no rpm signal

[mutly]

Finally getting start my motor after a long build. I have a porsche 2.0L motor with MS2 V3 set up for EDIS and relay board. Megatune shows that I'm getting all the proper gauge reading with the exception of the RPM. It shows no RPM at all, so I know i will get no spark or fuel. I'm thinking maybe the VR sensor is wired backwards. Looking to the experts for some help with this.

[DonTZ125]

Are you using a 36-1 wheel?

[mutly]

Yes it's a 36-1 wheel. all the EDIS components are from boost engineering. I checked the gap between the wheel and the VR sensor. It could stand to be a little less of a gap, but it's at .045.

[trakkies]

Is there a spark when cranking? EDIS should work even when no connection is made to MS.

[mutly]

Not sure about the spark at this point. I discovered the RPM signal problem as I was checking my Tuner Studio settings after getting a new computer. I've been trying to attack problems as they come up, so I don't lose track of where I am in the process. At this point I figured that if I get the RPM problem fixed now it will eliminate others later.

[trakkies]

Not sure about the spark at this point. I discovered the RPM signal problem as I was checking my Tuner Studio settings after getting a new computer. I've been trying to attack problems as they come up, so I don't lose track of where I am in the process. At this point I figured that if I get the RPM problem fixed now it will eliminate others later.

The no tach signal to MS could be caused by a connection problem, EDIS not working, how you've set the MS software for tach input, and probably more I've forgotten. Since EDIS will work standalone, I'd eliminate that first.

[Wildrider49]

Hey Mutly, I'm in the same stage as you on the same engine as well. I am using a Ford 32-1 tooth wheel on a 2056cc Type 4. I am using low impedance Bosch 912E injectors with ballast resistors, no EGO, and a Bosch air bypass that heats up on it's own. I would love to share tuning and troubleshooting hints with you as we both work to get these cars started ;) What do you say?

--Tony

[mutly]

No problems here. It would be great to share information. I don't know if I would be moving fast enough to really help though. Between work and coaching my days are full. Usually I do my builds and troubleshooting on my off days when they happen. It's been a slow process so far. With that being said, this is where I am right now. Went back to check my megasquirt build for any errors. After putting the Stim on the ECU I found that all my inputs are good. The only questionable thing I found was that the RPM only showed a quick upswing and the green synch light came on momentarily. This from what I found is normal according to the megamanual because it doesn't read RPM very well with the VR sensor circuit. If I turn the knob on the stim quickly I get a quick upswing in RPM, but nothing steady. I've reset the gap between the VR sensor and the wheel. Hopefully that will help. My next move is to hook-up the Multi-meter to the connector at the EDIS controller and motor the engine and see if I get a positive reading confirming if I have the VR sensor wired backwards, or not. I hoping that it will be that simple. I have to wait until I replace the car battery before I can go any further. My old one died and won't take a charge. I will keep you updated as thing progress.

[trakkies]

I used the opto input for EDIS as per the MS instructions. Worked perfectly from the start - and also works with the Stim. Why did you use the VR input?

[mutly]

Sorry about that last post. Trying to do to many things all at the same time. I did indeed use the opto circuit during the build. I however never got a very strong RPM signal useing the stim. The reading was always hit or miss. I'm hopeing at this stage that it's just the VR sensor or wiring. It would be much easier to correct than to take apart the ECU and correct the jumpers. I was going to set the trim pots to the full counter clockwise positions and check the readings again with the stim and see if that helps. I'm sure it will be something simple that I just overlooked.

[roachdogg28]

Hey mutly, i had a very similar issue when i switched over to direct coil control. I finally ended up building a soundcard oscilloscope with my laptop, and i traced the vr circuit to find i missed some flux buildup on some important components, recleaned and now it works great...ignition atleast

What i built is not a true oscilloscope obviously, but a way to hear/see the rpm signal from the vr sensor. It might be an option for you if you don't get it figured out. If you decide to try this here's the circuit plus some others- http://www.megamanual.com/ms2/pcb.htm

Im also correcting some problems with my type 4 2.0 but im running ms1 in my beetle. Good Luck!!

[mutly]

I'm not sure if I've made things more complicated or not. I went back into the ECU (MSII V3) to double check my assembly. This is what I have. I'm looking for some feedback as to whether or not this is correct. This mod is for EDIS with full fuel control. I'm still not getting any RPM signal to the MS. I have the following jumpered:
D1 and D2
OPTOIN to TACHSELECT
TSEL to OPTOOUT
JS10 to IGN
XG1 to XG2

Does this look correct. Any help would be greatly appreciated. I'm an RPM signal away from getting the engine started for the first time.

[trakkies]

Is C30 present? I dunno how much effect this has - the instructions say not to fit it initially when using the opto input, so I didn't.

[mutly]

It is not present, but it is jumpered as per build instructions. I started my troubleshooting. I started at the VR sensor. The gap is set correctly. I disconnected the connector at the EDIS module. hooked-up a multi-meter to pins 5 and 6, and rotated the motor. I got a strong AC voltage signal at the connector. Whether the wires from the sensor are reveresed is still to be found out. I get a strong signal whether I have the + lead on pins 5 or 6. If the ECU build looks correct my next step is to reverse the VR sensor wires at the EDIS unit and try again. If that does not work I'm going to reverse the wires at the relay. I'm thinking maybe I have the wrong wire coming from the EDIS unit to the TACH input at the relay. I doubt it, but at this point I don't want to leave any stone unturned. If that does not work it's time to dive into re-wiring everything.

[trakkies]

It is not present, but it is jumpered as per build instructions. I started my troubleshooting. I started at the VR sensor. The gap is set correctly. I disconnected the connector at the EDIS module. hooked-up a multi-meter to pins 5 and 6, and rotated the motor. I got a strong AC voltage signal at the connector. Whether the wires from the sensor are reveresed is still to be found out. I get a strong signal whether I have the + lead on pins 5 or 6. If the ECU build looks correct my next step is to reverse the VR sensor wires at the EDIS unit and try again. If that does not work I'm going to reverse the wires at the relay. I'm thinking maybe I have the wrong wire coming from the EDIS unit to the TACH input at the relay. I doubt it, but at this point I don't want to leave any stone unturned. If that does not work it's time to dive into re-wiring everything.

If C30 is jumpered, your problem is solved. Remove the jumper. It is shorting out the signal.

[mutly]

I gave you wrong information. It was thinking of the R43 I have jumpered. I have the top hole of C30 (the one towards the heat sych) that is jumpered to S12C. Here is the complete list of jumpers I have installed.
R38
R37
R43
D1
D2
ING to JS10
Upper hole of C30 to S12C
OPTOOUT to TSEL
XG1 to XG2
TACHSELECT to OPTOIN

Sorry about that last message. My head was somewhere else.