Beginning Installation

[evil_datto]

Hi all.

I've finally decided to start ripping out the old stock stuff and get going with MS.

So I have a few questions before I head out to buy the rest of the stuff I'll need.

1 - For dropping resistors to use with the stock N/A injectors, what spec resistors

are best? Also, should I use 1 resistor per bank, or 1 resistor per injector?

2 - What size fuse do I need for the main power for MS?

3 - After seeing peoples problems with electrical noise, spikes etc. Should I use a

filter on the main power wire for MS? If so, what specs for the filter?

 

*Edit: I read that MSI is able to control electric fans, but the signal needs to be amplified

to even be able to trigger a relay. Does MSII still need to have it amplified?

 

Thanks, Scott.

Edited February 26, 2010 by evil_datto

[mobythevan]

Measure your NA injectors to see if they are high impedance or low impedance. If they are high impedance then you do not need the dropping resistors ( I thought from memory that they were high impedance but I could be wrong). If you need the resistors, it is one resistor per injector.

 

Look at the schematic for the relay board even if you are not using it. The schematic will show the main fuse value used for megasquirt.

 

I have not filtered the power to megasquirt on my installs. But read through the sticky on resets for general ideas on spark plugs, wires, grounding, etc.

 

Last, I believe the v3.0 pcb has an extra transistor or two that can be used for things like fan relay. The amplification stage (2222 transistor) is not an MSI vs MSII thing, it is more of a v2.2 pcb vs 3.0 pcb issue.

[evil_datto]

Thanks moby. Yeah my injectors are low impedance, I had the dropping resistor stock.

 

I've read a lot so far on the grounding and noise issues. The thing that made me consider filtering it

was from reading jacob80's posts showing his datalogs. The battery voltage looked really nasty until he filtered it

somehow.

 

Also, I'm using the 3.0 board, so hopefully it does have this amplification thing.

 

Thanks, Scott

[evil_datto]

So I'm taking out the stock ECU loom(81 turbo), and I'm wondering if you other guys had to cut the loom

to get it out or not? I'm having some trouble and it like the ECU end wont be able to fit thru the firewall hole..

and the other way seems just as difficult. I really don't wanna cut the loom..

 

Scott

[mobythevan]

I was putting everything in a 240 so I didn't encounter this issue. Maybe someone else will chime in.

[ThreeMoneyJ]

The loom doesn't need to be cut. You can feed it through the firewall from the engine side, but you will need to do it part by part so it fits as opposed to trying to shove the whole thing through at once.

[badjuju]

I just hacked it to little bits. :\ sorry dude

[zane9000]

I know this is an older post, but I thought I would throw in my 2 cents.

 

I have a V3 board and am controlling an electric fan via the FIdle port. It switches a relay without any problems. Also, I am not sure when this happened, but with the firmware updates within the last year or so pin 19 (I think) is now a dedicated sensor ground to help control noise.