sputtering at high rpms
 

ok so I have done my research. My car is odd. its a 92 ka24de. When its cold like the first drive of the day it runs perfect. But as it starts to warm up it starts to cut out at hight rpms. Pretty much it feels like its fallin on its face at 3900 rpms. And mean while the battery light is on and flashing when you go higher in rpms. ( kinda like a blinker) I have had the alternator tested and the starter tested. I have gone through and scrubbed and cleaned all the grounds.. Whats next?!

check for loose wires or a loose connection

already did.. Not that.. Do you think it could the alternator going? but it only does it on high rpms

Alternator is starting to fail. Had the same thing happen to me a while back.

also check the ignitor.
my 92 that i sold my brother in law had this problem. he said it was losing power and he tried all kinds of stuff.
finally one of his mechanic buddies just slapped a random ignitor (from a ford?) into the 240 and it ran like a bat out of hell (for a stock KA anyways).

hope this helps.