I have an 06 coupe with a Lingenfelter High Volume (cold air) intake and I need help with a throttle problem.

It actually rained in
California and I found myself turning onto a street where the water was about 10" deep. Sure enough, though I was in the center of the street, I sucked water into the intake and the engine locked. I shut down instantly and pushed the car the remaining two blocks to my destination.

I had the engine purged, oil changed, etc and she fired up. The computer needed to relearn throttle inputs so there was an excuse for some wierdness. But now, a month later, the engine speed does not back down quickly when I come off throttle. With the car in gear, if I come off throttle, it feels like I have cruise control engaged. It takes forever for engine speed to fall. There is no sense at all of engine/compression braking. With the car in neutral, engine speed falls more quickly but no where near as it did before it was locked. The first dealer was unable to diagnose the problem even after the service manager drove the car and said, "that's not right". A corporate Chevy tech put the car on the computer and declared it performs to all design values.

That's not right. Any feedback or suggestions (other than see another dealer)?

dave

 

I have the same problem, no water or any other problems before. It just started to act up in the middle of a long drive. I have it apart for a Maggie install and have not found any problems with anything I have looked at.

 

a snapon scan tool can test in the TAC mode...throttle position commanded,actual throttle position etc

 

I think I read once where water can affect the MAF. When the throttle closes quickly, the MAF should transition proportionately. Might be worth a look.

 

Maybe try this.......

Clean MAF sensor carefully. Then disconnect battery for a min and reconnect. Don't forget to re-index the windows. Don't forget that before you start the car after the battery disconnect make sure everything in the car is off.

Might help.

 

just a thought but maybe your throttle position sensor is going out and not sensing you coming off the gas. just a guess though good luck hope you find the problem quick.

 

Interesting thread. Hope you guys get your issues solved.

 

Take the intake apart and examine the MAF sensor screen, which is on 06 MAFs on the intake side. Perhaps when you ingested the water you ingested some floating debri also, which might be partially plugging the screen. It's worth a look.

 

1 or more of 3 things is/has happened/happening:

1. MAF is dirty. Clean it with non-chlorinated brakes parts cleaner to rule it out.

2. You have a leak in your intake tubing AFTER the MAF sensor. Find leak, fix. Problem goes away.

3. Commanded throttle is not matching actual throttle while your issue is happening. Get someone to connect HP Tuners and log your throttle position when aforementioned events occur. If this is the case, then TPS settings must be altered.

One or more of these WILL fix your problem.