Trying to get my brother in laws turbo 2 running. We didn't get it going I believe due to no CAS signal. I wasn't sure it wasn't the wiring so today I pulled an extra CAS and wired the megasquirt 1 V3 up to power and the CAS to see if I could find a signal. Well I see that the ignition advance changes when I rotate the CAS. I am trying to run a v3 with Error's board. I have counter clockwise rotated all the pots as far as I could tell the end of their movement. Not sure what the problem is so I have attached the MSQ and two data logs. Test 1 is actually G+/- and test 2 is Ne+/-. Please take a look and see if you see anything wrong. The unit was pre-built by Glenn's garage so the unit should be good unless I setup something wrong.
Any suggestions would also be great. Thanks...

 

usually when advance changes without anything else changing you either have no signal on G, or Ne while getting a signal from the other, or you have Ne and G wired to the wrong conditioners.

Ne should be wired to the built-in v3 conditioner, G to the lm1815, and the lm1815 to pin 11 on the CPU.

Ken

 

I have it wired for Ne on V3 board and G on the error board. I thought I would try G on V3 board just in case. I also just checked the board it and its on pin 11. I was not sure what to look for in the logs in terms of signal. I know the leds are not flashing. Anything else I should check. It looks like I wired Ne+ and - are wired correctly. Should the pots be adjusted to anything but completely counter clockwise? Also does it matter that I'm testing with only one, Ne or G connected only, could I set the msq up so that I could test only one?

 

What version of firmware are you using?
depending on your settings you might or might not need both signals hooked up.

If you ground a pair of teeth out of you CAS then you can use only one signal to get a rpm reading.
If you did not then you should have both of them hooked up as stated above. and the trigger setting set up as the FAQ says. If you dont have both signals hooked up and your trying to use the dual trigger mode the CPU will never see the reference pulse.

 

029y4 is the firmware I'm using. Do I need to make any MSQ changes and how do I ground it out. I just want to verify I'm getting signal on the Ne for now. As I just found a screw up on the the pins of my error board relating to the 2nd VR sensor. Sorry I may have mis understood you when you said grind out a couple teeth you mean actually take out a couple teeth not electrically ground them?

 

take a look at the FAQ it should help you with these problems you are having.

 

I definetly do not want to modify the CAS by taking out two teeth. I'd rather get the 2nd VR sensor working. I was just looking for an easier way to test one VR sensor at a time I guess I didn't realize that you needed both to get RPM. That's one reason I was hoping someone could take a look at my datalogs or tell me which signal I should look at for determining if my Ne or the G was not working.

 

i don't believe that you are going to be able to use the MS to check out the signals.. What you need is a graphical multimeter AKA oscilloscope to view the voltage waveforms of your VR signal.

 

Did I understand correctly? you've been testing with only G or Ne connected, but not at the same time? If that's the case, then you won't get RPM, there's nothing to sync to in one case, and there's nothing to provide e-shaft position in the other.

 

Yep, that's the case. I did not initally understand that you need both to check it. I found I had been using an incorrect pin and will be able to test it out wth both Ne and G friday. Hopefully becuase the G was not running it will work this time as Ne should have been working based on the ignition advance moving with only Ne connected.

 

Will a little progress but not much. The LED's won't flash or show RPM at start up. Randomly(beginning of start) though the tach on the car and megatune would flash an RPM. So I pulled the CAS and rotated it with my fingers and the rpm would shoot sky high and the fuel pump and I believe the injectors would click. It looks like I'm almost not getting any RPM at cranking to cause megasquirt to turn on and fire the injectors and plugs. Would this be because of grounding or the MSQ. Also tried it with a modified CAS and it would flash the LED's and turn on the fuel pump and injectors. Any suggestions? Plan on making a bunch of grounds tomorrow.

 

Could someone also help me stab the cas for 2 VR sensors. The original write up is no longer downloadable.

 

Cleaned and added grounds according to aaron cake. Still no signal trying MSQ's for both single and dual VR signals. I also believe I am stabbing it correctly. I fixed the two CAS's to a drill and would get the megasquirt to inject and fire plugs. Also adjusted the pots for the slowest possible running of the CAS for startup and still not startup during cranking. Really don't know where to go from here guys could really use some help. I reverified the CAS wiring and shielding ground. I think I am going buy some shielded wiring and run my own CAS wiring. I am really stumped. Please help me with whatever suggestions you have. The starter is dying on me and will need replacing soon. Could the starter being on its last legs be causing a lot of interference during cranking.

HELP!!!

Thanks

 

If you dont have a oscilloscope then you need to find someone who has one and knows how to use it. There are only a couple of things that can be wrong. Lets break this down (someone correct me if I'm wrong)

1. One or both Signals to the LM1815 circuit (aka VR signal amp) this signal comes out of the CAS and goes threw the db37 connector to whatever you wired it to (board or LM1815)
Diag : You need a oscilloscope to view these waveforms. so without this very important tool you cannot test the signal. Sorry ......You can test from the LM1815 circuit to the CAS to verify that the connection in the Board , wire , connectors are free of resistance and make connection to the devices.

2. A problem in one or both of your LM1815 circuits : This im not to sure how to trouble shoot this so maybe the MOD can chime in a little.... But from what i can gather this curcuit is a analog to digital converter. Which means that The signal from the CAS is turned from a sine wave at the LM1815 input and converted to a Square wave which is sent to the MS1 or 2 chip.

To troubleshoot either issue you will need a oscilloscope. You can probably get somewhere with A dvom but not far

 

Yeah, generally when I get the RPM spiking nasty like that, I put a .01 cap across the G+ and G- inputs where they come in and attach to the lm1815 circuits. You have to make sure that the G- wire is grounded as close to the lm1815 chip as possible as well.

Ken

 

Rewired the cas wires with some good shielded cable away from battery power. Had the same problems as before turning the CAS by hand would fire the injectors and plugs and it would not fire with the starter. Tried adding an engine starter with the battery to get more cranking RPM and it also did not help. I am working on trying to get a scope from work. I did not try the capacitor as I wasn't sure if you meant a 0.1 cap or um or pm 0.1 cap. I don't think it would matter though as we tried using the single and dual vr cas setups. Anything else. Would it be possible to have someone check the MS out? or anything else to troubleshoot before I get the scope. This is really been geting frustrating.

 

Ok for some reason the 2nd VR is not working so we just tried it with the modded CAS. New starter, grounded exactly like factory, with Megasquirt grounded to the block. Still cannot get it to start. Pulled the CAS turn it and it fires injectors and ignition. Ground it to the block and still works. Getting frustrated we tried hooking the CAS to a drill, grounding it to the block and turning the car over. Car started and even ran like this. Really am not sure what to try now. All grounds have been cleaned. With megasquirt grounded to block. Pots are turned all the way counter clockwise. Also tried with a bit of resistance on both or individually to with no effect. Would someone be willing to trouble shoot the unit for some cash? Any other suggestions. I did not try the cap on G as we could get the 2nd vr working for some reason.

Oh and haven't been able to borrow the O-scope yet.

 

I'm also using an RSAutosports Harness. These wires are the ground setup

12-15 Grounds brought together and grounded at one point on the block
16 Ground for the sensors (AIT, CLT, TPS)
7 VR -
8-11 Grounds crimped together to a large gauge wire to block

Let me know if maybe something there is wrong or should be tried differently.

 

If you're sure it's the second trigger that's not working, try adding the .01 uF cap across the G+ and G- wires where they connect to your second VR conditioner circuit.

Also make sure that G- is grounded as close to that circuit as possible.

Ken

 

Since the 2nd VR has not been working (circuit I believe), I have been only trying to use the modified CAS. Would also adding a cap across NE help? I'm still wondering what would allow me to rotate the CAS and start the car but not be able to even register RPM when using the starter. I am going to try one more way of grounding and using the O scope and if that doesn't work would it be possible to setup a hall and 36-1 tooth to run the ignition instead. I would turn an adapter and make my own mounts but I wasn't sure the software for rotary could work that way.

 

Put and O-scope on last night checked signal in block, with drill, with starter, at CAS, at MS, computer hooked up/unhooked, different grounding schemes. Signals were about looked good +/- .2 volts at cranking. Starting the car with the drill on the CAS produced more +/-.4 volts voltage but other than that signals were similar. No offsets - or +. Its almost like the starter cannot give high enough rpm = voltage. Tried it with a booster to see if that would raise RPM enough and it didn't. This is on a new starter. I am wondering if its the unit now or one of the pots is not working properly. Really need to have someone else check it out to see if it works.


Could a hall sensor be used with rotary code? Maybe a 36-1 tooth?

 

Try adjusting the sensor gap.

It'd work, but you shouldn't have to switch to that to get it to work.

Ken

 

How do you adjust the sensor gap? I'm assuming move the rotating assembly closer to the sensor by way of the 2 screw holes slop?


Also does this voltage (+/- .2 volts) seem reasonable for cranking?

 

I think it seems a little low. I don't usually measure it that way though.

I usually use a 2 channel scope, and make sure that the square wave output from the conditioner matches up with the VR output's zero-crossing points.

Ken

 

Awesome, took a look and the teeth were approximately 1/32 apart. Used a piece plastic bag to space the sensor and teeth. Started right up afterwards. As the sensor got closer to the teeth you can definetly feel the magnetism. So if you are having problems try to adjust the sensor closer to the teeth on the CAS.... Didn't get a chance to tune so I didn't go too high in the RPM to see if there was noise.