Hi, new member working the bugs out of my 87 4wd automatic van. Just failed CA smog with high NO (nox?). I found some vacuum leaks and the broken BVSV. I have diagnostic code 11 blinking. I think I need to replace the Throttle Position sensor.

When I check the timing, the mark travels all over. I think a little travel might indicate a timing chain issue but this travel seems major.
Can a failing TPS make the mark travel?

Any other possibilities?

Thanks for any help!