My bumper is turning black lately, which from what I've read means that I'm running rich. It wasn't doing this before, but it could be because I've been hitting vtec alot more often lately. Is it normal to run rich when hitting vtec alot? If not, is there anything I can do? This car is stock btw.

Also, a side question (or possibly something related)... I'm overdue for my 90k maintenance and was just wondering if some of that is something that I can easily do, perhaps for less money than paying someone to do it for me. Also, do I need a new timing belt at 90k or is it at 120k that I need it? I've had mixed advice. What kinds of things need to be replaced/checked at 90k? I've been having some rough idling as well, and was thinking that the 90k maintenance would fix that. Also was suspecting either the battery or alternator, since when I roll my windows up and down my idle drops o_o

Any advice would be

 

In terms of running rich, my stock 00 GSR does as well. Rich is safer than lean in terms of avoiding detonation, and I'm betting all stock tunes are a bit on the rich side. It is normal to puff a little black smoke during the transition into vtec as well, which could also be marking the bumper.

 

Yea if you do run your high lobes then you are going to run richer and you are going to get that bumper a little more black. as for the rough idle, how are your driving habits, do you redline your motor? if so, you might have to change your head gasket, the rought idle might do it part with your battery/alternator. You can check your alternator but using a volt meter and seeing if it is cranking out 13.5~14 volts. If you cant get your hands on one, turn on the car and disconnect the potive terminal on your battery and see if it still runs fine. If it starts droping, your alternator is bad.

 

hmm, i'm starting to think it's mainly my alt/battery... yesterday, my idle was really low, but when I turned off my headlights it went up and when I turned off my radio too it was up to the normal 800. turned em both back on and my idle went down to like 500 at a stop. At a coast in neutral, idle seemed fine, but once I got to a complete stop it would dip back down again. If I turned up my speakers a bit, the lights on the HU would start dimming. If I turned em up a bit more the headlights would dim with the beat.. which is actually kinda cool but.. not good.

 

If your car didn't leave a deposit on the rear bumper before, it's probably not running rich. The factory tune cannot change just like that.

It might be burning oil. Considering you mentioned you hit vtec more often, that's probably what it is. Oil will leave grime on your bumper as well.

VTEC = oil burn.

 

check ur o2 snesor??

 

Getting back to your 90k maintenance question according to the manual you check your timing belt and replace if needed which to me means replace it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by enil01 &raquo;</TD></TR><TR><TD CLASS="quote">Getting back to your 90k maintenance question according to the manual you check your timing belt and replace if needed which to me means replace it. </TD></TR></TABLE>I agree; as long as you can afford it, change the timing belt. You shouldn't have to worry about it ever again as long as it's put on right.