1988 R20 TBI High Idle?

[R30 Casey]

Originally Posted by chris989

Casey,
I know this is old and your post is a month ago,,,

Anywhoo,,, I chased a random high issue in my 5.7 tbi forever. I can data log and everything was alway in spec and then while driving it would idle crazy high until i turned the key off and restarted.

It turned out to be a defective TPS sensor. In the garage,, testing voltage it was always good. Even driving it would data log good. I finally caught it one day at a redlight. The TPS value spiked/jumped around and then went back to normal but when it failed for that few seconds it jacked up the computer without throughing a code.

Anyway, new TPS,, no more problem... I plagued me for years.

Need more help just ask,,, I will reply,

Chris

Copy. I appreciate it. I have been chasing an idle gremlin for a while…