I have a '87 T2, running stock componints so far, I bought the MS pre built. I built the daughterboard and installed it. Both coils came out of a running car, and the CAS meters fine per the FSM. I am running a un-modded CAS, which has never been pulled, so timing should be ok. The ms is a Ver 2.2 with the new firmware in it, The car has a complete custom harness, and both coils have power, the CAS is wired per the FSM (ne+,ne-,g+,g-). The MS shows all of the sensors working properly (bat voltage, clt temp, iat temp, and tps). I do not have my .msq here, it is on the laptop in the car 2 hours away. Does someone have the equipment to bench test the daughterboard for me? At this point, it seems the odds are best that it is where my misake is.
Thanks,
Chris

 

If you're getting an rpm reading on the MS, the problem isn't in the daughtercard.

Did you remember to put pullups to +5v on each of the negative leads of the LEDs?

 

Yes, the pullup resistors are in. I thought the rpm will not read while cranking anyway? Trailing Ign does not fire at that low of a rpm?? Am I mistaken?

 

You should get rpm's in MegaTune, but likely not on the dash.

 

I am showing no rpm while cranking. Once, the tracer needle was pointing to 24, but that was 1 time, and I do not know why it was only 1 time.

 

IF you're not getting RPM during cranking, that is why you're not getting spark. The MS doesn't know the engine is spinning.

You're going to have to figure out what's wrong with the wiring and VR sensor conditioner setup from your CAS to the MS.

 

i was having the same problem a week ago and i found out my starter was getting stuck
but thas not what causes it to not get singnal its the load the starter consumes that makes the signal weak try pulling the cas out and turn it with you finger and im sure it will fire but make sure u unplug the ign wires and look at your laptop u will get rpms and if u dont the u have another problem, one time the conection to the number 11 pin on the main prosesor
got desolder and that was it, hope my mistakes help u out

 

Did you guys tie the tach signal input into the trailing coil? It is one of my questions.

 

no. Why would we do that? The tach signal when running the MS as a standalone comes from the CAS only.

 

Could that cause my problem? do you just leave that pin blank then?

 

You say you got the MS prebuilt... did you build and install VR sensor conditioners for it?

 

wow. you must have mixed something up pretty badly. go back and reread the faq at the top of the page. there are diagrams in the faq page that tell you specifically how to wire the vr ciruits into the ms. what i suggest is you put it down, and start testing it from the basic components to the final product. maybee a wire is soldered in the wrong place, bad solder points? could be anything.

are your wires to the cas shielded? are the sensor in the cas good? ( strong resistence when turning the cas?) are the gapped properly? are you stabbing the cas properly?

try spinning the cas by hand and watch to see if you get an rpm.

 

I went and worked on it last night, the CAS reads 175 ohms on both G and NE circuits. I removed the tach input on the db-37, my mistake on that one. The MS reads both cranking and runing when I spin it by hand, but only when G (2 tooth wheel) passes by the the sensor. When i turn it between those teeth, nothing. I am still showing no rpm on the runtime display. I am using the stock shielded wire through the engine bay, but the last 2 feet after the firewall are un shielded. I traced the wires back to the daughterboard, and I am showing the 180 ohms from the CAS on both VR1 and Vr2. I think I have ruled out all of the other possibilites but a bad VR circuit. Can someone look at it for me? I am willing to pay for the service. Thanks.

 

If it doesn't read rpm until one of the teeth on the 2 tooth wheel passes the G sensor, then it's working the way it is supposed to.

The MS uses the G teeth to "sync" so it knows where tooth #1 is.

Basically what you're telling us tells me that everything is working as it should.

 

It does not give me a rpm reading though, it just flashes both "cranking" and "running". Is that normal without a rpm reading?

 

it shoud read an rpm. maybee it was a setting you dont have correctly configured. are you stabbing it correctly? are the settings for the 2 tooth wheel setup correctly?

 

I did cut any teeth off of the CAS, so I do not fully understand what you mean about stabbing it correctly. All of the spark setting I got off the FAQ. The car is 2 hours away from where I live, so it gives me alot of time to think about it. What would the MS do if I got the NE+ and the G+ reversed (in other words, VR1 and VR2 switched)? Just another idea. I have the MS with me in case someone can bench test it for me. Thanks for the ideas, and helping me to troubleshoot it.

 

if you got ne and g reversed it might do what you're seeing.

Can you post an msq just for sanity checking?

 

yeah. if you have them reversed, you wont see anything.

 

Next time I go and work on it, I will bring the laptop back so I can postup the .msq. Thanks again for the help.

 

I am using a 2.2 board 029n4 with Error's daughter, and have an interesting problem related to this thread. While cranking, I get no RPMs, but if I turn it by hand, they appear. When I use a drill to modulate the speed, I can only get up to ~100 RPMs before it stop working (goes to 0). Both pots are fully CCW, and register 9.5k (away from LM1815) and 0.2 (close to LM) resistance from center to each leg.

Thanks,
Pete

Attached is the msq

 

I just got off of work, went and worked on it last night after work. Have not slept yet, so I will keep it short. I had NE+ and G+ swapped in the harness I am useing to go into the MS case. I re-pinned them at the CAS to swap them, and we got spark. YAY!!!!!!!!!!!!!!!!!!! Thanks for everyones help.

 

you are using shielded wires aint ya?

 

I'm using the factory harness with a short adapter going from the stock ecu plug to the db37 and a db25 (contains the CAS signals, Aux port out, and VDI out). I have been checking lots of stuff, and noticed that I have an in-line resistor on the CAS G- which isn't on any of the reference wiring diagrams. I'll try jumping that to see if anything changes.

If the MS works well, I will be building a custom harness with shielded wire for all signals, but since I race the car 2-3 times a month (autocross and DE track days), I need to be able to switch back to the stock ECU until the MS is properly tuned.