Fluctuating idle
Hi. I have a Hyundai Santa Fe 2009 3.3L model with a fluctuating idle, stalling issues and sometimes the engine switches off while driving, but starts up right away when restarted. Ran a scan as shown in the video below to monitor the TPS (blue line), Pedal sensor (green line), MAF (red line) and the MAP (brown line) sensors while the engine was running (beginning from idle to me depressing the accelerator up to 2,600 rpms and back down).
I noticed the MAP was highly unstable. Is that normal?
At point 318 on the horizontal axis, the engine switched off on its own, and both the TPS and MAP spiked (not sure if that’s what it’s supposed to do)!
- What is the relationship between the MAP and the TPS?
- Does the TPS determine the MAP reading or vice-versa?
- Can a MAP reading indicate engine compression loss?
Thanks
Seems like a vacuum leak to me. Were there any check engine light codes?