jmark06 Posted January 13, 2008 Share Posted January 13, 2008 I tried to set my timing before cranking my engine and had very sparatic tach signal the few times that I got one. I'm using an 82 dizzy to give the signal, wired according to DIYautotune. I got a signal sometimes when I tried to turn the engine (fuel pump fuse pulled) but usually nothing and sometimes when it did show something on the MS tach it would jump around and then go off. I rewired all the areas from the dizzy back that still had some of the old wiring and still have the same problem. When I hook it to the stim the tach seems to work fine. I went back to make sure everything was wired properly inside the MS box and noticed on the DIY website that the instructions say to use a 330 ohm resistor but the drawing shows a 1k resistor. I'm using a 330 ohm, is that a problem? It looks like my capacitor at C11 is fried so I need to replace it, but I don't know if that will fix the problem. I think I have everything from a software side set up correctly. MSns is set and only LED 17 set to Spark output. Spark is set to inverted YES and cranking RPMs set to 300. Voltage is good in crank and run. Any ideas? Like I said it seems to sometimes work, but most of the time nothing, I'm hoping the capacitor is the problem or maybe I'm using the wrong resistor. Quote Link to comment Share on other sites More sharing options...
jmark06 Posted January 15, 2008 Author Share Posted January 15, 2008 Any suggestions? should it be 1k or 330 ohm? I think that the capacitor is OK but I'll replace it anyway. I'm really frustrated with it. Quote Link to comment Share on other sites More sharing options...
olie05 Posted January 15, 2008 Share Posted January 15, 2008 Did you make sure the distributor is getting power while cranking? Quote Link to comment Share on other sites More sharing options...
jmark06 Posted January 16, 2008 Author Share Posted January 16, 2008 Yes I have 12 volts to the distributor during cranking. I've checked all the wiring from the distributor back and it's all fine. Now I can't get the engine to turn over, I think it's because my battery is too dead to turn the starter. It turned over on the first try after I charged the battery for a couple of hours, but hasn't since then. On that first try though the tach in megasquirt didn't work at all (or my car tach for that matter). I want to check the signal wire and see if it's gettin gany voltage during cranking to make sure the CAS is working correctly. If it is, which I will find out tomorrow, then I must have a problem with the megasquirt I'm guessing. The car was running fine with the old computer so my thought was that the CAS was OK. I just though it would be some kind of loose wire issue or something since it works sometimes and others it doesn't. But all of the wiring checks out when I test it with my multimeter. My hands are bleeding and I'm cold and frustrated, any suggestions? Quote Link to comment Share on other sites More sharing options...
olie05 Posted January 16, 2008 Share Posted January 16, 2008 yeah, you should take the distributor off the engine and spin it by hand while monitoring your laptop. you should get a tach signal. trouble shoot for loose or whatever until you get a signal. Quote Link to comment Share on other sites More sharing options...
jmark06 Posted March 2, 2008 Author Share Posted March 2, 2008 My starter was no good and I replaced it so the car turns over no problem now. I eventually decided that my CAS was the problem so I bought a new one. STILL NO TACH SIGNAL on MS. I checked and I have 12V going to the red wire, the black wire is grounded, and the signal wire is connected to the white wire. I have the 1k res wired into the MS board as per DIYautotune.com. I pulled the distributor out and wired the 12v and ground wires up and put a meter on the output spade. No voltage when I turn the shaft. Maybe I somehow got the wiring mixed up when I was rewiring everything. Does anyone know which spade is what on the CAS itself, not referencing the old wiring. I'm running out of ideas. The tach works fine with the stim board hooked up. Quote Link to comment Share on other sites More sharing options...
evildky Posted March 3, 2008 Share Posted March 3, 2008 moby's writeup has all the wiring info you'll need Quote Link to comment Share on other sites More sharing options...
mobythevan Posted March 3, 2008 Share Posted March 3, 2008 The sticky lists the wiring color codes for both sides of the harness to the CAS, because they are different on each side. Quote Link to comment Share on other sites More sharing options...
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