Air flow meter problem?!

Wed Jul 12, 2006 4:09 pm

Hi guys,
Has anybody had an airflow meter go wrong? If so what are the symptoms.
I think i may have a problem with mine.

Wed Jul 12, 2006 5:00 pm

if there's bad idle, it is not the AFM.

bad afm symptoms:

stuttering under light load , typically worse @ 2.2-3K rpms, accompanied with a massive flat spot in the same rpm range, car will feel wheezy and breathless.

TBH dude, post up the symptoms you have, and this may be a lot easier to answer

Wed Jul 12, 2006 5:06 pm

It runs like a bag of crap for the first 30 seconds when you start it in the morning (bad idle, misfire type symptons when you rev it) and by the time you've got off the drive its fine....until the next morning

Its a 1990 316i i'm pulling my hair out trying to work out what it is!
I've put a new throttle switch on it and taken the idle air control valve off and put power to it and that seems to work fine...any ideas?

Wed Jul 12, 2006 5:11 pm

My mates theory was the AFM was full of crap and when you left it sat the crap settled on the switch, but was brushed to the side once the car ran?!

Can you take the AFM apart without wrecking it?

Thu Jul 13, 2006 2:39 am

just a guess but it sounds like the thermal time switch maybe someone can back me up

Thu Jul 13, 2006 9:09 am

thermal time switch? Which ones that?

Thu Jul 13, 2006 9:21 am

Ratfink wrote:thermal time switch? Which ones that?

Doesn't exist on anything made in 1990, so don't worry about that one.
Sounds more like it fouls a plug or two, or runs extremely rich at first start up. Leaking injector? oil or water into cylinder? Plugs/ dis. cap/ rotor?
Clean out the plug recesses and take all the plugs out. Turn it over on the starter from cold, and see if it blasts anything out of a plug hole.

Thu Jul 13, 2006 10:18 am

sounds like a plan i'll give it a go thanks

Thu Jul 13, 2006 10:33 am

Brianmoooore wrote:
Ratfink wrote:thermal time switch? Which ones that?
Doesn't exist on anything made in 1990, so don't worry about that one.
Sounds more like it fouls a plug or two, or runs extremely rich at first start up. Leaking injector? oil or water into cylinder? Plugs/ dis. cap/ rotor?
Clean out the plug recesses and take all the plugs out. Turn it over on the starter from cold, and see if it blasts anything out of a plug hole.

I think he means the blue temperature sensor

Iain T

Thu Jul 13, 2006 11:04 am

Templ8e30 wrote:
Brianmoooore wrote:
Ratfink wrote:thermal time switch? Which ones that?
Doesn't exist on anything made in 1990, so don't worry about that one.
Sounds more like it fouls a plug or two, or runs extremely rich at first start up. Leaking injector? oil or water into cylinder? Plugs/ dis. cap/ rotor?
Clean out the plug recesses and take all the plugs out. Turn it over on the starter from cold, and see if it blasts anything out of a plug hole.
I think he means the blue temperature sensor

Iain T

I've changed that...made no difference

Thu Jul 13, 2006 11:37 am

Templ8e30 wrote:
Brianmoooore wrote:
Ratfink wrote:thermal time switch? Which ones that?
Doesn't exist on anything made in 1990, so don't worry about that one.
Sounds more like it fouls a plug or two, or runs extremely rich at first start up. Leaking injector? oil or water into cylinder? Plugs/ dis. cap/ rotor?
Clean out the plug recesses and take all the plugs out. Turn it over on the starter from cold, and see if it blasts anything out of a plug hole.
I think he means the blue temperature sensor

Iain T

LE jet stuff used a separate thermotime switch