- Fuel pressure regulator
- Air mass sensor (thanks Abscate)
Thanks for the suggestions.manovlov wrote: ↑10 Jan 2026, 10:26 I had a similar issue few years ago. It was the camshaft pulse sensor. It solved the problem. By the way, these are the parts I've also changed (i was on my "stage 0" reconditioning my car just after bought it - belts, filters, all fluids...).
camshaft pulse sensor.pngFuel pressure regulator.png
- Fuel pressure regulator
Air mass sensor.png
- Air mass sensor (thanks Abscate)
[listThrottle position sensor[/list]Throttle position sensor.png
You may also check the temperature sensor. I had a bad wiring once, the idle was like in a russian mountain. I've replaced this sensor also.
I don't know how it can be tested, i just know it seems to be a commune issue on ours 850. Friends here recommend to use Bosch OEM part.ZionXIX wrote: ↑11 Jan 2026, 09:57 I pulled the camshaft position sensor last night to inspect it. I found the tiniest bit of dry oil residue at the bottom of the housing, otherwise very clean inside. The plug was already disconnected from its mount and is basically free-floating. Im not sure how to tell if this sensor is bad. Ive watched several videos on back probing the sensor but none of them say what bad results should look like.
Yea, the more I read about normal values, the more I suspect a problem. I gave the MAF sensor a thorough cleaning but no changes on readings. I suppose if the ECU thinks the engine is getting double the amount of air, then it will reduce fuel usage to compensate this might explain the -5% long term fuel trim. Looks like I'll be digging into the parts car to see if the MAF is compatible.
A -5% LT trim isn’t crazy for a used engine. Well within trim bounds of +-20%ZionXIX wrote: ↑14 Jan 2026, 02:38Yea, the more I read about normal values, the more I suspect a problem. I gave the MAF sensor a thorough cleaning but no changes on readings. I suppose if the ECU thinks the engine is getting double the amount of air, then it will reduce fuel usage to compensate this might explain the -5% long term fuel trim. Looks like I'll be digging into the parts car to see if the MAF is compatible.