Here we go again...
 

Well I am putting my supra back together again this weekend this time with the hks metal head gasket along with the arp bolts. Wish me luck.

*Luck*

:offwall:

Well its back together and runs but it runs bad It need s aO2 sensor I found out hopefully thats all it needs!

good luck with it:bigthumb:

Well crap... It wasnt the O2 sensor... What do you guys think? It runs but the idle is VERY jumpy and sometimes it dies. It idles jumping from like 800-1100 RPM. i have tried everything I can think of. Please help.

is there a check engine light? if so do a diagnostic

oh shit do a diagonstic anyways

Sounds like some sort of intake leak. Put a vacuum guage on the hose that goes to the cruise control and see what the guage reads. If its low, jumpy or steady.

Hey bro next time do a search I have the same problem:
http://www.toyota-supra.info/forums/...ead.php?t=5714
Couple of things could be the problem:
AFM is mucking up, You have a leak in your preheater house, Do a diagnostic.
http://www.toyota-supra.info/forums/...read.php?t=323
*edited becuase I saw you checked the o2 sensor already.

sounds like you having problem with your timing mark...