I recently purchased a SCT3 and custom tune from Brenspeed. I have a 05GT with cold air intake,headers,off road, flowmasters and I ran it with the factory tune for several years until recently. I got the tuner, downloaded the tune and car started very roughly on first start but within about a minute the idle settled down and run normal. First drive was eye opening to say the least. I got a 93octane tune setup with the offroads and the flowmasters and the cold air intake. I think the tune is right because it runs super strong now but the first start worries me a little. Having driven the car for 2 days now it seems to be getting better, the rough start, but it is still there. It takes about 30 seconds or so upon start up for the car to find a smooth idle but once it does the difference is pretty amazing. Anyone else have this problem, does it get better with time or is there a problem with the tune? Thanks for the help and this forum has saved me alot of time and money in the past! Thanks

 

While I don't know for sure if there's a problem or not, I know that apparently these cars have to learn their idle after a new tune or something. Something to the extent where after loading a new tune you're supposed to let it idle for 5 minutes. I'd say just let it idle and learn, and it should get better. Could always contact brenspeed and ask them, I'm positive they'd be more than happy to help.

 

How did you run your car on the factory tune with headers, intake, and o/r pipes?

I can't even run mine with just an intake without a tune.

 

Yeah dude those are mods I wouldnt ever think about not running a tune with. You werent throwing all kinds of CEL's?

As for the first start, I would worry about it. When you first upload a new tune the car needs to COMPLETELY learn the new tune. After a few days the car will feel even better.

 

I was using mil eliminators in the back o2 sensors and the air restrictor in the cold air intake. Yea I was pressing it but I am not hard on a car. Car runs great now, has a nice snap in the throttle and I can really feel the differance and now I am not afraid to really hammer the throttle. So what I am hearing is that it will get better after the computer learns the sensors and setting over a period of time. Right?

 

Yeah dude everything will be fine, it just need to relearn the tune. But this only happened on the first startup right? If this is every startup since you uploaded the tune than no I would call.

 

Rough idling is somewhat common following a retune or after resetting the Adaptive Learning. It usually smooths out after about 20-50 miles of driving or a few days. If it was persisting, I'd suggest checking with Brenspeed so they could tweak the cold-start.

 

Well I have driven the car for a couple days now and still the problem is still there. I am being told it is a cold start problem but it does it even when the car is warm like when I stopped for gas last night. 30seconds to clear out and settle and then all is fine. Calling Brenspeed in the morning.

 

Yeah, I wouldn't say that's normal. Good luck and let everyone know how it goes.

 

Yeah if it happened for just the first start with the new tune it would be normal. Didnt know it was persisting. Let us know how it goes with brenspeed.