325 stupid air mass fault

Mon Aug 17, 2015 4:59 pm

Hi all a few weeks ago driving my e30 into work to get worked on it cut out long story short loose battery terminal was the cause. Ever since I get a rough idle bogging revs until warm and petrol fumes that melt my eyeballs. I scanned it and it comes up with 7 airflow sensor circuit. If I clear it it comes back instantly. I've changed coolant temp sensor. Crank sensor. Fuel pump. Tried another afm off another car and it's still the same any help appreciated in advance.

Mon Aug 17, 2015 6:39 pm

Check the resistance readings of the blue coolant temp. sensor AT THE ECU PLUG, hot and cold, as you should have done before replacing anything.
Test, not replace. Random parts changing causes more problems than it solves.

Sat Aug 22, 2015 5:17 pm

Could be a coincidental vacuum leak. If you haven't replaced ALL the vacuum hoses on a car of this vintage, you should.
I replaced nearly all, missed one and chased symptoms like yours for a long time before a shop guy found it.
The advice about testing not replacing is now tattooed on my forehead