OhBilly

I used the relay board and wired it up exactly like the install article at DIYautotune: http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_280zx_turbo.htm The relay board has really made everything straightforward to wire up. I know if I didn't use it, everything would be a mess.

If you are using MS1 Extra, it has provisions for driving your coil directly. In other words, there's no need for an HEI. Have you found the 280ZX turbo install article at DIYAutoTune yet? Check here, this may answer a lot of your questions: http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_280zx_turbo.htm

Just an update to let you know I got both banks of injectors to fire. The problem turned out to be a bad soldering job on my part on a few of the tiny transistors in the injector output circuit. The troublesome ones were Q13 and Q15. I discovered the problem by using a multimeter to Ohm them out. Sure enough, a few of the leads were shorted, and they were shorted on the top side of the board, directly underneath the transistors. The offending bits of solder were so small I had to use a good magnifying glass to see them, and since the were shorted under the transistors, I had to pull them up and off the board to do so. If you haven't checked out those tiny transistors yet, I'd give that a shot. I thought I was super careful soldering those things on, but they are just so tiny it's easy to bugger them up without knowing. Thanks for letting me hijack your thread. Good luck to you. Matt, thanks for the help, I appreciate it. Bill

MSQ is attached. Thanks for the help Matt. Bill rustbucket_9-12-12.zip

Matt, thanks for the reply. How can injector bank 2 be shut off? Under "Advanced" and then "Fuel Table Selection" I see you can select Table 2 for INJ2, but I have mine set to Table 1. Is there another way it can be shut off? Thanks again.

Did you ever make any progress on getting bank 2 to fire? I am in the same situation... bank 2 not firing. Like you, I don't have a noid light nor a stim. I do work with some smart electrical engineers though, and we have scopes, power supplies and multimeters that I have access to in the lab. Matt Cramer, without a stim, how would we go about testing the injector driver circuits? As a side note, why does it always seem that bank 2 has trouble? Thanks, Bill

Hi, Looking for a Megasquirt Stimulator. Just trying to save a bit of money by not buying new. Thanks, Bill

I'm looking for someone who can physically troubleshoot and repair this board. Any takers? I can ship the board out to you and of course, pay you for your time and materials. I just don't have the time and skills to do it myself. I'm working in the Aurora, IL area and living near Joliet, IL if anybody is close enough to avoid having to ship. Thanks, Bill

Matt, I am jumpering the bootloader contacts for my attempts, but maybe the way I've done it is part of the problem: To avoid having to remove the case cover, I soldered wires to the bootloader contacts (1 wire each) and routed them outside the case. To jumper the contacts, I simply twist the ends of these wires together. I don't see any reason why this wouldn't work, unless the wire lengths are too long and there's too much resistance in them.

Thanks moby, that helps... and it makes sense. The poster must have got his pin numbers mixed up. The MS box is getting power for sure because if I power it up without the boot loader pins shorted, the ECU comes to life: the fuel pump primes for a few seconds, and the LEDs on the MS box light up (IIRC, one light blinks for a moment and then the middle LED lights up solid and stays that way). If I keep power going to the MS box this way, after about 10 seconds or so, the relays start chattering like crazy. Should any LEDs light up when the bootloader pins are shorted? If so, I don't get any. Is there anything else that I should be checking? If I can't get it to work, I'll likely send it off to DIY for troubleshooting.

I just finished building a new MS1, V3.0 and have got it installed in the car per the instructions in the install article on DIYAutoTune (I'm using the relay board): I am attempting to download the MSnS-Extra firmware to the ECU but I'm not getting very far. After shorting the bootloader pins and turning on the ignition to supply +12V power, I'm getting an error basically saying Expecting "boot>", Received " " once the download attempts to start. I've done a bit of research trying to figure out the reason, and one thing I came across is someone mentioning that this issue is seen when you are not supplying +12V to pin 24, or in my case since I am using the relay board, connection #15 in the above schematic (TACH line) on the relay board. With the ignition on and bootloader pins shorted, I checked the voltage at this connection and sure enough, it reads in the millivolt range, not even close to +12V. I couldn't realize how this could be until I remembered that there's a 1K ohm resistor between my switched +12V source and the TACH line, per the DIYAutoTune instructions. If I check the voltage prior to the resistor, I do indeed read about +12V (I don't remember exactly, but I think it read about 11.5V). Now, the question is, should I be shorting that 1K ohm resistor in order to get the firmware to download? If this would work, would doing so cause any damage to the distributor ('83 turbo dizzy) if it gets a full +12V rather than the millivolts it would be getting with the 1K ohm resistor inline? Of course it's easy enough to disconnect the connection to the distributor if needed, but I'd rather not do it unless I need to. Thanks for any advice, Bill

There's a sticky in the FAQ section that says to use the same settings as those for the DSM 450cc injectors: Injector Opening Times Spreadsheet Hope this helps. Bill

DIYAutoTune.com sells prebuilt and complete boards. And no, you don't have to have everything working and receiving a signal for the complete unit to function.

Thanks Matt, that helps a lot. I've been reading a bit more and things are slowly becoming clearer, but it's definitely not easy... at least not for me. It seems there are multiple ways to make things work and that's part of where my confusion comes from.

Nope, I'm not quite that bright. But now I have another dumb question: Is R12 actually the pullup resistor, or something else? I just did another quick search and somebody mentioned that R12 IS the pullup resistor. Right now I have a 390 ohm resistor in R12, but MSnS says that for a 12V CAS the value of R12 should be 1K. Does R12 need to be 1K, plus "another" 1K pullup? Thanks again.

Well, you're probably right, but I don't think these schematics have anything to do with the CAS output voltage, do they? The schematics tell you what wires need 12V power going to them for sure. But in reading about the Hall PCB wiring, it discusses Hall sensors and that some of them are 5V and some are 12V. It says that 5V CAS are more common and says if you are in any doubt, start with the 5V assumption and go from there. It also gives you directions for determining if your CAS is 5V or 12V, but it involves actually having the dizzy hooked up with power going to it. My dizzy is buried in the garage somewhere, probably hiding underneath some oil stained t-shirt. Like I said, you're probably right (and thanks for the help) but I don't see how these schematics tell me what I need to know. Maybe I need to go back to MS school? Bill

I've been searching and haven't come up with an answer yet which leads me to believe that I'm either an idiot, or everybody else intuitively knows this. Or maybe both. Anyway... My PCB is nearly built, just have to finish it off with wiring up the Hall trigger. According to V3.0 assembly instructions on the msextra site, I need to determine if the internal CAS is 5V or 12V. This will determine what jumpers I need to install as well as determine the value of R12. I've followed the instructions on DIYautotune for their 280ZX turbo article which has helped a lot, but I can't seem to find this crucial bit of info. Any help would be appreciated. Thanks. Bill

Mine works the same way on most days!

No problem, just let me know. I have lots of other little issues to solve in the meantime anyway. Thanks again.

Now that's what I'm talking about! Cool, let me know if you can find it or not. Thanks. Bill

I hadn't, but just did. Our local hose supplier didn't have anything, and napa's hose is only good to 200 deg F. Good tip though, thanks for pointing out what should have been obvious to me... check local first.

I need maybe 4 inches of the stuff to complete my oil drain, but I'm having a hard time throwing down $8 plus $10 shipping for a foot of it. Anybody have any leftovers lying around the garage they'd like to sell? Thanks, Bill

A place called connectorsfast.com sells them and it ends up about $50 shipped. I found a new set yesterday on ebay from a vendor called osidetiger. Total shipped cost was $34.60. We'll see how they look...

Did you ever get around to testing this?

Thanks for the offer, but I can get a set of new ones shipped for that price. I'll keep looking for a cheaper set... Bill