86/1 944: Reference Sensor Question
04-24-2018 | 04:48 PM
#1
Thread Starter
Track Day
Joined: Apr 2018
Posts: 17
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86/1 944: Reference Sensor Question
I had a reference sensor reading that I don't understand. On terminals 8-27 of my reference sensor and on terminals 25-26 of my speed sensor, I got a resistance of about 900, which is in adequate range. On terminals 8-23 of my reference sensor and 25-78 of my speed sensor, I got no reading at all. I tested the terminals with the car off and with the ignition set to on, same reading. Not sure what the problem is here, any help would be appreciated.
04-25-2018 | 03:44 PM
#2
Rennlist Member
Joined: Oct 2002
Posts: 12,008
Likes: 97
From: Hyde Park, NY
You mean you're checking at the DME plug?
These sensors are hall effect sensors. When the flywheel is spinning around, they'll make a small induced voltage. You can see this as blips on an oscilloscope. It's not something you can really check with a multimeter.
04-27-2018 | 10:48 AM
#3
Thread Starter
Track Day
Joined: Apr 2018
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Per Clark's, I was checking from the actual reference sensors with a multimeter:
http://www.clarks-garage.com/shop-manual/ign-02.htm
http://www.clarks-garage.com/shop-manual/ign-02.htm
04-27-2018 | 10:55 PM
#5
Drifting
Joined: Aug 2017
Posts: 3,149
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From: Toronto, Ontario, Canada
PS the pins you are trying to measure could show mysteriously on your multimeter as they are supposed to be extremely high reading.. > 1 Mega-ohm. You may not have the VOM set correctly. In any case, this is likely not the test you need to confirm
04-28-2018 | 08:08 AM
#7
Drifting
Joined: Aug 2017
Posts: 3,149
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From: Toronto, Ontario, Canada
Are you just having fun measuring stuff around the car or do you have an issue like, say, a no-start condition?
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04-28-2018 | 11:20 AM
#9
Drifting
Joined: Aug 2017
Posts: 3,149
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From: Toronto, Ontario, Canada
If you haven’t pulled your ref sensors out or changed them, I would start instead with the basics.
Look up online how to test the DME relay. If it passes....
PULL OUT FUSE NUMBER 34.
1. Get yourself a 12v LED. An electronics parts supply should have one. Very, very cheap. If it doesn’t have wires on it, you will have to solder or connect a pair. Ask them to help. Also, ask them to show you which side is negative. Also pick up a few aligator clamps.
2. Hook up the little LED wires to the ignition coil, putting the negative on the screw with the green wire and the other end on the other screw. Use the aligator clamps.
3. Crank the engine. If LED flashes, your ignition system is working. If no LED light, you may have issue with DME or ref sensors. If it lights, pull any spark plug out and rest it (with wire attached) on the intake manifold. Crank the car to see if it sparks. If yes, go on to step 4. If not, change your spark plugs and possibly distributer cap + rotor & wires. You can test these first.
4. Pull any of the fuel injector wires. To do that, take the leads of a multimeter (or similar thin strong metal) and from the top, pop both ends of the spring clip off the top so the ends rest on the side. Then, pull the plug out. Pop the spring clip ends back on top so you can push the plug back after.
5. Attach your LED to the plug end. Doesn’t matter which way. Crank the car. If LED flashes (dimly), then fuel system should be working. Check your fuel pump. If no light, you could have issue with DME or ref sensors.
Scroll through my youtube channel’s recent videos and you’ll see what the flashing LED looks like in action http://youtube.com/danielmartinic
Look up online how to test the DME relay. If it passes....
PULL OUT FUSE NUMBER 34.
1. Get yourself a 12v LED. An electronics parts supply should have one. Very, very cheap. If it doesn’t have wires on it, you will have to solder or connect a pair. Ask them to help. Also, ask them to show you which side is negative. Also pick up a few aligator clamps.
2. Hook up the little LED wires to the ignition coil, putting the negative on the screw with the green wire and the other end on the other screw. Use the aligator clamps.
3. Crank the engine. If LED flashes, your ignition system is working. If no LED light, you may have issue with DME or ref sensors. If it lights, pull any spark plug out and rest it (with wire attached) on the intake manifold. Crank the car to see if it sparks. If yes, go on to step 4. If not, change your spark plugs and possibly distributer cap + rotor & wires. You can test these first.
4. Pull any of the fuel injector wires. To do that, take the leads of a multimeter (or similar thin strong metal) and from the top, pop both ends of the spring clip off the top so the ends rest on the side. Then, pull the plug out. Pop the spring clip ends back on top so you can push the plug back after.
5. Attach your LED to the plug end. Doesn’t matter which way. Crank the car. If LED flashes (dimly), then fuel system should be working. Check your fuel pump. If no light, you could have issue with DME or ref sensors.
Scroll through my youtube channel’s recent videos and you’ll see what the flashing LED looks like in action http://youtube.com/danielmartinic