car bogs down when started in cold..

[methodchris]

When i start my car when its cold outside/ the engine has completley cooled, it starts up but when it does it bogs down to about 400-500 rpm for a second then goes back up to regular idle. I have brand new Accel 8mm spark plug wires and brand new spark plugs. I have a new cap/rotor coming in tomorrow that I'm going to try but if that doesn't work then what could it be? Slightly clogged injector?

chris

97 240sxhotshot headerweapon-r intake40 series flowmaster / high flow catB&M short shifter17"ADR skye-7'slimo tint!

[Jonny 290]

happens to me too, i'm not too sure if it's a serious problem.

my car runs pretty snappy, but it's a beast to start in the cold. it'll chug at 200, trying to start, then will rev to 1200, then will die back down to 600, then will stabilize at 850 with fans off.

[916drifter]

Same thing happenes to me but when it goes down to 500rpms, my car starts to shake a lot. but my neighbor told me i should try fuel injector cleaner and says its my fuel injectores..i dunNo if that ill work but o well

[NISTECH]

Your cars are choking on fuel. You dont have enough oxygen going in to help the fuel burn. You guys need to start with a good decarb on your intake systems. Cleans all the carbon off the throttle body and through out the air intake system from the throttle body back. AFTER you do the decarb reset or check your base idle setting. The reason the idle bounces all over the place is the IAC valve is hunting for the best idle air mixture.Carbon build up and inproper base idle settings are the #1 cause of hard cold starts.

Cold air is more dense the warm air so your oxygen content is lower.

[methodchris]

RPMS arent jumping on mine tho. throttle body was just cleaned a few weeks ago. Its missing so its gotta be a slightly clogged injector ?

[NISTECH]

maybe not maybe your spark plugs are not hot enough..are you using NGK's?

[Nismo_Freak]

Cold air is more dense the warm air so your oxygen content is lower.

Cold air contains more oxygen molecules per volume because it is denser

Density = Mass / Volume

[methodchris]

yep, ngk platinums

[NISTECH]

Cold air contains more oxygen molecules per volume because it is denser

Density = Mass / Volume

I am glad someone here is up on their rocket science. :pface

there is not enough air getting into the cyl. thats why the fuel is not burning and it is flooding out.

[Nismo_Freak]

That or there is excessive line pressure due to a faulty fuel pressure regulator causing excessive fuel to be dumped in.