boardkid280z

I bought my V3 board kit at DIYauto.com and am running all the standard hardware that comes with the kit, I also setup the board to directly fire the coil. I did not set up a flyback board for my injectors, nor did I wire in any resistors for the low impedance injectors from an '81 Turbo ZX. From what I understood when installing MS, the V3 board did not require a flyback board and will directly run the injectors without a need for reducing PWM <100%. So I have the injector opening time set to 1.0ms, PWM Current Limit (%) is set to 100% and PWM Time Threshold is set to 25.4ms (I think that's the default). Do these settings sound right for the V3 board and MS1 I have? A problem that developed about 2 weeks ago is that suddenly the car would not stay running and I had not changed any MS settings. To get the car running, I had to UP the "req fuel" (ms) setting from the 12ms it was at for the 270cc injectors to 23ms (about 135cc injectors). So basically I had to double the fuel. It ran fine like that, took a little tweaking again to get everything set right, but since then the fuel req has been 23ms instead of 12 like it used to be. Any idea what might have caused this?? I am completely stumped, and a little worried that there is still a problem somewhere. Any suggestions are welcome!

I had to do that too to get mine to working right... I think because of the way I wired the spark output on the bottom of the board.

Another place I found that sells them for a decent price is these guys: http://store.racing-solutions.org/index.html Great service and fast shipping. I got the 3" exhaust builder kit - comes in aluminized steel. I used a 180 and one 45 degree bend for the downpipe, so i still have another 180, two 90's and a 45 to finish the rest of the exhaust. Bought the O2 bung from them two.

Well, there may be a problem with your board. But as we figured out, we had the TPS wired wrong and had to mess around with it to get the right signal to MS. 240SX TPS have 3 wires, correct? Confirm which one is ground and make sure it is connected to the MS ground wire, then test the other two (sounds like you've done that though)... you might try switching the two that aren't ground. Mine wouldn't read right one way, but worked fine the other way.

http://students.oc.edu/matthew.brazle/pages/1stsparkrundos.msq running msns-extra.s19, 024s13c. on a V3 board. This is my current settings-file, of course I am continually tuning, but after 4 days of running, it is running pretty good. Setup: Flattop pistons P90 (turbo, non-hydraulic) head and cam Stock 1981 T3 turbo Stock Turbo injectors - 270cc Stock FPR 1987 Supra intercooler 280ZX N/A distributor, no mechanical advance. (ignition module E12-80 sends tach signal to MS) Let me know if I need to add any more info.

Well, you gotta watch out when you just switch the spark output from inverted to non-inverted and back. When I set mine to inverted, it thought it was getting a constant signal from the distributor to fire, so it was sending a constant signal to fire the coil, this made the LED stay on all the time. This also made the coil driver transistor get VERY hot. So when the car is off, inverted or non-inverted (depending on your setup) might make that get very hot because of this, so watch out for that.

You can buy harnesses on ebay. The one I got came with quick release connectors for the injectors and came with a coolant sensor and Air temp sensor and GM connectors for them and for a TPS. Great package. Not bad for $100.

On ZCar.com http://www.zcar.com/forums/read.php?f=1&i=651451&t=651451 there have been two responses, basically saying: 1) the flow rate out of the injectors is constant at constant psi (no matter what the air pressure is, so it will be much easier to tune MS with a constant psi. 2) at boost the intake manifold pressure pushes against the fuel pressure and reduces flow from the injectors which is why the stock FPR increases fuel pressure as the boost comes on, which is what you need. Is one of these wrong and one right?

(as posted on zcar.com) - I was wondering what fuel pressure you guys are running with your Megasquirt setups. Both N/A and Turbo, but specifically turbo since that is what I am doing. Do most of you keep the stock FPR and program the MS to work with that psi? Or do you have an aftermarket FPR that runs constant psi? Or do you have an after FMU that raises fuel pressure with boost? (and from what psi to what psi?) Thanks guys. I am thinking of running an FPR off of a Turbo Dodge van at 55psi with turbo ZX injectors and just program the MS for that constant psi instead of messing with rising rate. Seems like MS will work better like that.

There's one in the classifieds by mobythevan

Well, the P90 and dished pistons have lower compression (7.?:1 - ) and have a lower pressure on compression test. 140ish instead of 170ish. The P90 on Flattop pistons instead of dished will raise compression (8.5:1 or so) and I believe it will also raise the pressure during a compression test, so I wouldn't worry too much about shaving the P90. That might even be a bad way to go. Just my interpretation - I have done some thinking about this myself since I am doing the same thing soon. P90 head on flattop pistons. With turbo.

but I don't have MS yet, I am getting everything ready to convert my 78 to turbo and will go with Megasquirt and Spark at the same time. Where are you at? once I get mine up maybe we can look at eachother's and help with tuning. And I might have some questions for you, if you don't mind. -Brazle

The P90 is the newest L28 head that came in the Z car. (new=more advanced). From what I understand it outflows the previous heads which is part of the reason it is more desireable. A second reason is because it has the heart shaped quenching combustion chambers for better combustion. Do a search on www.zcar.com for P90 and N47 and N42 and Maxima N47 and MN47. There have been MANY discussions about these heads and which ones flow better. Lots of information there.