Pontiac G8 Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
409 Posts
Discussion Starter · #1 · (Edited)
Hi all, I’m having a strange issue with my GXP A6 car with tuning installed. I have the VCM intake, longtube headers and no cats and a Borla. I’ve emailed the folks that wrote my tune already; just looking to see if anyone has seen this.

With the tune installed, I’ll sometimes be coming to a stop. Just before I come to a stop, the car will act like I slammed on the brakes or downshifted manually. It noses over and I go forward in the seat despite not putting any more pressure on the brake pedal. I’ve put it in sport mode to see if it’s downshifting to first when it does this. It’s already in first though.

I went back to stock for about a week and it didn’t do this at all. Still waiting on a response from the tuner as I only emailed them today. Any ideas though? I thought to have the dealer confirm the trans fluid is full based on my Camaro pan. Could it be a combination of this and whatever the tune is doing causing the TC clutch to lock up?
 

·
Premium Member
Joined
·
9,088 Posts
Reads like the issue is
...With the tune installed, I’ll sometimes be coming to a stop. Just before I come to a stop, the car will act like I slammed on the brakes or downshifted manually. It noses over and I go forward in the seat despite not putting any more pressure on the brake pedal. I’ve put it in sport mode to see if it’s downshifting to first when it does this. It’s already in first though.

I went back to stock for about a week and it didn’t do this at all. Still waiting on a response from the tuner as I only emailed them today...
Was the ecm, tcm or both tuned? Reads like the issue lies within the tune. If it were a low fill issue, then such would persist upon returning the car to stock.
 

·
Premium Member
Joined
·
9,088 Posts
^^^ This or find another tuner. Just saying.
 

·
Dazed - Confused
Joined
·
508 Posts
What tuning software is your tuner using? HP Tuners offers the most parameters. I switched tuners and tuner software because of this some years ago, when my G8 with cam & Circle D would occasionally stall out when braking. Patrick G and HP tuner software solved my issue quickly.
 

·
Registered
Joined
·
409 Posts
Discussion Starter · #7 ·
Sorry didn’t get notifications on this thread. It’s the MyCal product but I need to double check what they use behind that.

After some more testing, I realized what the car does feels exactly like if I brake and just before I come to a stop, shift manually into 2nd. Does it both in normal and sport mode but never if I’m in sport and manually force to 1st.

it sort of went away when I changed from my winter wheels back to OEM summer.
 

·
Registered
Joined
·
409 Posts
Discussion Starter · #8 ·
Update on this. I contacted LMS and explained what was happening. They checked the file they sent me and said it’s their 3rd file they’ve released for mail order tunes. Not many people have used it and the tech thought it was a file they created to work out some issues for someone. They sent me their 2nd release file that the majority of their customers have and I loaded it. So far so good.
 
1 - 8 of 8 Posts
Top