baddogz28

iTrader: (6)

My car has been acting up lately... At a stop, the idle is fine, 700-800 rpm. Once I start moving, when I am shifting between gears the revs surge to 1800-2000 rpm, and I can't figure out for the life of me what the problem is. On the highway today, the car was slowly accelerating on its own when I put it in 4th around 1200 rpm, and I'm starting to get a little annoyed with this ****. As I slow down to a stop, the revs drop from 1800 or so down until I am stopped and it is again less than 1000. Any ideas what the problem may be, fellas?

Keenov

iTrader: (5)

Have you checked the throttle body to see if it was sticking?

I didn't understand the last sentence that well

baddogz28

iTrader: (6)

Yeah, I did and it doesn't seem to be... As for that last sentance:

Say I'm going 20 and I put it in neutral and start slowing down. The revs drop progressively from 2000 rpm as the speed drops until I am stopped and it's back to normal again. I guess it's tough to describe.

bad2000ss

iTrader: (6)

If i have the car in neutral coasting at 15-20mph the rpm is about 1100-1200. When I come to a stop the rpm will drop down to normal. 2000rpm seems high, put it is perfectly normal for an fbody to "keep the rpm up" coasting in neutral untill you come to a complete stop. I've seen the rpm up to 1500 or so coasting at higher speeds.

I honestly don't know why the car does this or what causes it to do it, but i've never ridden in a manual LS1 fbody that didn't do it.

baddogz28

iTrader: (6)

Yeah, but the car accelerates on it's own up to 2000 rpm in 1st-4th. That **** ain't right.

Schon

sounds like your clutch is not fully disengaging. you get any work done on it recently, or burn it badly?

baddogz28

iTrader: (6)

Well, had a new slave installed in June, other than that I smoked it a little bit july 4th doing a brake torque.

Schon

in your first post you said that your idle is fine at a stop. Are you putting it in neutral at that time? does your car move when you idle in 1st with the clutch in?

baddogz28

iTrader: (6)

Nope, but I was in the store parking lot today and the car wanted to accelerate when it should have been at an idle. Not acclerating hard, but it wanted to rev to 1900, in gear or out of gear.

z28nbr1fan

Try resetting the PCM (computer). It can't hurt to try it. Turn the key a quarter turn forward to put the accessories on. Pull the PCM battery and PCM accessory fuses. Leave them out for about 5 to 10 minutes. Put the fuses back and then restart the car. The computer will begin to set the idle and reconfigure the timing. Hope this helps.

glennhl

I had the same problems a little over a week ago. I pulled out the IAC Motor/Valve and cleaned it really good including cleaning the seat in the throttle body. That fixed it!

killer01ws6

I think it is in your IAC also.

baddogz28

iTrader: (6)

Thanks guys for all of the great ideas! I'm going to try to reset the PCM first.

What is the IAC? I have never heard of that part...

glennhl

The IAC is on the driver's side of the throttle body. There are two electrical devices on the side of the throttle body. The one in the middle is your TPS and the one on top is the IAC. Unplug the connector to the IAC and take it out by removing the two torx screws. Don't lose the O-ring. I used WD40 to clean up the IAC and then used WD40 to clean the inside of the throttle body where the IAC valve was.

The IAC is a stepper motor valve that allows some air to bypass the throttle body. The computer opens and closes the IAC to keep the idle at a set speed.

xttc2000

possibly a vacuum leak.

are your LTFT's still pegged 25?

baddogz28

iTrader: (6)

As far as the fuel trims, I'm not sure, the ses light is off right now, but it comes on sporadically.

xttc2000

we'll scan it sunday if your heading up to the track

glennhl

You should try cleaning the IAC, fixed mine immediately. Only takes about 5 minutes to do.