An eldery neighbor of mine asked me to have a look at her 1997 Nissan Sentra because the CEL came on. It is a 1.6L I4 DOHC 16V engine. I got code P1110, variable valve timing solenoid. I removed the solenoid, cleaned it, replaced the o-rings, and reinstalled. Changed oil, cleared code and it ran for about 10 minutes and CEL came on. Same code. Checked VVT solenoid. It cycles when 12 VDC is applied. Have 12 VDC on brown wire when key is in run position. My first question is this valve position sensative when installed? There were no marking on it. Any ideas what to check next?