1989 mazada 626 stalling

I have a problem with a 1989 mazada 626 2.2L non turbo, that stalls
when the idle goes lower than 1100 rpm. I have tried changing the mass
air sensor since that checkout bad, no change. cleaned the idle air
control valve, and changed the throttle body, still no change. I have
checked for vacuum leaks and have found none. I am at a loss, it still
runs the same.

hows the fuel filtration and pressure?


"wpc" > wrote in message
ups.com...
> I have a problem with a 1989 mazada 626 2.2L non turbo, that stalls
> when the idle goes lower than 1100 rpm. I have tried changing the mass
> air sensor since that checkout bad, no change. cleaned the idle air
> control valve, and changed the throttle body, still no change. I have
> checked for vacuum leaks and have found none. I am at a loss, it still
> runs the same.
>

I would check the rubber air intake tube for any leaks - number one
possibility!

Otherwise...

Are you sure the IAC works? Or is it bolted to the throttle body and
therefore was replaced when you changed the TB?

Toyota MDT in MO

lots of fuel pressure and the filter was justed changed.

the IAC is working, though it did come with the throttle body. The
intake tube was the first thing replaced due to cracks.

wpc wrote:
> the IAC is working, though it did come with the throttle body. The
> intake tube was the first thing replaced due to cracks.


wpc wrote:
> the IAC is working, though it did come with the throttle body. The
> intake tube was the first thing replaced due to cracks.

Ok. Have you checked the idle contact switch? There's a brown wire
going to it thats 12 volts until the switch grounds it to 0 volts.

I know you said you changed the "mass airflow sensor" but since this
has a vane airflow meter, not a MAF, I wanted to make sure we're on the
same page. There is a circuit in the VAF meter that cuts off the fuel
pump relay (Mazda calls it a circuit opening relay) if the air flap
closes completely. It would be something to check out.

The solid light green wire at the VAF is what grounds when the air flap
is slightly opened. If you were to ground this wire the FP relay would
remain powered. This circuit is only a "hold-in winding" so it may not
be capable of actually MOVING the relay contacts, but if the car is
running already, then grounding that wire will keep the FP relay closed
as long as the key remains on.

If you unplug the VAF connector with key on, the Lt Green wire should
read battery voltage from the power going through the FP relay coil.
If no voltage there, suspect a bad hold-in winding in the FP relay. Of
course you will set code(s) so they will need to be cleared.

Toyota MDT in MO

wpc wrote:
> the IAC is working, though it did come with the throttle body. The
> intake tube was the first thing replaced due to cracks.

Ok. Have you checked the idle contact switch? There's a brown wire
going to it thats 12 volts until the switch grounds it to 0 volts.

I know you said you changed the "mass airflow sensor" but since this
has a vane airflow meter, not a MAF, I wanted to make sure we're on the
same page. There is a circuit in the VAF meter that cuts off the fuel
pump relay (Mazda calls it a circuit opening relay) if the air flap
closes completely. It would be something to check out.

The solid light green wire at the VAF is what grounds when the air flap
is slightly opened. If you were to ground this wire the FP relay would
remain powered. This circuit is only a "hold-in winding" so it may not
be capable of actually MOVING the relay contacts, but if the car is
running already, then grounding that wire will keep the FP relay closed
as long as the key remains on.

If you unplug the VAF connector with key on, the Lt Green wire should
read battery voltage from the power going through the FP relay coil.
If no voltage there, suspect a bad hold-in winding in the FP relay. Of
course you will set code(s) so they will need to be cleared.

Toyota MDT in MO