is the ignition timing more advanced during cold start compared when it's fully warmed up?

another question is, why is it that the car pulls stronger when the engine is "just started" or cold? the difference is very noticeable between "cold" and "fully warmed up".

cold engine stronger pull?

EDIT:

here's a more detailed version

my observation is:

a car just started and brought up to operating temp PULLS STRONGER

VS

a car ran for like 50kms

 

Couldn't answer you're first question but to give you a slight answer to the other one.

1. Car is in open loop when cold
2. Meaning it runs on pre-set ecu values for timing and fuel and ignores certain sensor signals.
3. This tells YOU that you have some sensors that might need replacing that are getting old and slow or need calibrated.
4. Probably shouldnt be doing "cold pulls" in your car. Let that **** get to operating temp before you smash on it if you aren't.

 

very informative.

but vtec wont activate if its not within normal operating temp right? plus my temp gauge is at halfway when i try it.

my observation is:

a car just started and brought up to operating temp is STRONGER
VS
a car ran for like 50kms

lemme edit my post above.

 

Absolutely right about vtec. I'm not sure about a car just reaching operating temp compared to one that has been ran for a decent distance. Is it very noticeable? Any CEL?

 

No CEL so far. So this isnt normal at all?

 

Well I wouldn't say it's normal but its not crazy or exactly a bad thing. If no Cel than all should be good. You probably do have some sensors that need replacing / a tune up. Don't know the history of your car, just suggesting.

 

I was thinking it may be psychological. Lol.

 

Haha, that could be it as well. If you've never replaced your O2 it might be getting slow at reporting values back to the ecu. And if not mistaken most Hondas ignore the O2 until fully warm.

Some of it might be in you're head, some might not. If you have a buddy to help you and you're curious about the condition of the O2 sensor, use a multimeter and see how fast it can change voltage when throttle is applied. Analog meters work best for this but a good digital one would work fine as well. You simply determine which 2 wires (if 4 wire o2) are for signal, hook leads to them. If one wire o2, positive lead to o2 wire and ground to a good ground.

 

The longer it runs, the more heat soaked the intake manifold gets (not the filter on a stick - the actual cast aluminum manifold that bolts to the head). As the intake gets hotter, the air that reaches the combustion chamber loses density. Less density = less oxygen = less fuel = less power.

Crank ignition timing; yes, colder temps require more advance because the fuel isn't vaporizing in a cold engine. But if your management system doesn't have a temp. based table for crank timing (like AEM), you have to find the best compromise between starting quick when it's cold and bucking when it's hot. In most cases, your idle timing should be pretty close to your optimum crank timing. It's a good starting point anyway.

 

Pull the plugs and see if your running rich once warmed up, if so check the ECT sensor. 94