Nismo280zEd Posted June 18, 2009 Share Posted June 18, 2009 Ok, so I've been having this problem... http://www.msextra.com/viewtopic.php?f=4&t=31193&p=210763#p210763 it's been posted on here and posted on MSEFI boards. I can't seem to get MS to see the damn signal from the Sensor. Working on the car in 100+ heat and I'm about ready to destroy the board out of frustration. I've run out of things to try, any ideas are welcome. If I can send my board to somebody for inspection, that is an option too. I have no problems taking pictures of components if it would help. Let me know guys. Getting desperate, really wanted this running for Father's Day. Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted June 19, 2009 Share Posted June 19, 2009 Hi Ed, I have pin 24 = VR+, and pin 2 = VR-. I'm assuming this is a "data" and "data-not", but I've never had a scope to use on it to verify. Perhaps the inverted data is the extra pin you can't identify on your pickup? The MS drawing shows pin 2 as "where needed". I used coax on mine to suppress noise. Its 50 ohm impedance coaxial, and it is a lot thinner than cable TV coax... however I see no reason why cable tv coax wouldn't work the same. I'm just pointing out the difference since I had a comparatively easy time soldering to the ground on mine. I have data and data-not on the cores of two separate coaxial cables, snipped flush at the sensor, and the shielding soldered to battery ground at the MS side. I'm not sure what a 1k resistor is going to do for you, between data and gnd, except perhaps terminate the signal? However, its such a low frequency I'd be surprised if you needed the termination. I'd ditch the resistor. In addition to what the MS drawing shows, I also have pin #15 pulled to ground. I believe "someone told me to" do this. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted June 19, 2009 Author Share Posted June 19, 2009 I bought some shielding wire from DIY auto tune, so I have an extra 10' or so. I'll try going to PIN 2 on the MS and see what happens. -Ed Quote Link to comment Share on other sites More sharing options...
mobythevan Posted June 22, 2009 Share Posted June 22, 2009 I think you have tried enough things at this point that the only way I could help is if I had the whole setup, trigger wheel/vr sensor/megasquirt. Was there a recommendation on how close (proximity) to position the VR sensor to the 60-2 wheel? Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted July 5, 2009 Author Share Posted July 5, 2009 Yeah, I'll have to look up the spec, but I set it up with a feeler gauge to the middle of the spec range. I'm going to try running the OEM porsche VR sensor as I can't even get a signal direct from the sensor anymore. (think my oscilliscope needs to be adjusted) There is somebody on the msefi boards running the OEM VR sensor on the a crank trigger wheel, he said he had problems with "weak" signals from other VR sensor but the OEM worked fine. Worth a shot, we have two practically brand news we put in before the stock ECU took a dump. If I can't get signal with this, I'll be more than happy to box everything up and send it your way for inspection/testing. I simply don't have the space at my apart for bench top testing. Plus my wife would probably kill me with it all sprawled out in the garage for testing lol. I know it's not the easiest setup to be working with but I honestly didn't think I'd have this much trouble just getting a signal from the crank. -Ed EDIT Forgot to mention, Friday I ran some coax to try and "clean" up some signals. I removed the grounds from the motor, soldered them together, soldered the VR sensor ground to them and the other temp sensor grounds, then soldered a lighter weight coax to the ground, ran it OUTSIDE the car into the the ECU extra grounds I have for the extra coil drivers, then ran another coax from that directly to battery ground. I figured this would be an extra "clean" setup without any interference as nothing was touching the car chassis except the ground to the battery. This is when I lost signal completley from the VR sensor... but as mentioned I think my oscilliscope needs to be tuned up. I tried adjusting the VR pots again trying to get something on the RPM gauge in megatune while cranking, no luck. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted July 6, 2009 Author Share Posted July 6, 2009 Well we got the two factory VR sensors off the car and It looks promising. They have more (magnetism?) than the GM sensor on the car. So hopefully this will produce a stronger signal. Found some metal in the garage to mock up a sensor mount, should be substantial enough just to test the signal. I also noticed Porsche ran the sensor wire away from almost everything electrical, going to try a similar routing. The gentleman I was speaking with on MSextra was going to give the wiring he has them wired up with, but the forum is down. Hopefully I can figure it out with the scope. -Ed Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted July 24, 2009 Author Share Posted July 24, 2009 Good News, Rigged up a bench top setup for testing at my Father's House. Using a diyautotune 36-1 wheel and an OEM Porsche VR sensor. Signal came through clear as day on the scope on the bench setup. Very excited to test the previous Clewett sensor (GM part) Hopefully I can make it work just aswell on the bench, if so, maybe the problem lies in the AL trigger wheel on the car. -Ed Quote Link to comment Share on other sites More sharing options...
letitsnow Posted August 3, 2009 Share Posted August 3, 2009 Good News, Rigged up a bench top setup for testing at my Father's House. Using a diyautotune 36-1 wheel and an OEM Porsche VR sensor. Signal came through clear as day on the scope on the bench setup. Very excited to test the previous Clewett sensor (GM part) Hopefully I can make it work just aswell on the bench, if so, maybe the problem lies in the AL trigger wheel on the car. -Ed The trigger wheel is aluminum? I'm almost positive that it has to be a magnetic material(ie. steel or iron). Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted August 6, 2009 Author Share Posted August 6, 2009 Update, confirmed the wheel is steel, also with more bench testing I got both sensors to work very well. Using the clewett sensor, using a .020 air gap running through a 9mm coax cable getting very clean signal to the ECU. Seems the problem lied in the sensor wire mainly it was too sensitive to all the electrical noise the Porsche motor creates. Also playing with the air gap on the bench with the scope helped alot. Now I'm just trying to use the tuning pots to get MS to recognize the signal. Hopefully this doesn't take as long. Going to read over the megamanual again for some tips. Hopefully I can get this thing running before classes start again on the 25th. -Ed Quote Link to comment Share on other sites More sharing options...
ares650 Posted August 13, 2009 Share Posted August 13, 2009 I have a question for you>>>>> What did you get when you ohmed the sensor out? What did you get when you checked the AC voltage at cranking? with the good and bad sensor. I an doing a similar setup on a aircooled vw dub, and I think I am getting a weak signal. I get 680ohms and 0.04 ac volts at cranking. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted September 1, 2009 Author Share Posted September 1, 2009 Unfortunatley I was not able to do anything else with this before my classes started. Now I spend my two days off downtown from 6-5. Maybe with the new job promotion I can vet some free time to work on this again. Quote Link to comment Share on other sites More sharing options...
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