Runs but falls on face when warms up

[slipknot51]

So i got My 91' ss finally running after dealing with redoing wiring. And now i got it started and it runs until it gets to op temp and then starts to run ruff like it might be missing on a cylinder and try's to kill it self and if you give it gas it drop down to idle and say's there for a few seconds and then it just dies and it doesnt want to restart until it cools down. I have replaced the crankshaft sencor,fuel pump and put in a new fuel filter.I am thinking maybe it might be a issue with an IAC, or maybe when it warms up something like vacuum lines might open or spread and leak. I know i have talked to one of my friends and he said maybe the turbo might be seaseing up when it gets warm which i dont think that it would i check it and i dont have any excessive axial or radial play when its cold but im sure it doesn't matter either way. I know that i have a check engine light and the codes are 12 and 22 I know that 22 is a knock sencor code but i have that diconnected since im still working on minor wiring aka replacing the connector. If anyone might be able to point me in the right direction it would help Thanks,

[Legacy777]

For temperature related issues I highly suggest replacing the coolant temp sensor. It's relatively cheap, about $20 and can cause lots of issues with how the car runs if it's not working. Typically it does not throw a code for being bad, and really doesn't test well either. So I usually just recommend replacing it.

[slipknot51]

So update on the subaru Issue i replaced the ect and changed the oil and its running alot better now but still is having issue if you were to take and rev the engine above about 3k and let off the engine tries to idle kind of stumbles and some times dies. Im wondering if anyone might have an idea why it might be doing it. I know that if i try to lower the rpm's down insted of letting it drop i can usually keep it running it. It just run's kind of crapy for a few seconds then goes back to being fine. I dont know a 100% on this but i do have the bov going 100% to atomisphere insted of recerculating which is due to the intake breaking.

[lucas]

IACV, might cause problems.

[Legacy777]

If you have the BOV going to atmosphere, chances are that is some of the problem. Check to make sure it is not leaking air when it's idling or when rpms drop. If it is, you'll need to fix the intake/BOV setup so it is not leaking air.