Stall at stop manual trans
Thread Starter
On The Tree
Joined: May 2023
Posts: 116
Likes: 4
Stall at stop manual trans Anyone can give some advise on what I need to change to stop a drop to dead at decel and clutch in coming to a stop. Doesnt seem to matter if I leave it in gear and on brakes or just throw into neutral and on brake to a stop if I don't give it some gas as it comes down it will die on me. Starts back up again but obviously I would prefer to not have to restart at every stop sign or light.
TECH Fanatic
Joined: Jan 2018
Posts: 1,059
Likes: 198
What year?
Did you make any changes before this started, or did it run fine with the current tune and then just randomly started doing this?
Did you make any changes before this started, or did it run fine with the current tune and then just randomly started doing this?
Last edited by NSFW; Jul 15, 2025 at 11:36 PM. Reason: it says manual right in the title...
Anyone can give some advise on what I need to change to stop a drop to dead at decel and clutch in coming to a stop. Doesnt seem to matter if I leave it in gear and on brakes or just throw into neutral and on brake to a stop if I don't give it some gas as it comes down it will die on me. Starts back up again but obviously I would prefer to not have to restart at every stop sign or light.
Thread Starter
On The Tree
Joined: May 2023
Posts: 116
Likes: 4
It is the only vehicle I am working on currently and no vacume leaks to be found yet. It's a swap and first time on the road in this configuration. Motor is out of an automatic suburban. Little bit of cam and exhaust...
Base running air flow or throttle follower, there's also the throttle body cracker table. I think it's called that or something similar, if I saw it I would know exactly but those do help.
I'm sure the tune is set up to manual instead of the factory automatic.
I'm sure the tune is set up to manual instead of the factory automatic.
TECH Fanatic
Joined: Jan 2018
Posts: 1,059
Likes: 198
There's a setting that will allow the adaptive-idle features to kick in before RPM drops all the way down to the idle RPM... set that to at least 500 RPM so adaptive idle will kick at idle RPM + 500 RPM.
I gave my car 2 g/s of throttle follower at 23.5% pedal and higher, and set it up so that it only decays when the clutch pedal is pressed. (Otherwise it decays when you're engine-braking.) Decay rate in gear = 0, decay rate in P/N = 0.015.
I also disabled throttle cracker, partly because I didn't need it anymore but also because it disables adaptive idle, and it was annoying to have my engine surging when I was coasting to a stop.
I also changed the proportional airflow table to add 10 g/s when RPM drops more than 100 RPM below the target. That basically simulates blipping the throttle to stop it from stalling. There's also a setting that limits the amount of airflow that learning can add... I think it was 3 g/s stock and I made it 10 g/s so that the proportional table can do its thing.
A lot of the above basically cheating, but it's all working well, so I'm okay with cheating.
I gave my car 2 g/s of throttle follower at 23.5% pedal and higher, and set it up so that it only decays when the clutch pedal is pressed. (Otherwise it decays when you're engine-braking.) Decay rate in gear = 0, decay rate in P/N = 0.015.
I also disabled throttle cracker, partly because I didn't need it anymore but also because it disables adaptive idle, and it was annoying to have my engine surging when I was coasting to a stop.
I also changed the proportional airflow table to add 10 g/s when RPM drops more than 100 RPM below the target. That basically simulates blipping the throttle to stop it from stalling. There's also a setting that limits the amount of airflow that learning can add... I think it was 3 g/s stock and I made it 10 g/s so that the proportional table can do its thing.
A lot of the above basically cheating, but it's all working well, so I'm okay with cheating.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
On The Tree
Joined: May 2023
Posts: 116
Likes: 4
All sounds like good advice. I will impliment and test drive for logs later today. Got a cut out issue to figure out too. Hard throttle it cuts out not sure rpm seems kind of random engine speed happened a few times drivi g it home last night. Girlfriend followed me and said "it looks happy driving down the road again." Lol whatever that looks like. It has been a while tho and was cool to drive it again just gotta get tune right and tags so i dont get it impounded.
Thread Starter
On The Tree
Joined: May 2023
Posts: 116
Likes: 4
There's a setting that will allow the adaptive-idle features to kick in before RPM drops all the way down to the idle RPM... set that to at least 500 RPM so adaptive idle will kick at idle RPM + 500 RPM.
I gave my car 2 g/s of throttle follower at 23.5% pedal and higher, and set it up so that it only decays when the clutch pedal is pressed. (Otherwise it decays when you're engine-braking.) Decay rate in gear = 0, decay rate in P/N = 0.015.
I also disabled throttle cracker, partly because I didn't need it anymore but also because it disables adaptive idle, and it was annoying to have my engine surging when I was coasting to a stop.
I also changed the proportional airflow table to add 10 g/s when RPM drops more than 100 RPM below the target. That basically simulates blipping the throttle to stop it from stalling. There's also a setting that limits the amount of airflow that learning can add... I think it was 3 g/s stock and I made it 10 g/s so that the proportional table can do its thing.
A lot of the above basically cheating, but it's all working well, so I'm okay with cheating.
I gave my car 2 g/s of throttle follower at 23.5% pedal and higher, and set it up so that it only decays when the clutch pedal is pressed. (Otherwise it decays when you're engine-braking.) Decay rate in gear = 0, decay rate in P/N = 0.015.
I also disabled throttle cracker, partly because I didn't need it anymore but also because it disables adaptive idle, and it was annoying to have my engine surging when I was coasting to a stop.
I also changed the proportional airflow table to add 10 g/s when RPM drops more than 100 RPM below the target. That basically simulates blipping the throttle to stop it from stalling. There's also a setting that limits the amount of airflow that learning can add... I think it was 3 g/s stock and I made it 10 g/s so that the proportional table can do its thing.
A lot of the above basically cheating, but it's all working well, so I'm okay with cheating.
TECH Fanatic
Joined: Jan 2018
Posts: 1,059
Likes: 198
IMO it's worth switching to an OS that has a good XDF if you're tuning yourself. It'll be a pain in the *** to copy the tables over, but you only have to do it once.
Thread Starter
On The Tree
Joined: May 2023
Posts: 116
Likes: 4
Ok I admit that I am ignorant to alot of this stuff but i thought I was stuck with whatever OS was on the PCM from factory. How do I switch and how do I know what is a good switch to make? Copy which tables over from where?
TECH Regular
Joined: Dec 2022
Posts: 444
Likes: 158
The best OS will depend on the computer and your setup.
Some do flex fuel and some aren't compatible with certain dbw pedal/tac
Its been awhile since I've messed with factory pcms but I think the OS i always used ended in 7603...pretty sure
Some do flex fuel and some aren't compatible with certain dbw pedal/tac
Its been awhile since I've messed with factory pcms but I think the OS i always used ended in 7603...pretty sure
I believe you are correct that the 12587603 OS has the most intercompatibility of any of the factory operating systems. It won't work with everything, but odds are better with it than any other random p59 OS. It also has the most fully developed xdf files, as well as some custom code that other people have developed and made available to the community.
TECH Fanatic
Joined: Jan 2018
Posts: 1,059
Likes: 198
What year is the vehicle?
For the P59 PCM, if you have DBW, there's an "early" OS (7603, I think for 04-05) and a "late" OS (I forgot the ID, but I think it's good for 06-07).
If you don't have DBW, then just use 7603, because as mentioned above it has the best XDF. I've also done some reverse engineering on it so if anybody wants parameters that are not in the XDF I can probably find them (no promises, but I can try).
For the P59 PCM, if you have DBW, there's an "early" OS (7603, I think for 04-05) and a "late" OS (I forgot the ID, but I think it's good for 06-07).
If you don't have DBW, then just use 7603, because as mentioned above it has the best XDF. I've also done some reverse engineering on it so if anybody wants parameters that are not in the XDF I can probably find them (no promises, but I can try).
TECH Fanatic
Joined: Jan 2018
Posts: 1,059
Likes: 198
Yes, switching to 7603 will ensure that you have access to every known table. The year of the car doesn't matter much... I had to move an alternator wire when I upgraded my 2002 C5 from a P01 to a P59 but if you've already got a P59 you won't even need to do that - all of the connections will be in the same place.
It'll help to pick a stock .bin file that has the right transmission type, and DBW or not, etc. Hopefully one of these works:
https://github.com/BoredTruckOwner/L...OS/OS_12587603
Or one of these:
https://github.com/Snoman002/Engine-...erating_System
It'll help to pick a stock .bin file that has the right transmission type, and DBW or not, etc. Hopefully one of these works:
https://github.com/BoredTruckOwner/L...OS/OS_12587603
Or one of these:
https://github.com/Snoman002/Engine-...erating_System