I installed a CAI and never looked at the rpms before I did it and with it in it seems to be idling low (a little less than 1000). Also I noticed on the exhaust a black residue. I'm thinking the the engine is not burning the fuel completley so it's leaving the residue and that can't be good for my engine. Any thoughts

 

your car should idle at around 750 rpm.

when does the black residue come out of the exhaust?

if it's at full thorottle, then you're fine. it's just running rich as most cars tend to do.
if it's at idle, then have it checked out... it could be carbon buildup, rich mixture... etc. your check engine light should be on.

 

from what i heard.. to prevent carbon build up.. about once a week.. you're suppose to run your car into high RPMS for a little while-- higher RPMS=higher temperature.. burns away the carbon buildup

 

well the if 750 is the normal rpm cool, but the black residue is actually on the exhaust. This worried me cuz on my dad's car their is no residue.

 

there is always going to be carbon buildup inside of the muffler tip. i wouldnt worry about anyhting.

p.s. i run my car at high rpm everyday

 

cool thanks

 

my car idles at 4-500rpms?? any1 elses? runs fine though

 

how high is high rpm

 

yea mines been actin like that for a few days now .... whats the deal ...

in fact its been idling a little rough .. when i step on the gas and bump up the rpms to around 700 ( where the should be ) it is smooth again anyone ?

MaCe

 

no ever since i bought my car in aug 00 it always idle at bout 500rpm. i have no probs. car runs great though. just thought that was low

 

Did you guys notice that the first mark on the tach is 500? You can't read anything between 0-500, so people assume that an idle of 750 rpm (normal) is 500 since it's halfway between 1000 and the mark between 1000 and 0.

 

well shit i guess i do idle at 750 then

 

i idle at 1500rpm-2000rpm?

 

If you think your idle is to high/low, you can always adjust it.

 

It'll idle high when it's cold, around 1500 or so. Drops to around 800 when it warms up. If it's idling at 1500 when the car is warm, you need to get that adjusted!