Few MS questions

[740 Turbo Brick]

I got my Speedometer to work today. All I did was change some connections at the ECU plug. I tapped into the TPS VREF wire, ran it to the Yellow wire at the ECU, which is power for VSS, Crank sensor and Cam sensor. Theoretically, you could do this way for the crank sensor too, but I ran it differently.

The yellow/white stripe wire in the harness is the signal from the VSS. This part may be different from others. I read the ECU pinouts for my year ECU, and there are two pins designated "To cruise control ECU". I figured this is where I would want to send the Speed signal. One of the wires was blank on my connector, but it did have another one. It was light green with a white stripe. I simply jumped the yellow/white wire to the light green/white wire to send the signal to the cluster. The last thing that had to be done, the sensor needs to be grounded. The ground wire is black with a green stripe. You can either run this wire to ground, or jump it to another ground (black) in the harness. It took about 10 mins and I had a fully functional speedo.

 

[740 Turbo Brick]

Anyone know how to get AC to work with the stock ECU removed? I tried mine out today, the Condeser fan comes on but I dont think the compressor clutch is engaging. There must be another signal wire going to it that the ECU controls? Should I just say #### it and take the whole 50lb system out?

 

[Fotowntalon]

Should I just say #### it and take the whole 50lb system out?

IMO yes, shaves weight, looks cleaner and makes things easier to work on

 

[VelocitàPaola]

Anyone know how to get AC to work with the stock ECU removed? I tried mine out today, the Condeser fan comes on but I dont think the compressor clutch is engaging. There must be another signal wire going to it that the ECU controls? Should I just say #### it and take the whole 50lb system out?

You have to ground the wire going from the stock PCM to the AC compressor clutch. A lot of people use a simple switch, but you must be careful because the compressor really shouldn't be activated when the engine is starting or at high speeds.

 

[740 Turbo Brick]

You have to ground the wire going from the stock PCM to the AC compressor clutch. A lot of people use a simple switch, but you must be careful because the compressor really shouldn't be activated when the engine is starting or at high speeds.

Thanks, I found the wire. I tested it out, and it seems the clutch still only operates when you push the AC button. I grounded the Green wire (to AC clutch relay) and the compressor didnt engage, turned AC on and it worked like normal, so Im assuming I can leave it grounded and use the AC like normal still.

If I decide its time to just do away with it Ill rip it out for the weight savings.

 

[Fotowntalon]

just a prewarning, if you decide to remove it and don't pull your engine, removing the ac lines seems like a lifetime job i am still finding damn ac when i do something random, its like Christmas to me "Ya more weight shaving!"

 

[ryanmeekins3]

I'm also about to buy a MegaSquirt Unit for my 420a turbo. I've been emailing SymTechLabs technical support about the Complete 420a/Neon MegaSquirt EMS kit lately. It seems if you want to have a stepper motor based IAC and Sequential Injection, you can't use the kit ECU. It only has 5 spare pins, sequential injection requires 3 pins and the stepper idle circuit requires 4 pins.

The SymTechLabs support is telling me I should buy a MS3 ECU with the MS3X Expansion board. Their MS3 board includes enough injector outputs and a cam sync input for sequential injection. However, you still have to purchase the option service for the stepper idle circuit.

I'm trying to buy the best MS ECU for a daily driven car, meaning I want the best idle possible. Is there anything besides sequential injection and the stepper idle circuit that I should add to the board for a daily driven car?

 

[96TurboGS]

I'm also about to buy a MegaSquirt Unit for my 420a turbo. I've.....

MS2 can support stepper and sequential injection but you would need to add a DB9, cam sync and injector driver board. So you might as well get the MS3 with its ability for more options and SD card for logging.

Is there anything besides sequential injection and the stepper idle circuit that I should add to the board for a daily driven car?

TachOut and something to switch the fan relays. Daily driving dependability will depend on how you have MS tuned.

 

[VelocitàPaola]

Is there anything besides sequential injection and the stepper idle circuit that I should add to the board for a daily driven car?

If you choose the MS3X card, you'll have the tachometer output and relay control circuits Rafiel mentioned built-in.

 

[ryanmeekins3]

So you might as well get the MS3 with its ability for more options and SD card for logging.

If you choose the MS3X card, you'll have the tachometer output and relay control circuits Rafiel mentioned built-in.

Yes, I'm getting the MS3 plus the MS3X expansion board for these 2 things plus many other features... launch control (GPI active low) and boost control. Will I also need an alternator voltage regulator or is one implemented?

 

[VelocitàPaola]

Yes, I'm getting the MS3 plus the MS3X expansion board for these 2 things plus many other features... launch control (GPI active low) and boost control. Will I also need an alternator voltage regulator or is one implemented?

That's separate.

 

[740 Turbo Brick]

Not sure if youre set on Sequential, but I had the same concerns before installing my MS. To be honest, I cant really tell a difference from when my car was on the stock ecu to now running non sequential injectors on my MSII standalone. I still daily drive my car (when its not being a typical DSM) and plan on doing so well into the high compression/low boost stage.

 

[ryanmeekins3]

Not sure if youre set on Sequential, but I had the same concerns before installing my MS. To be honest, I cant really tell a difference from when my car was on the stock ecu to now running non sequential injectors on my MSII standalone. I still daily drive my car (when its not being a typical DSM) and plan on doing so well into the high compression/low boost stage.

Do you have the stepper idle circuit? I just want my car to idle and drive like stock and read on this thread that sequential injectors would make a difference at idle. If it won't make a big difference, I'll be saving around $300 but won't have some other features of MS3 that I don't really need. I could still get the stepper idle circuit and launch control with the MS2 420a kit. I plan on running 15psi daily at 8:8:1 compression, if that makes a difference.

 

[740 Turbo Brick]

Do you have the stepper idle circuit? I just want my car to idle and drive like stock and read on this thread that sequential injectors would make a difference at idle. If it won't make a big difference, I'll be saving around $300 but won't have some other features of MS3 that I don't really need. I could still get the stepper idle circuit and launch control with the MS2 420a kit. I plan on running 15psi daily at 8:8:1 compression, if that makes a difference.

Yes I have stepper motor control, and its definately going to take you a while to know how to get your car to idle right. First you have to wire it up right, because there are 2 seperate coils inside the stepper motor and you cant really tell whats positive and negative just by looking. I might be able to post my wiring to help. On top of that, you need to fine tune the PID parameters in Tunerstudios. PID gains are Proportional, Integral, and Derivitive. Default values are 50 for P and I, and 0 for D. Its recommended you leave D at 0. You will have to play with P and I to get a good idle. P controls how sensitive the program is to changes in idle. This helps it catch sudden drops like when your fans turn on or another load is placed on the engine. I controls how quickly the RPMs settle to the target RPM you set. They are both numbers from 0-100, and both can cause idle hunting when improperly tuned.

 

[ryanmeekins3]

Yes I have stepper motor control, and its definately going to take you a while to know how to get your car to idle right. First you have to wire it up right, because there are 2 seperate coils inside the stepper motor and you cant really tell whats positive and negative just by looking. I might be able to post my wiring to help. On top of that, you need to fine tune the PID parameters in Tunerstudios. PID gains are Proportional, Integral, and Derivitive. Default values are 50 for P and I, and 0 for D. Its recommended you leave D at 0. You will have to play with P and I to get a good idle. P controls how sensitive the program is to changes in idle. This helps it catch sudden drops like when your fans turn on or another load is placed on the engine. I controls how quickly the RPMs settle to the target RPM you set. They are both numbers from 0-100, and both can cause idle hunting when improperly tuned.

Yes, the wiring diagram would much be appreciated if you decide to post one. And thanks for explaining the PID parameters; they make sense to me now. I've now decided to get the 420a MS2 kit with the stepper idle circuit and GPI active low (launch control). The leftover money can go to an Aeromotive AFPR.

 

[glowryder]

ODD.. i have MS2 i have seqential (peak and hold board), cam sync, tach output and cam sync module.. i have no other DBP or expansion boards...

 

[kongo]

Has anybody upgrade from 2 to 3?

 

[glowryder]

If your just starting and dont have MS, buy a MS3, but if you have MS2 and it works.. theres not to much of a reason to upgrade. imo..