why does it die when coming to a stop?

[spy2520]

title fairly self-explanatory. Decent size cam in an ls11. Automatic. Stall converter, aluminum flexplate.

Just trying to get thoughts on why this happens so i can investigate it in the tune.

[spy2520]

Zeroed out the direct airflow correction table. Seems to have helped. I think the corrections were compounding the issue, either correcting too slow or correcting down too much.

Still experimenting.

[joecar]

Which columns in B4515 did you zero...?

[spy2520]

All of them for now.

[spy2520]

Tried zeroing spark idle corrections first. Problem was unchanged. So I reversed that and did direct airflow.

[odd boy]

please post file and datalog as well as mods.

[joecar]

+1 please post files.

[RADustin]

sounds like you need more base airflow. this is what my truck was doing before I added air flow. I did RAFIG then added a bit to it.

I did have an issue afterwards where the truck was learned down too far so I think it's best to make sure the values to add learned airflow are larger than subtracting. this way it learns up faster than it learns down.

[spy2520]

I'll look into that. Logs coming soon, been catching up with work.

[RADustin]

turn rolling idle off or at least raise the speed that is considered 0 or whatever. then log coming to a stop.

you will probably see RPM just die off while MAP slowly rises to atmosphere.

are you electric throttle or cable?

[spy2520]

Cable throttle. Mods are vrx5 cam, FAST102. 1.875" headers/3" x-pipe, 3600 stall converter, lightweight aluminum flexplate.

[spy2520]

Sorry for the delay, here is the latest log and tune. As you will see the idle section has gone through various iterations. Some most likely in error due to me falsely thinking i fixed it only later to realize the problem is still there.

You don't have to go far in the log before it stalls, i think it was within the first minute or two. It took 3 logs for it to have issues though, the first two logs i did had no problems whatsoever.

[RADustin]

your IAC counts are very high. I would try cracking the throttle a bit to get the counts down to 30-40 with the course adjuster screw. you could drill the TB as well if you are brave.

I also thought for cable cars that TPS should be zero at idle. Yours pops up to .4% and dies- maybe the idle controls are going in active? Try a TPS relearn.

You should be adding spark as well as idle drops. It doesn't look like this is happening. I understand the air flow is decaying taking spark with it- but you hit 0° of timing before RPM totally died.

I didn't look at your tune yet- I'll look later. just going through your log.

[spy2520]

I dunno whats going on with the timing. I'll have to look at that.

[spy2520]

When you say iac counts of 30-40, is that P/N or in gear? (its an auto)

[RADustin]

In gear. have you done running airflow in gear? (RAFIG)

[spy2520]

I did several iterations of it, including logging MAF airflow instead of the standard procedure.

Probably need to do it all over since opening the throttle a little more.

[spy2520]

Looks like my problem is definitely related to throttle fluctuating between 0 and .4% when slowing down. I've done a TPS relearn though. And I'm pretty sure all my idle tables are set for a TPS of 1.1 or below to be considered idle.