There are four terminals on the AFS. For the sake of this article I am numbering them 1,2,3 and 4. Terminal 1 is the outboard terminal, nearest the fender, 4 is inboard nearest the engine. This is really bad, as it will quickly destroy the O2 sensor, and the hose itself will eventually fail. I am a silicone hose dealer and manufacture, so take this seriously. The system does NOT run all the time. It uses an air pump with a magnetic clutch. With Motronic Basic we will have to remove a connector from a fuel injector. It’s easiest to remove it from the forward most injector.
The second thing that kills O2 sensor is a problem. It’s silicone. If exposed to oil, silicone gasket cement or engine sealers will break down and get into the engine’s oil. With the throttle closed you should see continuity (meaning essentially zero ohms of resistance) between terminals 2 and 18. If it doesn’t pass this test, it could mean that the switch is bad. Some of that oil will be burned and make its way to the O2 sensor where the silicone will, over time shorten it’s life. Мотор S38 B36, по сути представляющий собой форсированный вариант М30 с двадцатичетырехклапанной головкой блока и системой VANOS (фазовращателями на впускном валу), а также спортивным многодроссельным впуском, ставился на М-версию машины.
Note: fuel pressure does NOT vary with RPM, it varies with manifold pressure/vacuum. It’s possible to have the engine at 2000rpm with very little throttle, in which case it would have quite a bit of vacuum and relatively low fuel pressure. When not at full throttle, the flap is open and the plenum is not divided. Once again you will need to get out your OHM meter. We do this test first because if the injector fails this test, it’s junk and can not be fixed.