cole3

I've had my 2006 z06 for 3 weeks as of today. it is bone stock and has about 68k miles.
it likes to hold whatever rpm it's at when I take it out of gear for a few seconds then it will drop down to normal idle slowly.
I cleaned the MAF sensor and the issue still persists so I was thinking there must be a vacuum leak somewhere and was wondering if anyone had a diagram of all of the vacuum lines or if anyone knows of another cause.
Thanks!

Bill Dearborn

If you had a vacuum leak you would have a CEL. How are the O2 sensors? Maybe one of them is getting ready to fail.

Bill

American Heritage

MAP sensor

wjnjr

Interesting. Is it possible to have a bad MAP sensor without a CEL and/or a DTC?

Chris Bert

Would the MAP sensor also cause this problem. If I'm in a drive thru line and I try to inch forward just by taping the gas, RPMs will rev to 1200 and slowly come back down. Never really thought anything of it until I read this thread

cole3

this also happens to me.
does the ls7 have both a MAF & MAP?

cole3

I have not checked the o2's but just learned how to check them so I'll give that a go once I dig out of this homework hole lol

50 4Ever

This is normal in the C6's with manual transmissions, didn't do it in the C5 I had. Talked to my tuner about it and he said it was throttle follow-on, or something like that. It is particularly bothersome on the road course after a downshift, the RPM's won't start to come down for a few seconds.

This was also mentioned at a tech forum at the Black Hills Corvette Classic 5 or 6 years ago, I think they said the two major reasons it was done was fuel mileage and it was easier on the drivetrain.

MarkC

I had the same problem and when I had my heads done by Vengeance I mentioned this to Mike, the tuner. He greatly improved the problem but it still is not like the C5 or a carb. A good tuner can improve the issue.

AZDANZ06

Yes.

Here is a link for the MAP Sensor:

http://www.gmoutletparts.com/oe-gm/12615801

Michael_D

The OP said........... "it likes to hold whatever rpm it's at when I take it out of gear for a few seconds then it will drop down to normal idle slowly."

That's not normal. I'm not sure what could be causing the "few second" delay. I was thinking the TPS (throttle position sensor) may need to be recalibrated, but that was just a guess. Kohle recommends looking at the MAP sensor, and that may be the issue.

cole3

now that you mention the TPS, that seems like the most likely suspect.
a week ago I started the car and it had some random Misfire and NO throttle response at all along with a CEL and reduced engine lower message.
I disconnected the battery and reconnected it and also disconnected and cleaned the TPS then gave it a go again and it was resolved and the issue has not come back.
the fact that I've already had an issue with the TPS raises some concern that it may be the cause.

AzDave47

Probably not your issue, but something to be aware of re MEF problems:

https://www.corvetteforum.com/forums...d-effects.html

cole3

if it helps to diagnose it at all, after I give it some ****, it has a weird idle where it'll randomly rev from 500ish-1000ish a few times for a few seconds.

NORTY

Check your coolant temp when this happens again.

cole3

196°F just now with ambient air around 40°

cole3

interestingly enough, my MAF just had an M on it. just one letter which could very well be a "weak" sensor compared to one with a letter & number.

cole3

borrowed a re manufactured MAF from an O'Reillys my buddy manages and the car still has the same rough idle for a few seconds after some abuse.

Michael_D

Try swapping the MAP sensor like AH suggested.

AZDANZ06