few searches on this.