Pontiac: 1988 Bonneville still not starting
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1988 Bonneville still not starting
OK, I've replaced the coil pack, checked the fuel pressure(42 psi), unplugged the camshaft sensor and tried to start it(didn't start), and still it doesn't start up. I don't have spark to any plug. Do I have the ckp (crankshaft sensor), computer, and ignition control module left to check? I don't know how to hook up a vom to the sensor to check it. Also, the engine seems to turn over slower than normal when trying to start. Battery seems fine. Help, I need to get this running today so my kid can get to college tomorrow. Gary H. Vancouver, Wa.
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Re: 1988 Bonneville still not starting
On Sun, 11 Jan 2004 11:04:27 -0600, "GaryH"
<comcast.net> wrote:
Connect VOM to crank sensor - set to lowest AC voltage scale and
crank. You should get an AC reading. If not, the sensor is most likely
TOAST.
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Re: 1988 Bonneville still not starting
did you have the ignition module checked? Nine times out of ten when you don't have spark that is what it is.
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Re: 1988 Bonneville still not starting
GaryH wrote:
Probable bad crank sensor. I have rarely seen one last since 1988.
10-12 years seems to be about their lifespan.
As clare said, put an a/c vom on it and see if it generates a signal.
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Re: 1988 Bonneville still not starting
How do I hook up the vom??? From underneath the car and test the leads from the computer? Or do I take the sensor off of the car, connect back up to the leads and then test it? I just don't understand how to physically connect the meter? Thanks, Gary H.
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Re: 1988 Bonneville still not starting
GaryH wrote:
IIRC, the crank sensor on that year engine is the inductive type.
If so, it will generate a sine wave of 1-3v pp. If it is a Hall type
it will require a 5v reference and generate a square wave.
In either case, the output voltage should be detectable with a vom,
although a scope would be better. If it is inductive, then unplug the
plug and attach your vom there. Check for resistance... I forgot what
it should be though. Then crank engine.
If it is Hall, you will need to either make a jumper (prefered)
or tap into the wires or plug on the output side. You will be able to
determine the output side since it will not have a 5v ref.
It is rather difficult to take the sensor off the car and it is rather
touchy to put back on. Find the plug.
http://www.picotech.com/auto/waveforms/crankshaft_sensor.html
http://www.picotech.com/auto/waveforms/crankshaft_sensor_inductive_cranking.html
http://www.picotech.com/auto/waveforms/crankshaft_sensor_hall.html
http://www.wellsmfgcorp.com/
http://www.wellsmfgcorp.com/counterpoints/Counterpoint3_1.pdf
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