no VR crank signal / sequential / R32 VW

[mattgreeneva]

I have wired up the the stock sensor what I think to be the correct way and also any combination of other ways and I still do not get rpm's when cranking.

1= Shield
2= Black (-)
3= Yellow (+) (gets signal on my multimeter when cranking)

Connected the yellow to VR+ and the black to VR- and grounded the shield.

I also tried it flipped around and 5 other possible ways. I am thinking something else is wrong somewhere or maybe its a stupid trick I don't know.
Megatune has a good tune on it from a running 3.2 24v plus it was written by Paul so I am thinking that's not the problem at all.

On sequential does RPM signal depend on both crank and the cam sensor?

Sorry if these are stupid questions this is my first time. Everything else is done and reads good and I thought today was the day to start the car but after priming the motor and oil cooler with the starter I realized I was not getting an RPM reading.

Thanks

[billr]

Is this a VR sensor? I'm thinking it is, with just two wires and a shield. I'm struggling to figure out how you could connect it "5 other possible ways". If it is a missing-tooth wheel you will get an rpm reading regardless of what the cam sensor is doing. Post both tooth and composite logs, as well as...

[mattgreeneva]

Is this a VR sensor? I'm thinking it is, with just two wires and a shield. I'm struggling to figure out how you could connect it "5 other possible ways". If it is a missing-tooth wheel you will get an rpm reading regardless of what the cam sensor is doing. Post both tooth and composite logs, as well as...

It is a VR sensor with just 2 wires and a shield. I tried connecting it as described above. Then reversed. Then grounding the black then grounding both blacks then grounding all wires and seeing if just the shield would pick up anything the list goes on.

Let me learn how to do that and I will post them for you. Like I said I am still new and learning but thank you for the response.

[billr]

Until you learn how to post logs and tune... do you get an AC voltage across the VR +/- leads while cranking? Is it the same, whether connected or disconnected from the harness? (What is the voltage?) What is the resistance between those leads, and are both "open circuit" relative to the shield?

[mattgreeneva]

Until you learn how to post logs and tune... do you get an AC voltage across the VR +/- leads while cranking? Is it the same, whether connected or disconnected from the harness? (What is the voltage?) What is the resistance between those leads, and are both "open circuit" relative to the shield?

I cant figure out how to post it unless you just want a screen shot of it. I cant even open the saved log on my computer... But I can tell you how it looks... Big black screen. Nothing going on. Except for the sensors on the left side that do work... RPM counter still stays at 0

I messed around with the tuner studio when I got up this morning but I am working now and will get the voltage and stuff for you this afternoon when I get off

[grom_e30]

http://www.msextra.com/doc/general/forum_posting.html

[mattgreeneva]

I have uploaded the MSQ and the data log wouldn't do anything. All that it logged was the windows. The only one that changes while cranking is the pressure. Everything else stays constant. I uploaded what MS gave me but after looking at it its just blank tabs.

as far as the measurements.
do you get an AC voltage across the VR +/- leads while cranking? Yes .6AC while cranking
Is it the same, whether connected or disconnected from the harness? No it drops to .4AC. If it matters I am getting 2.8AC from the MS wires while cranking
What is the resistance between those leads, and are both "open circuit" relative to the shield? Resistance is .75 and I dont know what you are talking about for the last part. I just learned what a shield was yesterday when I started wiring the crank.

Thanks again for the help

[mattgreeneva]

MSQ is attached here. Didn't upload last time for some reason

[DaveEFI]

Which range on the DVM were you using to measure the VR sensor?

0.75 ohms would be faulty to me - near enough a short. 750 ohms, on the other hand, about right.

[mattgreeneva]

Which range on the DVM were you using to measure the VR sensor?

0.75 ohms would be faulty to me - near enough a short. 750 ohms, on the other hand, about right.

Like I said, I am new to all of this... Just went and tried a different setting and got 759. I don't know which setting to use on my multimeter.. has a lot of them. I just picked one under the Ohms section

[grom_e30]

That sounds about correct for a bosch sensor, on my bmw i found on the vr sensors that the black wired was vr+ and the yellow was vr-

what ecu is this any how v3 or v3.57??

[mattgreeneva]

v3

[grom_e30]

any chance you can get composite and tooth logs so we can see whats going on with the crank signal.

http://www.msextra.com/doc/pdf/html/Meg ... p-1.3.html

page 45&46

[billr]

"No it drops to .4AC. If it matters I am getting 2.8AC from the MS wires while cranking"

That has me confused. If it is .4 VAC with sensor connected, then does that "2.8AC" mean 2.8 volts AC, at the harness wires, and with sensor disconnected? That doesn't seem right, I wouldn't expect that much voltage to come back on the harness from the MS if the sensor is disconnected. Yes, I understand you are new to an electrical multimeter, we will be patient as you learn. It will be a valuable skill in many ways, not just for this MS project!

[mattgreeneva]

any chance you can get composite and tooth logs so we can see whats going on with the crank signal.

http://www.msextra.com/doc/pdf/html/Meg ... p-1.3.html

page 45&46

When I run the tooth log nothing shows up at all. The ecu is not seeing the sensor. It is just a blank screen. Which is why it wont data log anything. Nothing is happening

"No it drops to .4AC. If it matters I am getting 2.8AC from the MS wires while cranking"

That has me confused. If it is .4 VAC with sensor connected, then does that "2.8AC" mean 2.8 volts AC, at the harness wires, and with sensor disconnected? That doesn't seem right, I wouldn't expect that much voltage to come back on the harness from the MS if the sensor is disconnected. Yes, I understand you are new to an electrical multimeter, we will be patient as you learn. It will be a valuable skill in many ways, not just for this MS project!

It is .4 volts AC connected and when I disconnect it all and just crank the car and measure the wires coming from the MS box I get 2.8 volts AC from the wires coming from the box not connected to the car. That is something I also didn't understand is why the wires coming from the MS box are showing + voltage when it is supposed to be reading voltage coming from the sensor. That is the reason I mentioned it.

I would think the crank sensors coming from the box are supposed to be reading not pushing out power.

[grom_e30]

the vr circuit outputs its own voltage that gets pulled down by the sensor, if you measure between the vr wires with the sensor disconnected should get a dc voltage when the ecu is on.

[billr]

True, that tach input circuit has a DC bias, but if the OP is really seeing a 2.8V AC voltage when cranking (and I assume it is 0 AC when not cranking...), then I think that is a big clue. We need the OP to confirm there is 2.8 VAC, at the harness (MS input) and with the sensor disconnected. Also would be good to confirm it is near-zero VAC when not cranking.

[mattgreeneva]

It seems to be different every time I do it. I just ran it with a fresh battery
VR+/- wires coming from the MS box
Ignition off: .16 DC volts and 0 AC
Ignition on: 3.06 DC and 5.3 AC
Cranking: .10 DC and 0 AC

[billr]

Confirm: those last readings are all volts, none are milli-volts?

[mattgreeneva]

This is the meter I have. Measurements were done for DCV at the 20 setting and ACV at the 200 setting