Tune Issue?
02-03-2010, 07:03 AM
#1
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Tune Issue? I just installed some longtubes, and a ported ls6 intake and a ported and polished throttle body. Now my car is idling really rough and high... like above 1k RPM. and when the car is warmed up and I just TAP the accelerator, the RPM shoot up to like 2-2200k and hang for a second before slowly declining to about 1100k. Does this sound like a tune issue or something else? I also tried changing the throttle positioning sensor to no avail. A local shop told my that when the throttle body is altered in any way the car needs to be tuned and thats it. But I would like to be certain before I let him tune my car
02-03-2010, 07:24 AM
#2
Too much airflow around your throttle blade; I doubt software can fix that 
CLOSE the throttle blade's minimum airflow screw (T15 screw commonly mistaken to be an "idle screw) on the throttle body linkage about a half-turn. At first, the car may not want to idle but it will re-learn it. If the person really out the TB around the blade, it may just be ruined. At any rate, the fix is limiting the airflow in at 0% throttle.
CLOSE the throttle blade's minimum airflow screw (T15 screw commonly mistaken to be an "idle screw) on the throttle body linkage about a half-turn. At first, the car may not want to idle but it will re-learn it. If the person really out the TB around the blade, it may just be ruined. At any rate, the fix is limiting the airflow in at 0% throttle.
02-03-2010, 01:31 PM
#4
He said it was idling rough at over 1K RPM? Are you sure it isn't an intake leak? Kinda hard to tell on our cars, but you might want to feel around the back of the intake and make sure you didn't pinch something when sitting the intake back down, and that it's fully seated like the front. Also make sure you didn't forget to reconnect the vacuum lines and stuff, but that shouldn't make it idle rough.
02-03-2010, 08:56 PM
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No, the intake came with the trottle body and it was done professionally (which doesn't mean it was done correctly) but it looks like the blade seals well when it's closed. I'm beginning to think that it's a computer problem..
Here's another thing i'm noticing. If I even increase the throttle the smallest amount, (seriously, i'm talking about pushing the gas pedal down like a quarter of an inch) the rpm will go up to about 2k and stay there for like 5 secs and come back to like a thousand. Another strange thing is that i'm MOVING and I take the car out of gear and coast, the rpm will stay at around 1800-2k UNTIL I STOP.
I have no idea what's going on.. I did feel around the back of the intake for things underneath, or something i didn't plug in. This sounds crazy but i'm just telling it like it is.
Tomorrow i'm going to put the stock throttle body back on and see if I can rule out the throttle blade issue
Here's another thing i'm noticing. If I even increase the throttle the smallest amount, (seriously, i'm talking about pushing the gas pedal down like a quarter of an inch) the rpm will go up to about 2k and stay there for like 5 secs and come back to like a thousand. Another strange thing is that i'm MOVING and I take the car out of gear and coast, the rpm will stay at around 1800-2k UNTIL I STOP.
I have no idea what's going on.. I did feel around the back of the intake for things underneath, or something i didn't plug in. This sounds crazy but i'm just telling it like it is. Tomorrow i'm going to put the stock throttle body back on and see if I can rule out the throttle blade issue
