runs better when cold

[GTR PrYdE]

maybe this is a dumb question, but ill ask anyways. when the car is cold(93 240), it seems like it gets up to speeds alot easier that when warm. im not talking about racing or even revving that high, but in general, the car gets up to speed faster and feels more torquey. after it warms up it takes more pedal to get it going(not sluggish, i think)... is that normal? thanks guys.

edit: low end feels better when cold than when warm, high end- dunno, try not to rev high when cold.

[Ni2s4s0aSnX]

Well, there probably isn't any sort of problem. It's actually sounds like a good thing. But it's probably just that the air outside is cold and the colder the air, the less condensation and such there is in the intake which boosts performance(the whole idea of a cold air intake) And the reason why it stops after a while is probably because when you first start your car everything inside the engine compartment is cold, so the air that comes it stays cold, but once you drive it for a while, the components of the engine start to heat up, so the engine compartment starts to heat up, which heats the air in the intake.

[DjPantsSpecR]

just wanted to clairify, and to help you feel more at ease.

colder air is more dense, thus there is more of it in a given volume of air. The particles are closer together because they are physically moving slower, less collisons occur and it has more mass per volume

i'm not sure there is less condensation, but who is to say a little water injection never hurt anyone? just kidding

mine does that too, i'm not entirely sure what it is. It will buck because if you touch the throttle at all the torque is outta control and then it causes your foot to buck adn the whole thing jsut happens in a nasty cycle.

i'm gonna dump my pair valve and see if that helps anything at all. Because logic almost points to this as being a possible culprit

[Ni2s4s0aSnX]

Yeah........that too.

[SlowBack]

Mine does the same thing. It makes sense because cooler engines run better (hence the use of oil coolers, big radiators, etc). However, the oil is its thickest when the engine is cold which would cause a bit more friction. My guess is that these cars suffer from the intake pulling air from the same side as the exhaust manifold resides.

Pretty soon, I'm gonna build a heat shield for the intake and I'll let you know if there's a difference.

[DjPantsSpecR]

heat shield on the intake makes an enormous difference. just cut some of the area behind the headlight out, definately worth it

[onosqv]

Depending on exactly what you mean by "runs better", there could be a couple more things.

When your car is "cold", the ecu is dumping more fuel into the system - which makes it seem more powerful.

Also, if the car warms up, and it starts sensing knock, ecu will pull timing, which will make it seem much less powerful.

Have you checked your timing to verify everything is ok, checked codes (even though there may not be a CEL, just in case).

And to help everyone else understand, what is the approx temp outside (noticed you are from TX) when you say "cold" & "warm"

[SOHCSE]

I may be a little off here, but Im a bit confused by the last response.

When your car is "cold", the ecu is dumping more fuel into the system - which makes it seem more powerful.

Doesn't the car gain more power when it has a leaner mixture?

Also, if the car warms up, and it starts sensing knock, ecu will pull timing, which will make it seem much less powerful.

When the timing is pulled, doesn't that enrich the mixture? Contradicting the first quote? If I'm ignorant here, just correct me. Still learning this jazz.

Thanks,Matt

[Reno]

hmmm well about

brokeAs240sx he may be right...

Click here to listen to truth-about-brokeAs240sx

[Reno]

bump for a lil laugh

[DjPantsSpecR]

yes, i did infact enjoy that

and matt, you are correct on both accounts

[onosqv]

Well, can't be right all the time... guess that's what I get for believing what I read on the Internet - or confusing what I read a couple years or so ago when my car felt signif slower when warm than cold and asked on this forum...

So Reno, you believe everything you see on tv? Damn, it's been a year, let this **** die

[Reno]

hey hey im just messin