problems stating my car

[Bernard Littau]

Could be a bad Hall Sensor, either on the flywheel or the distributor.  They
tend to have this behavior of working at normal operating temperature, or
cold, but not when hotter.  The sensors heat soak when they sit for 10
minutes -- they get hotter than normal operating temperature.

One way to test this is to get a can of freeze spray -- they use these in
electronics repair -- and when the car is not starting, blast one or both
sensors and see the effect.  If they work again when they are cooled down,
they are likely at the end of their service life.  As they age the Hall
Sensor's waveform gets worse and worse.  It also gets worse when they get
hotter.  Eventually they get to the point where the waveform is bad enough
the ECU can't sync to the signal.  This typically happens first in the heat
soak phase 10 or so minutes after you stop the car.

Even a can of "air" used to clean computers might work; you can get those at
just about any computer store.  I think Costco sells them by the case.  You
only need to cool the sensor down a bit, not freeze it.

Best,

Bernard
Woodinville, WA
'88 5ktq


On Sat, Feb 23, 2008 at 1:13 AM, Leon <proleonk at gmail.com> wrote:

> Sounds like it has an issue when the engine is hot - aka hot soak. Did
> you already check all your ground cables, distributor cap, rotor,
> wires, plugs, air, fuel filter and such? Verify those are all in good
> working condition and replace as necessary. Have a look when cranking
> (assuming it cranks freely but doesn't catch). See if you got spark
> and or fuel issues. My bet its not getting fuel, it is caused by a
> faulty check valve on the fuel pump. Do some research at the
> audifans.com data base/archives. If you need one, feel free to ask,
> otherwise they are like $12 at autohausaz.com.
>
> Dave
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