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Stl-986 · 07-25-2021, 04:26 PM

That's just it, dont have strong vacuum at idle. I have great vacuum when the rpms are high, but think I absolutely have a vac. leak.

I can get vacuum up to 20hg around 3k rpm, let off the throttle and watch to drop slowly. Seems to drop faster when all the fans kick in.

Misfires did come back after an hour. They reset themselves to 0 and then when the front fan kicks it they start to climb up again. They are not happening anywhere near like they were before though.

Didn't grab a chart, but I started to graph voltage the last time and noticed that it is around 13.5 and then when the engine fan kicks in it goes to down to 13.2 for a bit, then when they front cooling fans kick in it goes down to 12.8 but does start to climb back up to around 13.4.

I'm just rambling, but the past 2 years I have been working on this issue I found 1 person who was having similar misfires and what fixed it was a new alternator. Electrical issues can cause some weird things to happen but I have kept it in my mind since seeing it

AC was off

Here is the video:
https://youtu.be/XqlX4KJZ24U

07-25-2021, 04:26 PM	#66
Stl-986 Registered User Join Date: May 2017 Posts: 1,182	That's just it, dont have strong vacuum at idle. I have great vacuum when the rpms are high, but think I absolutely have a vac. leak. I can get vacuum up to 20hg around 3k rpm, let off the throttle and watch to drop slowly. Seems to drop faster when all the fans kick in. Misfires did come back after an hour. They reset themselves to 0 and then when the front fan kicks it they start to climb up again. They are not happening anywhere near like they were before though. Didn't grab a chart, but I started to graph voltage the last time and noticed that it is around 13.5 and then when the engine fan kicks in it goes to down to 13.2 for a bit, then when they front cooling fans kick in it goes down to 12.8 but does start to climb back up to around 13.4. I'm just rambling, but the past 2 years I have been working on this issue I found 1 person who was having similar misfires and what fixed it was a new alternator. Electrical issues can cause some weird things to happen but I have kept it in my mind since seeing it AC was off Here is the video: https://youtu.be/XqlX4KJZ24U __________________ 2000 Boxster Tiptronic 2003 Boxster 2003 996 C2 Cab 2002 996 (SOLD) 1986 944 (gone but missed)