MSII installed running in 78 N/A 280z stock wiring

[twoeightythreez]

First, a big shout out of thanks to HybridZ and Mobythevan. Still got a lot of work to do but without this site would still be scratchin my head.

I apologize outright...don't have any pics but still worthwhile as I'm gonna give you my VE table and ignition map. Will get you running with torque. How much? How about being in a .75 5th going up a steep hill at 800rpm and actually feeling acceleration sound? If interested read on. The tables aren't perfect but low rpm rocks (though my brakes hate me now, I burned them up as the L28 with dialed in timing makes TONS OF TORQUE, actually more than the brakes can hold. Seriously.)

My accel wizard hasn't been touched yet, so you'll have to figure that one out.

First, the install into the car. I used my stock wiring harness so I'll detail the install for those who would like to know.

The stock ECU connector is an AMP and can be easily disassembled. There is also another 4-pin connector that ties the ECU harness with the body harness. If it's a cali Z then there is also the altitude switch 2 pin connector. Lotsa tape and u see the wires. They are numbered every few inches just like the MS wire harness. Here's the pinout/color/purpose in a 280z.

1/B/Coil (actually goes to the 4-pin connector, more on that later)

2/B/TPS #2

3/B/TPS #3

4/G/Start signal to stock ECU not used in Megasquirt

5/B/ Ground

6/B/ AFM #6

7/B/AFM potentiometer

8/B/AFM

9/B/AFM

10/L/Switched 12VDC from ignition relay...more on this cluster later

11/not used

12/B/to altitude switch-not used in megasquirt

13/B/H20 temperature sensor signal...2500 ohms at 80 deg F

14/B/Injector #4 switching pulse

15/B/Injector #1

16/L/GROUND..has a bit of yellow paint on the end

17/L/GROUND..has a bit of WHITE paint on the end

18/B/TPS middle wire (I put this to ground on MS-II)

19-not used

20-not used

21-G/Cold start injector 12VDC comes from 4-pin connector Can be reutilized as in my install

22-not used

23 thru 26 also not used

27/B/AFM

28 and 29 not used

30/B/Injector #5

31/B/Injector #6

32/B/Injector #3

33/B/Injector #2

34/G/Air regulator 12VDC lead I reutilized this (without the 12VDC naturally)

35/L/ GROUND..has a red mark on the end by the "DB-35"(datsun-bullcrap 35pin) connector

 

Ok those pins are installed (in my install) to these DB37 pins on the MSII, pins I relocated, etc. I'll explain since I have no pics.

On my preassembled DB37 pigtail, pins 1-6 and 10-16 are not used.

7,8,9 goto one ground wire. I put the all the datsun grounds together, plus some others I'll explain as it comes up, to these wires. Basically all the underhood grounds go to my megasquirt. I also made sure I put lots of extra ground straps to the body to make sure.

 

17,18,19, same thing, all the grounds go to the datsun grounds.

 

20, IAT sensor. I used one of the AFM wires to go to this pin, another went to the common ground. The IAT itself was a push-in unit from a 89 grand prix, fits in the stock TB boot like a glove, just have to trim 1/4" off the nipple so the IAT is exposed to the moving intake air.

 

21- to datsun wire #13. the other side is already grounded. No worries. Just don't make my mistake and hook into the thermotime wires instead. The temp sensor has the white bosch connector and the thermotime has the brown one. It took me an hour to figure out why no temp signal was getting to Megasquirt! Sometimes the problem is right in front of ya.

 

22- TPS signal to Megasquirt- I used datsun wire #2 for this

23-o2 sensor input. Naturally you have to install an O2 sensor and wire. I used one of the altitude switch wires (since my car is a CA smog special) so it would be a nice clean harness, plus I can disconnect it and plug a wideband into the ECU when the real tuning starts. Free connector, too.

24-power to the optical dizzy I used. I just tied this into datsun wire #10

25-IAC 1B wire. I put this onto datsun #34 (air regulator) No 12V on it anymore. This wire used to supply 12v ign power to the regulator.

26-5VDC reference voltage. I put this one on Datsun wire #3 (TPS)

27-IAC 1B- I put this on datsun wire #21. Another power wire this one for the cold start injector. Not anymore, now that I have a stepper motor for cold idle

28-switched 12VDC to Megasquirt. To Datsun wire #10

29-IAC 2A- This wire comes from the 4-pin connector that come from the right side of the car. It's the only connector that plugs into the ECU harness. Hope you're good with a multimeter. If you don't use IAC just leave it disconnected. No harm done.

30-FIDLE "-" output. I didn't hook this up yet. Plan on using it for electric fans. Need to run a wire across the inside of the car and connect to one of the VR wires (to the stock IGN module..more on this later)

31-IAC 2B same as 2A. Trace wire on ECU end of 4-pin connector, hook it up. If you use these you have enough wiring, I didn't add a single wire.

32and33-Injector bank 1- I hooked these to datsun pins 15,33,32 (injectors 1,2,and 3)

34 and 35- Injector bank 2- to datsun wires 14,30,31 (injectors 4,5,and 6)

36- coil negative wire. MSII can run a coil. To datsun wire #1 This wire goes to the 4-pin connector. If you wire it up the way I did you have a nifty anti theft device, as once you're done you can just disconnect this 4-pin connector (which will only have two wires left if you used IAC) as once it's disconnected you will have no fuel OR spark. Neat.

37-fuel pump relay trigger. There is a little bit of re-wiring involved here.

On the 4-pin connector, find the G/L wire. Make sure your battery is disconnected and make a long jumper wire for your multimeter, hook to this wire. Then go under the hood, passenger side and unbolt the metal box the fuse links are mounted on. Underneath this box you'll see a bunch of relays. Unplug the one farthest left. It's the ignition relay after the first ignition relay. The wire is in the middle of all the blue and blue/white wires. The one you get continuity on with your jumper is the one you cut and label. Now find the fuel pump relay, it's the small one with the 12-gauge L/G wires on it. Cut the black wire (ground) and splice your other wire to it. Cut the W/B wire going to the other side of the field coil of the FPR and splice it into the fuel pump power wire. (You'll have to plug in the battery to test for which one has power all the time.) The reason for this is the white/black wire is a START signal, and don't be tempted to just tie into the white/black that's on the 4-pin ECU connector, as it's powered from the main ignition relay. I didnt want to find out what would happen to MS if 12v got applied to the fuel pump turn on. Probably not good. OK almost done here. Now, unplug your voltage regulator and have an assistant cycle your key on and off till you find the 12volt switched power from the alternator. Splice into this wire and connect it to the wire you cut first for the ignition relay. If you don't do this you'll be scratching your head for hours because your Megasquirt will have no power but everything else will. It was annoying.

Ok hope you heatshrinked everything as these wires are outside and under the hood, the worst place imaginable. Button it back up, test your pins, and it's time to hook up megasquirt! The unit fits nicely where the stock ECU once resided. The factory ECU cover will even fit over it for a stock look.

 

Now you're done in the car, time to hook up the stuff under the hood.

The TPS red wire (240sx or stanza) is the Vref.

THe White wire is the signal,

the black wire is ground.

 

If you're using an optical dizzy the red wire is the 12VDC,

the white wire is for Megasquirt, and the black wire is ground.

Don't use the green wire.

While you're wiring this up you might as well put the pullup resistor in. Just get a 1 to 1.2K ohm resistor and connect it between the Red wire and the White wire.

 

Hooking up the IAC motor

Make sure you labelled your datsun wires so you can hook this up. The MS manual details the wiring of the IAC, this write up is how to install IAC onto a 280z manifold.

1) You're gonna have to mod the throttle body and intake to make this work right. It's actually really easy. Since you're gonna get shavings all over you might as well renew the intake gasket and buy a 60mm throttle body. My mods detail the MSA bolt-on stock-style TB if you have a 240sx piece you're on your own. This mod naturally will also work with the stock TB.

On the TB, remove the stock idle bypass screw, and drill and tap the seat to accept a 1/8 NPT pipe plug. Use epoxy on this so it never comes out (at least if it does you have a leak it'll never fall into the motor)

Drill out the threads for the bypass screw and tap it for a 3/8 NPT.

Screw in a 90 deg nipple into the modified passage.

Now you can hook a hose to the one end and the other already has a nipple on it from the stock IAC set up. Since mine was messed up I tapped that hole for 1/8 NPT pipe plug and installed a 1/8 90 deg nipple on the cold start injector location. However you want to do it is up to you.

If you have the IAC air go back to the TB you'll have to seal up the cold start injector location with a 1/8 NPT pipe plug.

The DIY autotune enclosure I bought fits perfectly where the A/C idle vacuum break mounts. Remove the vacuum break, and install the DIY enclosure to the bracket with two bolts. It bolts right on if you reverse the bracket.

I also had to modify my Jeep IAC motor a bit, apparently the DIY enclosure was fitted for a Jeep IAC but the seat inside was the GM size! Luckily the GM Pintle was the same thread and diameter as the Jeep one, just had to hog out the plastic on the end of the Jeep IAC so the bigger end of the GM pintle would screw all the way in. It works perfectly. Can't wait for the updated closed loop idle code to come out!

 

Use the vacuum tee that was previously used for the vacuum advance (since you won't be needing that anymore) to tap off the feed to the vacuum canister (if you have an A/C 280) to supply the MAP.

 

I mounted my TPS with shelf hangers. I filed down the TB nubs a bit and it fits tight and won't move ever. For a better look I'll eventually get a Q45 TPS, as it has the wider spacing.

 

Ok you should be done! You now have a Megasquirted 280z and it looks stock.

Cool.

 

Now it's time to program the MegasquirtII...Here's my advance and V/E tables and such to help you along.

 

I'm using 437cc.min ford TBI fuel injectors. Easily found in any junkyard, a hacksaw to the top of the TB and they're yours in 2 minutes. Need to find three cars, though. OH well. The bosch number for these blue (but probably the fuel will have bleached them green by now) top injectors is 250-180-400. Happy hunting!

 

Here's my specs.

 

Injector open time (ms) 1.0

Correction (ms/v) 0.20

PWM limit (remember you're still using the stock drop resistors) 100%

PWM time 25.4ms

Injector PWM 66ms

REQ Fuel- 7.0 (assuming 437cc injectors on stock motor)

Speed Density Algorithm

injections/cycle-2

stage: alternating

*Displacement in cubic inches for L28 is 168cid

 

Cranking RPM 300rpm

Trigger advance 48deg (I turned the crank to 75deg but I must have put the dizzy in a tooth off, ain't megasquirt cool?)

 

Cranking Pulsewidth

Prime pulse 1.0ms

Pulsewidth at:

-40F--16.0

160F--4.6

Flood clear threshold 70%

 

Warmup enrichment at coolant temp: (thank you mobythevan)

-40F 180%

-20F 150%

0F 140%

20F 135%

40F 130%

60F 125%

80F 118%

100F 110%

130F 103%

160F 100%

 

Stock 280z coolant temp sensor (not the gauge sensor) values

 

-40F 30-33000 ohms

80F 2000-2500ohms

160F 360 ohms

 

Afterstart enrichment

 

100% enrichment

250 cycles

 

I haven't yet set my acceleration values, still fine tuning the VE

 

Ignition Table still working on it but will get you driveable (lots of torque here, and even on crappy cali gas it only lightly pings when going uphill floored at 800rpm, and it goes up that hill like the devil is after it)

 

KPa| Advance in degrees (------denotes same value------)

100| 28 |28.6 | 29.5 | 30.5 |31.6 |32.6 |33----------------------33

95 | 27 | 27.7 |29.5 |30.9 |32.4 |33.8 |34.5-------------------34.5

85| 27 | 27.3 |30.5 |32.5 |34.4 |36-----------------------------36

80| 26 |26.7 |30.7 |32.5 |35 |37.1 |37.5--------------------37.5

70| 25 |26.2 |31.5 |34.5 |37.2 |39-----------------------------39

65| 24 | 24.5 |31 |35.5 |38.5 |40.5--------------------------40.5

60| 23 |23 |31.5 |37 |40 |41.7 | 42-----------------------42

50| 22 |22 |33 |38.9 |41.8 |43.5---------------------------43.5

45| 21 |21 |34.5 |40 |43 |44.7 |45-----------------------45

35| 21 |21 |36.5 |43 |46 |47.8 |48------------------------48

30| 21 |21 |38.1 |44.5 |47.2 |48.6----------------------------48.6

20| 21 |21 |40.7 |46 |49 |51------------------------------51

RPM 600|1100 |1600 |2100 |2700|3200|3800|4300|4800|5400|5900|6500

 

VE Table

KPa|%

100|92|92|92|92|91|90|89|95|99|96|96|98|

95 |90|91|88|90|87|87|88|94|97|96|96|98|

90 |89|88|84|86|87|86|88|93|95|96|96|96|

80 |83|84|82|85|87|86|88|92|93|96|96|96|

75 |75|77|76|81|84|88|89|92|92|96|96|96|

70 |71|72|73|79|81|86|87|93|92|97|97|97|

65 |70|69|71|77|79|81|84|89|84|89|90|90|

60 |67|68|69|74|75|75|80|85|80|83|83|83|

50 |65|66|66|73|73|76|79|83|79|82|82|82|

40 |64|64|64|68|73|74|73|81|74|82|82|82|

30 |64|64|65|71|74|71|72|76|74|82|82|82|

20 |63|65|65|70|75|69|69|73|73|80|81|81|

R x|5 |8 |11|14|20|26|31|37|43|49|54|60|

P 1

M 0

0

Ok that's it man my hands are sooooo tired. Hope this helps someone.

[twoeightythreez]

Oh yeah, forgot to explain the stock transistor ignition module. It's mounted on the right hand side kick panel, under a relay board which contains the horn relay, intermittent timer (wipers), primary ignition relay (there is another under the underhood relay cover) seatbelt timer, etc. Don't be fooled by the look of the wiper timer, it looks like the fuel pump relay in the service manual (that's supposed to be on the driver side dash) the actual fuel pump relay looks nothing like that at all. It actually looks like a regular relay. Oh one more thing on the factory FPR....it draws .2 amp, as in 200 milliamps. One hell of a relay! (If that sucker ever sticks man it must be REALLY bad...the click shakes the car)

Ok back to the task at hand. If using MS-II you don't need this thing. If using external ign. why not use this thing? It ran as good as any HEI I ever drove and it's already there! Looks pretty heavy duty too. Hey my Z ran near 14's with stock EFI and ignition. It can't be that bad. All you would need to run a V8 with it would be a dizzy with 8 poles in it. The red and green wires come from the distributor (variable reluctor)...I used my wires for MS stuff later.

The power wire is the L/W that comes from the Ign relay right above it.

the black wire is ground,

and the B/W wire is the negative coil input. It's about half the size of a megasquirt and looks a hell of a lot more durable than the HEI module. Just my two cents.

[BRAAP]

WOW!!!!! Thank you for the extremely thorough and DETIALED write up with step by step procedures that went into the custom portions of your project.

 

I think is one of the first MS-II N/A Z cars I’ve read about….

 

Good work…

[Nismo280zEd]

I just run the MSnSE on my 280z N/A just fuel only though. Should be pickn' up a dizzy thursday i believe

[proxlamus©]

awsome write up!

 

all ya need is pics and everything is 100% perfect!!

 

thanks!

[JustinOlson]

Great, Now I have a project for my stinking MS2 that I've never used.

 

Justin

[BRAAP]

Great' date=' Now I have a project for my stinking MS2 that I've never used.

 

Justin[/quote']

 

Justin,

If you decide not to use your MS-II, you wanna sell it or trade some work for it?

[twoeightythreez]

all ya need is pics and everything is 100% perfect!!

If anyone on this board lives near San Diego they're welcome to come over with thier camera and take some pics..my digital was stolen about 3 months ago ;(

[twoeightythreez]

I know I know, plenty o time to get another...but I'm spendin it all on the wi....I mean Z..I'm not married...to a human anyway...just to 1.5 tons of steel...and even that's cheating on my contracted one....95000 tons of US steel called the USS Nimitz! 8o)

[twoeightythreez]

Going turbo soon! Just have to get all the workups underways out of the way and I can continue wrenching on my Z!

[mobythevan]

link added to the must read threads, thanks for the writeup

[nullbound]

Awesome write-up! I would love to see pics whenever they're available, as I've been thinking of doing the same with my '78 280.

[twoeightythreez]

I just found out today that the ship has pushed the first workup underway back a few days. I'll get me a disposable digital and take some pics. Also will take some of my old dyno charts from Motorsport '05, it'll blow your mind.

I must have one L28 that's FEELIN' GOOD....oil burning and all put down 166whp and 179lb ft on the stock EFI thru the stock 3.54 R200.

The MS made it feel even TORQUIER if not any more powerful, I can't wait to see!

Then...turbo swap coming after the 1st workups underway (they'll give us a week or so inport so I'll be wrenchin after working hours!)

[twoeightythreez]

pics

underhood relays.zip