I didn't realize I needed a tune!
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
I didn't realize I needed a tune!
When I installed my factory 806's back on a couple of days ago after having a 5 angle valve job. I thought my computer would relearn the new fuel settings and such but it didn't. Jason at Texas Speed and Performance emailed an updated tune to load and it fixed the idle issues perfectly.
Faerman machine shop in Houston told me the heads would flow much better, but I had no idea they would have such a big impact on the cars old tune.
Anyway, A big Thanks to Dennis Faerman(Faerman's) and Jason at TSP!
Faerman machine shop in Houston told me the heads would flow much better, but I had no idea they would have such a big impact on the cars old tune.
Anyway, A big Thanks to Dennis Faerman(Faerman's) and Jason at TSP!
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
Back to square one, The first test ride was perfect and I was very happy! But upon starting the second ride to town, the car reverted to running like it did before with hanging rpms until coming to a complete stop.
Burning Brakes
Joined: May 2011
Posts: 1,216
Likes: 56
From: Houston Texas
What are you using to "upload" the tune? HPtuners, etc.? Did you reset your fuel trims after uploading the new tune?
The hanging idle is from too much air in your base idle airflow table. When you come to a complete stop, adaptive idle kicks in and forces it back to targeted idle speed by killing timing and closing throttle/iac.
This table needs to be correct, or idle trims will carry over to the next startup (i.e. negative trim at shutdown will result in negative trim at startup, and vice versa). Too negative at startup, and idle will stumble when coasting until enought time has passed for idle trims to catch up. Too positive, and idle will hang until trims catch up. I don't see how it can be done accurately without the tuning device/tuner/car all being in the same place. It also needs to be done from cold startup temperatures, to hot temperatures.
The hanging idle is from too much air in your base idle airflow table. When you come to a complete stop, adaptive idle kicks in and forces it back to targeted idle speed by killing timing and closing throttle/iac.
This table needs to be correct, or idle trims will carry over to the next startup (i.e. negative trim at shutdown will result in negative trim at startup, and vice versa). Too negative at startup, and idle will stumble when coasting until enought time has passed for idle trims to catch up. Too positive, and idle will hang until trims catch up. I don't see how it can be done accurately without the tuning device/tuner/car all being in the same place. It also needs to be done from cold startup temperatures, to hot temperatures.
Thread Starter
Le Mans Master
Joined: Nov 2009
Posts: 6,119
Likes: 156
From: Huntington tx
What are you using to "upload" the tune? HPtuners, etc.? Did you reset your fuel trims after uploading the new tune?
The hanging idle is from too much air in your base idle airflow table. When you come to a complete stop, adaptive idle kicks in and forces it back to targeted idle speed by killing timing and closing throttle/iac.
This table needs to be correct, or idle trims will carry over to the next startup (i.e. negative trim at shutdown will result in negative trim at startup, and vice versa). Too negative at startup, and idle will stumble when coasting until enought time has passed for idle trims to catch up. Too positive, and idle will hang until trims catch up. I don't see how it can be done accurately without the tuning device/tuner/car all being in the same place. It also needs to be done from cold startup temperatures, to hot temperatures.
The hanging idle is from too much air in your base idle airflow table. When you come to a complete stop, adaptive idle kicks in and forces it back to targeted idle speed by killing timing and closing throttle/iac.
This table needs to be correct, or idle trims will carry over to the next startup (i.e. negative trim at shutdown will result in negative trim at startup, and vice versa). Too negative at startup, and idle will stumble when coasting until enought time has passed for idle trims to catch up. Too positive, and idle will hang until trims catch up. I don't see how it can be done accurately without the tuning device/tuner/car all being in the same place. It also needs to be done from cold startup temperatures, to hot temperatures.
I have HP Tuners and don't know a dang thing about what to change. That's why I asked Texas Speed to email a tune and I would upload it.
It ran fine one time only then reverted back to hanging rpms the second time. I tried to reload the tune but it didn't have the same effect it did the first time. It still surges a little at idle and once the car rolls it revs to 1100-1500 rpm and hangs there till I stop again.
Burning Brakes
Joined: May 2011
Posts: 1,216
Likes: 56
From: Houston Texas
If you feel up to making some adjustments yourself, shoot me a pm with your email and I will send a couple things you can do for properly finding the idle airflow values using the scanner function. It's known as the "russK idle config" on the hptuners forum, not taking any credit here. Basically, you start it cold in the morning and log until hot and then copy/paste your new values in to the tune.
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