catalyst

Hello. I have a ’96 with a MS2 DIYPNP. The engine is currently stock with a few exceptions, running Flow Force 640cc EV14 injectors and the MS2 has and external map sensor. Still have the stock AFM in place and using that MAT sensor. Also an innovate mtx-l. I’ve been slowly working on tuning this guy for the last couple months. Bit of a learning curve but it’s coming along.

I have run into an issue that I can't seem to resolve with the provided tuning options available. If anyone would be willing look at these logs and offer opinions I would be grateful. The issue occurs after a restart with engine at temp(hot). Initially I identified the issue as a lean idle, afr 17+ on hot restarts. This seems to be a well-documented problem, most were saying heat soak of the MAT sensor or NB’s with return less rail were having their own set of issues. The strategy that seemed to work for people with NA was increase fuel till sensor temps dropped. Using the MAT correction table didn’t seem like the best option to me. So I ended up using ASE and have added 2500 cycles to ASE and richened up the curve for CLT temps above 170. With this the car idles decent after a hot start albeit 11.5 to 12 afr for the first min or so. As soon at the ASE fuel correction tapers to around 14.0 the idle goes to crap, stumbling and almost dying in some cases. Lots of idle variation and poor afr stability. Off idle things smooth out considerably; afrs seem normal, I would say smooth operation in general with load. It just can’t seem to handle idle and never seems to stop struggling unless the car sits overnight. I have logged the issued and see a difference in the data when it's hot, lots of small oscillations in several sensor readbacks makes me think I might have some electrical issue. I am seeing battery voltage also jumping quite a bit. Logs with title "weird noise" will show this toward the end

If I start up the car from full cold it runs well enough. VE table is not perfect but close. EGO is still disabled. The idle control valve is in closed loop and controls idle decent if the car was started cold. In the data logs there are two cases. First log is after I have driven the car around for 20 min and let it sit and idle and is running well at this point. Idle is tight and fuel is in check maybe a tad rich.

Turn off, wait 10 min. The other 4 logs begin now, Upon restarting it’s like a completely different car. I think the logs will show. Its honestly a little scary at some points. My feeling after a couple weeks trying to analyze the prob is that something apart from the tune is really having trouble in this situation. Any ideas on what is causing this? Let me know if you want some details. I have attached 5 logs and my tune, Bad 1-4 is respective to time acquired. Hope this is not too much. The last log probably shows the most protuberance. I'm kinda stumped at the moment...