Help With Cold Start

[Vtec6000]

Can someone tell me what afr I should be aiming for when starting engine from cold? Wideband read 10.5 on initial start and rising to 12.1afr. Struggled to stay running on initial start up I imagine its to rich?

[sohcd16y8]

Can someone tell me what afr I should be aiming for when starting engine from cold? Wideband read 10.5 on initial start and rising to 12.1afr. Struggled to stay running on initial start up I imagine its to rich?

I don't ever have a set number for start-up, I usually just go with a car by car basis and roll with whatever runs the best. It usually ends up being a low 13 for a bit then slowly changing to the normal afr as it warms on mostly stock motors. If it is struggling I would imagine it is a bit too rich at first with too low of an IACV duty cycle.

[ckretvix]

I've had trouble with this one since once you start the car when its cold, it doesn't behave the same until its completely cold again. I just aim for best running, which like sohc said is around 13, until it reaches op temp.

[Vtec6000]

Thanks guys. Ill try lower the ECT fuel enrichment. Does the ECT timing correction have much effect on how it runs when it starts up?

[relic1]

Can someone tell me what afr I should be aiming for when starting engine from cold? Wideband read 10.5 on initial start and rising to 12.1afr. Struggled to stay running on initial start up I imagine its to rich?

IMO, too much crank fuel, too much post start. I usually aim for ~12.5 during cranking, then lean it out to around 13-13.5 at ~30*F for post fuel, then leaner till operating temp where I idle around 15.5-16:1 Off idle, 12.7-13.2 at ~30*F, leaning till operating temp at 14.7. but it really depends on what the engine likes, you can tell when it's unhappy, it sounds different.

[Vtec6000]

Can someone tell me what afr I should be aiming for when starting engine from cold? Wideband read 10.5 on initial start and rising to 12.1afr. Struggled to stay running on initial start up I imagine its to rich?

IMO, too much crank fuel, too much post start. I usually aim for ~12.5 during cranking, then lean it out to around 13-13.5 at ~30*F for post fuel, then leaner till operating temp where I idle around 15.5-16:1 Off idle, 12.7-13.2 at ~30*F, leaning till operating temp at 14.7. but it really depends on what the engine likes, you can tell when it's unhappy, it sounds different.

So the crank fuel is causing the really bad running on initial start?

[civic4g]

Shouldn't the default/stock values be \"trouble\" free mainly in a stock engine (like this case)?

[relic1]

So the crank fuel is causing the really bad running on initial start?

crank fuel is causing a slightly sluggish starting and rich initial running condition. post start is causing it to be rich from ~2-15 seconds after startup.

Shouldn't the default/stock values be "trouble" free mainly in a stock engine (like this case)?

default values are designed by honda to be a catch all for all (including worst case) scenerios. They are also set a little rich to help get the cat up to temp faster. Ever since I started reducing the start up values I've had smoother more consistant starts, even in the nice weather we're having lately here in chicago. (-15*F windchill) Plus significantly less fuel out the tailpipe while I'm scraping off the windows. keep in mind these are things that my engines and cars I've tuned seem to like, every engine/setup is different.

[Vtec6000]

So the crank fuel is causing the really bad running on initial start?

crank fuel is causing a slightly sluggish starting and rich initial running condition. post start is causing it to be rich from ~2-15 seconds after startup.

Shouldn't the default/stock values be "trouble" free mainly in a stock engine (like this case)?

default values are designed by honda to be a catch all for all (including worst case) scenerios. They are also set a little rich to help get the cat up to temp faster. Ever since I started reducing the start up values I've had smoother more consistant starts, even in the nice weather we're having lately here in chicago. (-15*F windchill) Plus significantly less fuel out the tailpipe while I'm scraping off the windows. keep in mind these are things that my engines and cars I've tuned seem to like, every engine/setup is different.

Thanks for the help. I'll try chance some values in suggested tables and see how it goes. By the way is there a target idle for cold start?

[jpjackson]

you can set the idle to what ever you want for warm up, go to idle settings and you can change it by ect, look at the srceen shot, it is how mine is set up, higher idle at a lower temp makes it warm up faster.

[Vtec6000]

you can set the idle to what ever you want for warm up, go to idle settings and you can change it by ect, look at the srceen shot, it is how mine is set up, higher idle at a lower temp makes it warm up faster.

thanks once again