Lock Up Issues after installing 3600 stall...HELP!
Thread Starter
Staging Lane
Joined: Aug 2019
Posts: 78
Likes: 40
Lock Up Issues after installing 3600 stall...HELP! Hi Guys,
I recenting had a 3600 FTI stall put in my 98' Trans Am w/27,000 mi. I had a local speedshop do the install followed by a dyno tune. Everything seemed great with the car when I took it home, stall totally changed the driving experience for the better! However, I've now been experiencing some intermittent issues with lock up. The car will be totally fine cruising around and then, for some reason, will bump out of lock up with little to no change in engine load then not want to drop back in. I went back up to the tuner to show him what it was doing and, of course, we drove around for 20mim with his computer hooked up and car acted perfect.
Told him I'd just keep an eye on it for a couple weeks and see how it went. The car is not a daily driver for me so doesn't see much rode time. I did take a 60mile road trip yesterday though and had ZERO issues curising @ 65mph for the first half of the trip. The car sat for 45min or so before the return home and began kicking in/out of lockup for a good 15-20mi @ the same crusing speed on the same highway. Then, after slowing down to get through a short stretch of highway through a small town, it acted totally fine again for the last 10mi on the highway @ the same crusing speed.
The car does have a few other bolt-ons (LT's, ORY, Catback, LID) and I did install a tranny cooler but can't imagine that would make a difference here.
It makes absolutely NO sense to me but just trying to gather any/all info I can to take back to my tuner. Any help/feedback would be much appreciated! I did read through the sticky on Trans tuning but its all over my head.
Thanks!
-Joe
.
I recenting had a 3600 FTI stall put in my 98' Trans Am w/27,000 mi. I had a local speedshop do the install followed by a dyno tune. Everything seemed great with the car when I took it home, stall totally changed the driving experience for the better! However, I've now been experiencing some intermittent issues with lock up. The car will be totally fine cruising around and then, for some reason, will bump out of lock up with little to no change in engine load then not want to drop back in. I went back up to the tuner to show him what it was doing and, of course, we drove around for 20mim with his computer hooked up and car acted perfect.
Told him I'd just keep an eye on it for a couple weeks and see how it went. The car is not a daily driver for me so doesn't see much rode time. I did take a 60mile road trip yesterday though and had ZERO issues curising @ 65mph for the first half of the trip. The car sat for 45min or so before the return home and began kicking in/out of lockup for a good 15-20mi @ the same crusing speed on the same highway. Then, after slowing down to get through a short stretch of highway through a small town, it acted totally fine again for the last 10mi on the highway @ the same crusing speed.
The car does have a few other bolt-ons (LT's, ORY, Catback, LID) and I did install a tranny cooler but can't imagine that would make a difference here.
It makes absolutely NO sense to me but just trying to gather any/all info I can to take back to my tuner. Any help/feedback would be much appreciated! I did read through the sticky on Trans tuning but its all over my head.
Thanks!
-Joe
.
Moderator
Joined: Aug 2010
Posts: 7,322
Likes: 528
From: Ann Arbor, MI
A stall TC can cause the PCM to record bogus cylinder misfire codes. IIRC this can then cause the PCM to not command TC lockup. The fix is for the tuner to desensitize the misfire detection.
Banned
Joined: May 2020
Posts: 252
Likes: 84
From: USA
For that converter the misfire tables need to be adjusted or just maxed out. Some people also disable P0300.
I have a scan file showing multiple misfires in real time. Enough to make the TCC disable, but not enough to throw a code or even a pending code. If it doesn't throw a code it will just not lock up at random.
It's a false misfire due to the change in rotating mass. There are three tables, one for low rpm, medium rpm, and high rpm.
Could also be the tuner set the lock/unlock speeds too close. Without seeing the tune file it's all a guess.
I wouldn't go pulling the trans to check the o-ring, change random parts, nothing. First place to check is the tune.
I have a scan file showing multiple misfires in real time. Enough to make the TCC disable, but not enough to throw a code or even a pending code. If it doesn't throw a code it will just not lock up at random.
It's a false misfire due to the change in rotating mass. There are three tables, one for low rpm, medium rpm, and high rpm.
Could also be the tuner set the lock/unlock speeds too close. Without seeing the tune file it's all a guess.
I wouldn't go pulling the trans to check the o-ring, change random parts, nothing. First place to check is the tune.