mikeatrpi Posted November 2, 2008 Share Posted November 2, 2008 I am adding a turbo to my 82 280zx NA engine, using megasquirt. Its a MS1 V3 PCB. I'm using a locked VR distributor, and plan to use MSnS. I have about half the wiring done - Datsun CHTS, GM IAT, TPS from a Quest, etc. I don't have the coil, injectors or fuel pump attached yet. I installed the MS in the stock ECU location. There was a plug there with a single lead that I'm using as my switched 12v source - it has power in RUN and CRANK. But - there are two wires on the 280zx coil. If I disconnect them, that switched lead no longer works. So, what should I have attached to the coil? There's a stock wire on the +, do I keep it? Another stock wire on the -, ? [side Question - is this for the Tach?] I have a 12v + from the fuel pump relay, not yet attached. Should I? The IGN OUT from the MS for the - ? Thank you!!! PS I'll be back with more questions and pictures soon Quote Link to comment Share on other sites More sharing options...
evildky Posted November 3, 2008 Share Posted November 3, 2008 I'm not sure how the n/a is wired but I believe the hot on the coil is a part of the chassis wirign and you cna keep it to power your coil, the negetive I believe goes to the stock ecu as well and the tach, if it doesn't go into the engine harness then I suppose it just feeds the tach and you cna leave it in place, as for powering your MS, first and formost wire up your hot power, to the battery , then take your switched power form wherever you like, it's realy just a trigger signal to turn the unit on your stock fuelpump relay should still work you'll just need to pull the trigger wire out and run the ms fuelpump trigger wire to the trigger side of the relay Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 3, 2008 Author Share Posted November 3, 2008 Thanks. I'll leave the stock + and - wires on the coil, and add only my spark out (pin 36) to the - side of the coil. I just realized I never connected pin 15 of the DB37 to ground, per the MSnS instructions. So I have to do that. Other questions: 1. I'm using the GM IAT and the Datsun CHTS (with values from the sticky). They are reading about 8-10 degrees F different. The IAT is pretty close to the air temperature... but the CHTS is colder. Should I try for a more individualized customization or is this normal? The car hasn't been run yet (meaning I'd expect the block and air temp to be close to the same) 2. Trying to calibrate the TPS. I ran their wizard and got some numbers. How do I "save" these? 3. Should "Fetch from ECU" and "Send to ECU" in the various MS menus change things? It seems like "Fetch" doesn't actually do anything. I want to make sure my settings are making it to the ECU. MANY MANY thanks!! Quote Link to comment Share on other sites More sharing options...
mobythevan Posted November 3, 2008 Share Posted November 3, 2008 2. Trying to calibrate the TPS. I ran their wizard and got some numbers. How do I "save" these? I usually open up real time display on a new install and see if the throttle position shows zero when off the pedal and 100% when pushing all the way down. If it doesn't, then I go to their calibration tool. Don't touch the pedal and get the closed throttle count. Push it all the way down and get the full throttle count. Then close out of the calibration window and then shut down megatune. It seems to pick up the settings when starting up megatune again. Re-start megatune, go to real time display and make sure it shows zero when not touching the pedal and 100% when pushing the pedal. If so then calibration worked. That has always worked for me. 3. Should "Fetch from ECU" and "Send to ECU" in the various MS menus change things? It seems like "Fetch" doesn't actually do anything. I want to make sure my settings are making it to the ECU. Fetch will just bring back whatever values are loaded into the megatune screen you are viewing. To test it open up the spark table and type in 15 degrees of timing in several cells that have some other value, do not burn them, now hit fetch and see that the original values are restored in the spark table. Once you hit burn that is what will be fetched next time. I try to always make sure I burn the values and save them at the same time so I don't end up with a saved file that doesn't match what was burned. Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 3, 2008 Author Share Posted November 3, 2008 Moby thanks! I calibrated the TPS, restarted megatune and rebooted the MS. The values stuck. I added 3 to the closed, and subtracted 3 from the full to absorb some variance I noticed trying this several times. I now have a working TPS signal!! I also just got my RPM to register from the VR input by adjusting the pots all the way counter clockwise. I'm using a locked distributor directly into the MS v3. I have some more wiring to do and I need to get #1 to TDC so I can clock the rotor properly. Thanks again!! Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 3, 2008 Author Share Posted November 3, 2008 Regarding the fetch and burn - its almost like it automatically sends the changed values to the MS for me. In the spark window there were two red messages - unsent and unburned (or something like that). From the manual it looks like it puts my changes directly to the RAM but does not burn them to the flash unless I tell it to. Quote Link to comment Share on other sites More sharing options...
mobythevan Posted November 3, 2008 Share Posted November 3, 2008 Regarding the fetch and burn - its almost like it automatically sends the changed values to the MS for me. In the spark window there were two red messages - unsent and unburned (or something like that). From the manual it looks like it puts my changes directly to the RAM but does not burn them to the flash unless I tell it to. Yeah, that must be correct. I am not sure what good fetch does then?? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted November 3, 2008 Share Posted November 3, 2008 I boiled my CHT sensor, checked it at room temp, and put it in ice water. With this method you get a near perfect calibration...or at least good enough to run an automobile. They are not super critical sensors anyhow. + or - a few degrees isn't going to make a big difference. The fuel correction maps will sort out any small differences when you tweak the correction curves. Just get the sensors data input reasonably close, so your maps and others can be shared. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted November 4, 2008 Share Posted November 4, 2008 Yeah, that must be correct. I am not sure what good fetch does then?? If you have made changes to the VE table but not burnt them to the ECU, Fetch returns them to the values currently in the MS. Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 8, 2008 Author Share Posted November 8, 2008 So I'm back in the garage today trying to get the timing set. I put the motor at TDC - checked for the compression stroke with my finger over the #1 hole, then I kept rotating until the timing mark was at 0. My rotor isn't pointing directly at the #1 location under the cap - its a couple of degrees past it. I loosened the screw beneath the rotor but I couldn't actually rotate anything to get it better lined up. I'm hoping this is something I can take care of with software? My rotor has a little bit of wiggle room in it. I can move it a few degrees. Is this the mechanical advance or just slop in the gears / shaft? I don't see the plates move that I welded up. Then, I forgot to ground pin #15 on the DB37 connector. So I did that, but I accidentally shorted it to +12v. Something smelled bad briefly... so I think I blew out something on the board. Whoops. Always disconnect the battery. Any hints what I might have blown up? Feelin pretty bummed. Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 8, 2008 Author Share Posted November 8, 2008 Yes I think I broke something on the board. MS resets dozens of times while cranking. With the coil - line from MS disconnected, it cranks fine without resets. Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 8, 2008 Author Share Posted November 8, 2008 I think it was Q19. I know, nothing related to spark output. But it had blown some goop out the side and smelled pretty bad. So, I replaced that, and it still resets while cranking with the pin 36 attached to the - side of the coil. It runs fine on the stim. Is there a way to test the coil output while using the stim? Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 8, 2008 Author Share Posted November 8, 2008 How's this for play by play? I theorized that since my 12v switched input to the MS relays was driven from the coil, when I tried to fire the coil I lost my 12v. Therefore I jumpered it to 12v so the relays would always be on. That fixed the reset problem... I'll move it to a different 12v source later. Now, I'm not getting much in the way of a spark output. With my timing light, its like blink-blink-nope... blink blink nothing... Time for more investigation. Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 8, 2008 Author Share Posted November 8, 2008 Holey moley... she idles!!! After reading for the last two hours, I decided "WTH" and hooked up the fuel pump. She fired on the 3rd try... I played with the trigger angle and settled at 73.5 degrees +45. Video or pics or something coming soon!!! Thank you all for enduring this little soap opera... Quote Link to comment Share on other sites More sharing options...
mikeatrpi Posted November 8, 2008 Author Share Posted November 8, 2008 Here's two logs and my MSQ. The first log shows the car starting (not from a cold start), and the second shows it already running. Its almost like my idle is a little bit low - it smooths out when rev'd up. Also, I still need to do some work on the timing. You can see in the logs that the RPMs hop around. The timing mark is reading around 0 with it set at 10 degrees. I tried adjusting my trigger angle but it seemed to make it run rougher. I'd appreciate any advice... first_idle.zip Quote Link to comment Share on other sites More sharing options...
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