Some newbie quesions about assembly

[orava]

I'm a little confused about a couple of things with assembly and I was hoping someone here could help me out.

1) On the DB37 pins 1,2, 7-19 are all interchangeable grounds. It says it's important to ground the sensors to the Megasquirt controller and then ground the Megasquirt controller to the engine. I assume I would use one of these pins to connect to the engine? The reason I ask is that that manual has pins 15-19 as "power ground," but it seems like one good grounding wire to the engine would do the same thing. I am I missing something here?

2) If I want to use 4 of those spare ground pins to run LSX coils, do I run a wire from the new chips in the proto area right to the where the DB37 pin is installed on the board or do I have to remove that pin from the board and then run a jumper to it. (Kind of like when you do the low-Z injector mod.)

3) It says to run shielded coaxial cable to the VR sensor with the ground wire attached to the metal shielding on the outside. I know this might sound stupid, but can I run television coaxial cable to do this?

4) I'm still thinking about using a hall sensor. Is there a good car to take these from in the junkyard? If not, would this one work?

http://www.mouser.com/ProductDetail/Lit ... oCcSLw_wcB

Sorry if these are really basic questions. I'm just trying to learn how to do this.

Thanks

[Matt Cramer]

I'm a little confused about a couple of things with assembly and I was hoping someone here could help me out.

1) On the DB37 pins 1,2, 7-19 are all interchangeable grounds. It says it's important to ground the sensors to the Megasquirt controller and then ground the Megasquirt controller to the engine. I assume I would use one of these pins to connect to the engine? The reason I ask is that that manual has pins 15-19 as "power ground," but it seems like one good grounding wire to the engine would do the same thing. I am I missing something here?

You will want to run 5 ground wires to your main ground point. It's best to put this on the battery, but the engine or cylinder head will also work. In my experience, "good chassis ground" is an oxymoron.

Do not attempt to use the MS grounding wires to tie the engine block grounds to the battery.

2) If I want to use 4 of those spare ground pins to run LSX coils, do I run a wire from the new chips in the proto area right to the where the DB37 pin is installed on the board or do I have to remove that pin from the board and then run a jumper to it. (Kind of like when you do the low-Z injector mod.)

You cannot use the ground pins as spare outputs.

3) It says to run shielded coaxial cable to the VR sensor with the ground wire attached to the metal shielding on the outside. I know this might sound stupid, but can I run television coaxial cable to do this?

If the coax cable is stranded core and rated for engine compartment temperatures. Do not use solid core or low temperature wire.

4) I'm still thinking about using a hall sensor. Is there a good car to take these from in the junkyard? If not, would this one work?

http://www.mouser.com/ProductDetail/Lit ... oCcSLw_wcB

Sorry if these are really basic questions. I'm just trying to learn how to do this.

Thanks

That sensor will work.

[DaveEFI]

I'm a little confused about a couple of things with assembly and I was hoping someone here could help me out.


3) It says to run shielded coaxial cable to the VR sensor with the ground wire attached to the metal shielding on the outside. I know this might sound stupid, but can I run television coaxial cable to do this?



Sorry if these are really basic questions. I'm just trying to learn how to do this.

Thanks

Any co-ax cable is a single central wire with a screen round it. All VR sensors etc require a twin screened cable, with the screen only connected at one end. TV aerial cable is also usually solid core - it is not expected to be moved or bent much.

For a VR sensor, or any other that requires a twin screened cable, I use a good quality balanced microphone cable, which is usually easy to get. Sometimes known as XLR cable.

[orava]

Thanks for the answers, I really appreciate it. I have bigger problems now, though, and should probably start a new thread.