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I bought an 07 corvette about a month and a half ago and absolutely love it. It’s cammed, ported heads, intake manifold, etc. But since I’ve had it I’ve had a weird high idle issue. When I first turn the car on it acts totally normal and idles around 700ish once warmed up, but once I hit the gas to get moving the car jumps forward and then sits on its own basically like I have cruise control, and stays just under 2000 rpm. If I’m in first gear (same issue in every gear) I can slow down when pressing the brake but once I let off it once again jumps forward and continues at that speed. I thought it could be a tune issue. The guy who built the car said it was dyno tuned after all the mods were installed. I’ve replaced the mass airflow sensor, took off the throttle body and totally cleaned it. And I’m sitting here about to order a new TB but wanted to make a post on here first to see if anybody had any idea what the issue may be. I’m willing to try just about anything. I also bought a Diablo sport t2 to datalog so I can get a new tune if necessary.
Could be the tune...check Idle minimum final airflow. Symptoms of the values in this table being too high are idle staying high after revving the engine or decelerating to a stop.
Very likely something like a vacuum leak is causing the high idle. That, or it's something not correct in the tune.
if it was a vacuum leak wouldn’t it always idle high though? I may be wrong I’m not trying to sit here and prove you wrong or anything I just thought that a vacuum leak would be constant. Also I forgot to mention in my first post that the idle jumps up to 2000 rpm when slowing down if the car is in neutral and my foot it off the clutch. But as long as I keep the clutch pushed in until I come to a complete stop then I don’t have any issue.
Could be the tune...check Idle minimum final airflow. Symptoms of the values in this table being too high are idle staying high after revving the engine or decelerating to a stop.
I’m not too sure what you mean by this… could you explain any more? Sorry😬
Could be the tune...check Idle minimum final airflow. Symptoms of the values in this table being too high are idle staying high after revving the engine or decelerating to a stop.
He's talking about the table below. The tuner should have adjusted this table for idle and driveability.
He's talking about the table below. The tuner should have adjusted this table for idle and driveability.
okay thank you! I think I’ll try to find a good tuner then. If anybody has an suggestions that would be great. I’m not looking for any more power than I already have because for now I’ve got plenty. Just somebody that will be able to fix some drivability issues!
So I decided to just go ahead and order an hp tuners device and went to check the table y’all were talking about. But my problem is when it comes to tuning I’m in wayyyy over my head lol. I attached a picture of my table. If anybody any idea about this being too high that would be great. Any information is more than I have.
Also try the HP tuners forum. There you can download a stock tune or tune for a car similar to your mods and use the HP Tuner “compare” menu option to see areas that are different. If all else fails just begin by removing 20%(Multiply by .80) from the cells that you are having a problem with.. Reflash and give it a try. Back up your current tune in case you need to restore. This is how you begin to learn how to tune. If it is still over revving try another 15%. It’s a pretty safe table to experiment with and if it doesn’t solve your problem you can return it to the way it was and read up on some of the other tables such as timing decel, idle decel, or DFCO. The compare function vs. stock tune will highlight what tables have been changed.
Also try the HP tuners forum. There you can download a stock tune or tune for a car similar to your mods and use the HP Tuner “compare” menu option to see areas that are different. If all else fails just begin by removing 20%(Multiply by .80) from the cells that you are having a problem with.. Reflash and give it a try. Back up your current tune in case you need to restore. This is how you begin to learn how to tune. If it is still over revving try another 15%. It’s a pretty safe table to experiment with and if it doesn’t solve your problem you can return it to the way it was and read up on some of the other tables such as timing decel, idle decel, or DFCO. The compare function vs. stock tune will highlight what tables have been changed.
Thanks man! Over the past week I’ve been learning tons about tuning. And I’m just now starting to figure out what everything does (there’s way more to it than I thought). I seemed to have fixed 90% of the issues. Still working on fine tuning though. I’m pretty sure the previous owner only used the car on the drag strip so I’m just working on tuning more for daily driving.
Possible throttle body issue
