Attempted first start-no rpm signal

[SpeedFrK]

Hey guys,

So I finally finished my install and am having issues with getting an RPM signal. So I am running MS3 Base with MS3 1.4.0 firmware. I am running a VR sensor from a 4.0L Ford motor(Explorer) and have verified that I am getting a strong AC Voltage signal across pins 1(Ground) and 24(Signal in) so I think the hardware is ok. I followed the MS3Base hardware manual to a tee. I have TACHSELECT to VRIN, IGN to IGBTOUT, and TSEL to VROUTINV. I am running a 60/2 wheel with a .020" gap between the sensor and the wheel. As for ignition I am using my stock distributor and single coil which I have the negative terminal wired up to pin 36. Naturally Q16 is installed, R57 is removed and I have IGBTIN jumpered to JS10(IGN), I had it on the top of R26 but that didnt yield anything either. I also tried having TSEL to VROUT as well and that did nothing either. I have turned R52 and R56 until the cows come home. I tried 12 turn CCW, then 18, then 25, now I dont know where they are but its alot. I never heard a click or feel any difference in the the way the screw spins so I have no clue where the end of the turning is....

Based on my tune and the limited information I can find on how to configure my Ignition setup and I think I have it right, but you all will be the judge. Attached is my tune and some photos of the board for your reference. Thanks alot for the help.

[DaveEFI]

Since you have the means to check the presence of the VR signal, check also at Tsel, which is the output of the VR conditioning circuit. It should be a 5v approx square wave.
Put both pots back to the default fully anti-clock position. If nothing at Tsel, turn R56 clockwise a turn at a time. I find 6-8 turns usually works if no signal at the default.
R52 doesn't normally need adjusting here.

[SpeedFrK]

Ok so new day and I have done a few things but still no progress.

DaveEFI,
I am only working with a multimeter for checking the VR Signal so no oscilloscope to verify a square wave. I used the instructions at this link, http://www.diyautotune.com/tech_article ... s_test.htm in order to verify the VR circuit is hooked up correctly and from what I can tell everything seems fine except for U7 pin 1 reads a high value when I supply a ground signal to pin 24 instead of the 5V signal, see last step on the link i provided. I used those instructions to set the Pot position for R56 such that the reading on Pin 3 of U7 was at exactly 1.5Volts with no power applied to pin 24. Pin 2 reads 5V when 5V is input to DB37 pin24 and Pin 3 goes down to 1.282V. Pin 2 reads 0.962V when a ground signal is applied to DB37 pin 24 and pin 3 goes up to 1.72V. As I understand it, and according to those instructions, I should be seeing a 5V signal on U7 Pin 1 when 5V is applied to DB37 pin 24 but I see 0.1V (The Low signal) and when I ground DB37 Pin24 I see 4.28 V (The high signal) and therefore its backwards. Currently the TSEL is wired to VROUT. I tried to wire it to VROUTINV but the behavior on U7 pins 1,2,3 are the exact same. Could it be possible U7 is bad or that I installed something backwards that would cause this comparison signal to be backwards?

At the end of modifications I have verified several things emphatically:

1.The voltage signal from the VR is coming into pin 24(Signal) and pin 2(Ground), I traced back from the sensor pin on the bottom of the engine to the DB37 Pins and everything looks good. I also can see the voltage jumping around on my meter when I turn the motor over.
2. Based on my checks of the VR circuit everything seems to be working just right except for what I explained above.
3. The gap on my sensor is pre-set by the plastic mounting bracket built into the Ford sensor I am using.
4. My TS settings, see tune, are set correctly.
5. I get no RPM signal of any kind.

I have also been playing with my IGBTIN jumper. Originally I had it wired to the JS10 and when I attached that tune I had my spark output set to JS10. I have now attached that jumper to the top of R26 and have set my spark output to LED's. This is something I have found tons of conflicting information on, I could use some guidance on what this should be.

Anything else I should try? I am at the end of every piece of documentation I can find and am out of ideas. Please help

[billr]

I gotta ask... are you sure your cable connecting to the "DB37" has correct pin-outs? It looks like you aren't using a standard DB37 there. Post a run log while cranking.

[SpeedFrK]

Its reasonable to ask that. I have traced back the VR signal In and ground for the sensor to the soldered connection for my "custom" DB37 and they traceback all the way to where the sensor connector is. I have put a meter on the pin 24 and pin 2(VR Ground) and see the AC voltage moving around as the motor is cranking. Attached is my spreadsheet I used to connect each DB37 pin to the factory Bosch 35 Pin connector. Everything else is working as it should IAT,CLT, TPS, MAP etc. Just rechecked all connections in the PDF once more.

I have attached a log during cranking. This is my first time asking a technical question on this forum and my first megasquirt install so if I messed this up please be gentle.

Anyone in upstate SC have an oscilloscope they would be willing to lend me for a day?

I was really hoping that I messed something up in my tune that would cause the signal to not be showing up in the logs or in TS dash. Has anyone taken a look at the tune to see if I mucked it up? Thanks again.

[billr]

I did look at the MSQ briefly, nothing jumped out at me as to why no rpm detected. Post a tooth log.

[SpeedFrK]

I recorded a trigger log earlier and opened it in excel and it was empty, see attached. Which I thought was odd and is why i did not post it with the log file. I just tested the trigger logger with my stim and its working just fine. That would mean there is no trigger signal correct?

[DaveEFI]

Have you checked U7 between pin 8 (5v) and pin 4 (ground) to make sure there is 5v under all conditions?

Examine U7 carefully with a magnifying glass and make sure the solder to each pin has flowed to both sides of the board.

You should see a reading of sorts at Tsel with your DVM set to AC. I'll try and check later what this would be.

[billr]

"I just tested the trigger logger with my stim and its working just fine."

I'm hoping that means the mainboard is fine. Try to get a tooth-log, both with the Stim and then with actual cranking.

[SpeedFrK]

Its been pretty cold here lately and I dont have a garage so no much has been done. I went through all of the connections and tested the U7 pins, all seem good to go. Tried both the trigger logger and the tooth logger and neither is creating logs with any data in them. When I use the tool on the stim I get beautiful trigger pulses but when in the car...nothing. I was looking at my custom fabbed bracket for the VR sensor and it looks like its centered and perpendicular with a .020" gap but it may not be. I just bought a Hall effect sensor from DIYautotune because I cannot verify whether the sensor is good or not so this should eliminate any issue with that. Once I use a brand new sensor, plus I am hoping the Hall effect will be less temperamental compared to the VR sensor.

[DaveEFI]

A VR sensor shouldn't be temperamental. Indeed, they are general more reliable than a hall effect, as they are a more simple device. If yours is temperamental, something somewhere is wrong. May millions are in use without problems.

That you get a decent tach signal with a Stim suggests MS is probably OK. But the Stim VR simulation isn't exactly the same as the waveform from a real VR sensor, so MS may well need adjustment between them.

The one part which is the same with either the Stim or a VR sensor should be the output from the VR conditioning circuit to the processor. That's what that circuit does - takes any suitable input and conditions it into a uniform output suitable to be read by the processor.

Now a scope is the best way to look at a waveform, but your DVM set to AC shroud give a reading at the output of the VR circuit (Tsel) if you don't have scope. What it would read depends on the design of the DVM. But if you get a tach signal with the Stim, see what it reads and note it. You should get the same reading with the VR sensor at Tsel.
What would vary is the DVM reading you get at the input of the VR conditioner (TachSel) between the Stim and a sensor.

[SpeedFrK]

So i solved it, sorry for the delayed post. It was several issues. The first being the gap was just a bit too large between the VR and the Wheel. I used a Ford Explorer 4.0 sensor that had a gap setter molded into the mount for the sensor, so i assumed that was the gap I needed. I measured it at 0.020. I ground off that part of the mount with a dremel and now the sensor is sitting a hair width from the wheel. I am getting a strong RPM signal now. I did have to fiddle with the POTS a bit to get the RPM signal and cranking signal to stay on...they would blip in and out initially. I found that R52 needed adjustment. Thanks to you guys for you help, but it ended up being something silly as it normally would be.

On to the next issue...no spark using a single coil driver. I have pretty much given up on that one because I think the coil is bad.... I plugged a spark plug directly into the coil and used the test mode. I could hear the spark plug ticking but no spark...I am assuming the coil is dead. I am currently in the process of installing CNP setup using the FET driver method in the MS3 Manual but am having issues. If you see this and can help with my ignition issue please pop over to my other post and lend a hand....really appreciate you guys. This stuff can be frustrating most of the time, but this forum offers some solace.

http://www.msextra.com/forums/viewtopic ... 31&t=61462