Spark, Fuel, NO FIRE!!!
09-25-2004, 06:41 AM
#91
Burning Brakes
Join Date: Apr 2002
Location: Long Island, NY
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the following is a cut and paste from a thread i made a few days ago on a free easy way to check sensor waveform behavior. s and s2 cars only have one sensor so we get speed and reference in one signal. you would need to record two separate sound waves to see speed/reference. next time your car's not starting, make a recording. if it looks fine than it must be an electrical connection somewhere up the line or a different problem entirely:
for all of you who aren't sure if your speed/reference sensors are functioning correctly, i've thought up a way to do it. this will work for pretty much any variable sensor but the one that quickly comes to mind on our car is the speed/ref.
got an old pair of headphones that i didn't need and cut the 1/8" jack off with some cable left on it. hooked the wires up to my reference sensor's pins and the plug into my microphone jack on my computer. yes that's right folks, a computer's sound card is an analog/digital convertor. all you have to do is use some sound recording software and hit record while cranking the car. sure would be nice if i could figure out a way to convert db to voltage so i could see if the peaks are in fact +-3v. here you can see the output in sound forge zoomed in a bunch:
got an old pair of headphones that i didn't need and cut the 1/8" jack off with some cable left on it. hooked the wires up to my reference sensor's pins and the plug into my microphone jack on my computer. yes that's right folks, a computer's sound card is an analog/digital convertor. all you have to do is use some sound recording software and hit record while cranking the car. sure would be nice if i could figure out a way to convert db to voltage so i could see if the peaks are in fact +-3v. here you can see the output in sound forge zoomed in a bunch:
09-27-2004, 09:38 PM
#92
Burning Brakes
Andrew, this can be a big help...we just need to be reminded that this is from your 16v car and Aaron's 8v car waveforms will not look exactly the same...but it would tell him whether the sensor(s) are transmitting or not
09-27-2004, 10:27 PM
#93
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Robby have you tried thumping the passenger side floor board hard when it wont start? Maybe you have bad solder connections on the DME computer.
