I bought a 2000 z28 recently with 80,000 miles on it and a few mods done to it. I like the car so far but it doens't seem to run exactly right. It idles at 500 rpm when it's in gear which to my understanding is kinda low. It only idles at 600 in park. When i first start it smokes just a little bit and the exhaust tips appear to indicate it's runing rich. I'm guessing thats the case due to the built up carbon on them. When i stop at a light the car stays running just fine but as i come to a complete stop the computer kicks the idle back up on the engine to about 800 or so then lets it go back to idle. Is this normal? I'm kinda curious if the car maybe has a cam in it or has been tuned useing a handheld. It does have a few other mods on it so i know the guy wasn't scared to change stuff. Oh yeah and the service engine soon light is on.

PS i'm pretty sure he said he was a member on this board.

 

thats about right for an auto rpm wise. the smoke on start up could be a lot of things. what color is it? could be fuel, prob not though. prob a combo of valve guide seals, rings, and pcv and it lettng oil in the intake.

 

It smokes like it's a real cold morning even when i start it on a warm morning. Thats the best way i can describe it. It's kinda white. It doesn't seem to be burning oil at all. Is it normal for an ls-1 to run kinda rough? When it idles and your in the car it has a slight jerk to it like it's missing but it has new plugs and wires on it. I know the engine has been apart before because it is missing the bolts that hold down part of the air intake and the MAF wasn't installed properly on it either. I'm kinda worried that i bought someone elses problem. But the car hasn't let me down at all and i've been driveing it 20 miles each way to work. Maybe i'm just being paranoid.

 

500-600 rpm's is normal for an automatic at idle.

If it doesn't have cats, some white smoke on first start-up is normal. I know mine does it.

 

the running rough might worry me, and less it does have a mild cam in it. My automatic idles low, about 500rpm in gear, say 650 at idle. Runs smooth as silk though, put a dime on the intake manifold and it wont fall off.

 

Might have a small vacuum leak. That'd cause it to run rough.

 

Not usre if you were being literal about hte dime thing but the engine is running smooth enough that a dime doesn't fall off. I think i'm just being paranoid but the SES light is on for some reason. Then again my moms 97 blazers light has been on for 40,000 miles for no real reason.....

 

i was actually being serious about the dime thing Just tried it out one day... In regaurds to the SES light, i'd get it checked out. It could be something stupid...but good to know what it is, its on for a reason.

 

Well i took the air box cover off to look at the filter one day and noticed that the MAF screen was clogged with plastic so i took it apart to clean it and noticed it wasn't installed right on the lid. It was loose and letting in air. I wonder if that was the issue? I also decided that since the free ram air mod was done to the car that i should check to see if the EGR tube had been cut also and it has been. I read online that if you don't do it right it will cause a vacum leak. I think that is what is makeing it run rough. I'm gonna buy a new one and a new o ring and see if that fixes it. Now that i think of it my moms blazer did need a new oxygen sensor when it was on.

 

you can go to advanced auto and they will check and see what code(s) your car may be running and check it out on the computer to see what the problem is .

 

all those things are good ideas...clean up the maf screen, install the maf properly. Put the new o-ring on the egr tube..make sure it isnt crushed or anything.. I'd still check the codes...and go from there

 

The light went off today...... i removed the egr tube the previous day and reinstalled the o-ring. I wonder if thats what made it go off. I correctly installed the MAF as soon as i realized it was messed up and cleaned it out good.