Bmr4life

Updated 2/11/2011

Update, I need some help.

So the car was idling and driving great for the first 150-200 miles. Then after work (2 days after the install) I started up, drove forward about 20 feet, backed up 10 feet, then went to drive forward and it stalled out. RPMs bouncing badly.

Started it back up and it died again while in park. Had to keep my foot on the gas to keep it going the 3rd time I started it.

Since then the car does idle well when sitting at lights. Tries to sit at 750rpm and bounces down to 500rpm.

I've tried changing both idle rpms to 850, but noticed no change.

Just out of curiousty, I've tried it with the AC on Max (which will be crucial in the summer) and it just get worse. Bounces from 750 then immediately to 500 then to 750...


This morning I tried setting the rpms to 950. The in park idle changed, but the drive idle is still sitting at 750.

I'm having these idle issues at cold startup AND after the engine has warmed up. I've read some stuff about the adaptive learning. Could reseting it help this?

Brenspeed recommended that I check the throttle body (I cleaned it no more than 10k miles ago) and buy an Oil Separator.



Original post.

My car is an automatic.

I just had my Detroit Rocker cams installed and they sound great at idle. My question is, how should they sound when you're sitting in drive idling at a light? I ask because the car shakes, but without any proper rhythm and sometime it doesn't shake at all. This is after driving 50 miles home with the Brenspeed tune.

My RPMS sit at 700rpm when idling at light and about 750-800 when in park.

What should I have them set at?

Acerbus 2.0

All I know is that some people with auto transmissions have had problems with lopey cams on deceleration/idle due to setting the rpm's too low. Something about the cams changing the vacuum the trans needs to operate properly or something... They get the flashing O/D light on the dash and the trans stops shifting until you restart the car.

Bmr4life

I don't have any problems like that. Had my wife sit in the car while in reverse with her foot on the brake as I stood outside. Sounds good. Maybe its all in my head.

SpartaPerformance

Yes they will sound off rhythm, especially in drive.

Bmr4life

Just to update this. I am definitely sitting at 750 when idling at a light and somewhere right beneath 750 when in park. I have very little driving issues and really they're not issues. They're more so differences.

There are two big suprises.
#1. The car is a LOT louder now. When the rpms go from 1.5-2k to about 3k or higher, it sounds like a bomb just blew up. The increase in sound level seems exponential. I will have to put some in-line mufflers in to help out the neighbors when I leave in the morning.

#2. The car is very loud at IDLE. Its so funny. At lights, no one gets on my bumper. Everyone has been sitting about a car's distance behind me.

Bmr4life

bump, added some info to the OP.

tx_zstang

Are you using the stock tune or custom tune? You probably need a good tune to account for the cam differences. I use a moderately-aggressive custom-grind cam in my automatic and have no real issues with idling. But the tuner spent a decent amount of time getting it right, too.

Bmr4life

Its the Brenspeed supplied tune.

I cleaned the TB like they suggested. I've done this before and this time there was very little build up. I actually took the TB off to make sure I was getting it spotless.

I also sprayed the mass air sensor that's in the intake.

I then reloaded the tune and its been idling at 750rpms steady. Even when in drive it the AC on. I'm hoping it stays this way.

I have a new problem now that. Going WOT, I high a bad lag at 20mph. Feels like the engine just gives up for a split second then picks back up. I'm wondering if I just need to drive around more for the computer to relearn my driving style.

Simon1

You need a custom tune.