just got eng broke in good but sometimes eng dies returning to idle. not sure what to check this is whats been done
standard bottom end
port and polished head
shaved .010
home made intake with k&n filter
new hi flow cat
2 1/2 exhaust with tube style muffler looks like glass pac
runs good had just filled up with 87 octane and ran across shop with dynp on got 149.8 to the ground is this good? or about norm
thanks for any info on dying prob.will help

As far as your Idle problem I'm not sure, althought it could be your throttle cable needs to be adjusted. I wouldnt know off hand since I cant test it. From what it sounds like it has rough idle then falls below 800 RPMS, no consistancy right? As for your Dyno, I'm wondering how much you paid for it. By the way is your Supra a manual or auto? your getting about 150 to the wheels (rounding up of course). The N/A Supra makes 200hp @ the crank, and 187 ft/lbs of torque. If those were your upgrades then I would say that was bad. You should of come up about 10-15 more hp at the wheels honestly.

Check your diagnostic trouble codes:

http://www.cygnusx1.net/Supra/TechTips/engine_error_codes.aspx

Sounds like a bad TPS.

OR, your dashpot is out of adjustment:

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=EC&P=8