93 Civic
b16a2 (bolt ons, CTR cams, Mugen ECU)

When cold, my car sounds like a V8 with a wicked cam. Sounds nice, but I don't think it's supposed to be this way. I do have CTR cams, but I know these aren't that wild.

Also, when cold, if I don't give it gas it will kill itself. I think this is because it runs too rich. All fuel systems are stock. Anyone have any ideas?

 

most likely its running rich cause when the coolant sensor tells the ecu that the engine is cold the ecu send out a richer mix to warm the engine faster, only problem is that if you already are running rich on the bottom end its gonna be exactly like what you said. my car has the same problem but only does this in the winter time also. then when the car is warmed up it runs fine. go figure.

 

also from what another person told me is that it could be my iac

 

if your running rich try to replace your O2 Senor, just don't go to a mechanic to do that, buy it yourself online somewhere so its a hell of a lot cheaper.

 

i agree

 

just a tip guys, O2 sensors never die, they get murdered. O2 sensor only got bad if there is a short in it. other than that all you have to do is put the O2 sensor under a torch(blue flame) and heat it till its cherry red, make sur you hold it with a visegrip or something of the like this process burns off all the carbon clutter on the O2 sensor that was causing it to send out signals that it was rich cause it cant read the pressure properly. but if its a short in the sensor, replace it of course.

 

Your computer doesn't look at your o2 sesnor for input on a cold start. It won't start looking at the o2 sensor until the car has warmed up. Could you possible be hearing an exhaust leak? Is it like a ticking poping noise, like a lawn mower? I've seen cracked exhaust manifolds before and sometimes aftermarket headers give you really thin mounting flanges and they tend to warp creating an exhaust leak.

 

Exhaust is fine, from the header back. If you've ever heard an old muscle car with a wicked cam, that's EXACTLY what my car sounds like when cold. (that lumpy idle sound) I plan on checking the cams, adj. cam gears, and timing to make sure everthing is kosher.

It idles better once it warms up, but it still runs pretty rich. It stinks it up pretty good. :dunno: I'll poke around and let you guys know if I find anything.

 

vermsta is right, most of the emission system only takes effect when the car is fully warm, thats why they warm it up well when you smog it. here is a suggestion, I may be wrong but it is just something to think about, people on the S2K forums I think its S2K.com or something, were saying that a lumpy idle and the car dying etc when it is cold could mean that the valves need to be adjusted. They also said it has the lumpy idle or dies when the valves are too tight and if they are too loose they will "valve tap" It could have nothing to do with your car but it is just something to consider....... did you check out your IACV abd fast idle thermo valve? thing is, when those get dirty they tend to stay open and keep the idle too high instead of too low, does your car run OK when it is warmed up?

 

thats why he's wrong, tell me this then, i had a bad o2 sensor when i drove for about 2 mins my check light would come on, Heat guage still below cold, i could drive 12 hours in 20 degree below weather and my heat guage would still be below cold, and when i pop the hood my engine is just a little bit warm, my radiator is taking in too much cold air, so tell me what one... i already replaced it and it was the o2 sensor but why was it working when my engine wasn't even warm???