ridinwitcj73
ridinwitcj73 New Reader
1/8/15 4:26 p.m.

Like the title says I am doing my first MS project. It involves a 1973 CJ5, a AMC360, GM TBI, Innovate WB o2 controller, Walbro 392 fuel pump, a MS II and lots of learning. So if my questions sounds pretty newbieish its because I is one. I have had a blast figuring all this out but right now my main predicament is a minor questions on how I should ground my o2 controller. See below my original ramblings from another forum.

I am really having fun with this now as I am making progress! However as i was reading the manuals and startup guides i realized I had wired up a few things incorrectly. Mainly the fact that I did not put my distributor, injectors, o2 sensor and fuel pump on the same relay. I also realized that the relay should be grounded using the MSII pink fuel pump wire. I also had my wideband o2 (Innovate LC1) blue, and white wire grounded in the same place, where as per the manual the blue wire(for the heat shield on the o2 sensor itself) should be grounded to the engine with the other MS II grounds and the white wire which is the ground for the WB controller should be grounded through Megasquirt. I corrected this and DL the comm drivers for my serial adapter, uploaded the new firmware and I am now communicating with my MS II and have begun tuning. The problem is my wideband o2 sensor is not powering up and megasquirt is not detecting it. I know it powered up the way I had it wired before because the o2 sensors preheat melted the protective sleeve that was over the end of the o2 sensor. For the sake of clarity here is how i had it wired up before: Brown analog 2 wire going to the pink wire on the megasquirt, Blue and white wire grounded on the same lug to the body(which is hardmounted via welds to the frame). The red power wire going to a relay box with its own relay and a 20 amp fuse. I just had the yellow analog 1 wire and black test wire taped up.

Here is how I have it wired up now: Brown analog 2 wire going to the pink wire on the megasquirt. Blue wire being grounded to the engine with the other MS II grounds and the white wire is grounded through one of the MS II harness ground wires, The red power wire is wired to a circuit on the same relay that is being used for my distributor, injectors and fuel pump that is grounded using the MSII fuel pump wire. The o2 has its own 20 amp fused circuit. I tested this circuit with a test light and the first circuit was not putting out any power, which was odd because it had worked before when i had the MS II wired to it in the first wiring configuration I used. I checked the fuse on this circuit and it was good so I used another circuit on the and I tested it with a light and it is getting power now but still the controller is not powering up from what I can tell and the MS II is not detecting any input.. The only discretion I have found is that the LC1 start up guide suggest that both the blue and white wire be grounded in the same place on the same lug with no other lugs connected like i had before......... Any thing you all see that i am missing? Anymore info I can provide that would help? The relay and circuit block I am using for the distributor, fuel pump, injectors, and o2 sensor is a painless 7 circuit setup like this:

bigdaddylee82
bigdaddylee82 Dork
1/8/15 6:41 p.m.

Pink wire on the MSII is the O2 input I assume?

You've probably already read this: http://www.diyautotune.com/faq/faq.htm#LC1wiring

I need you to figure all this out so I know who to go to when I have questions.

ridinwitcj73
ridinwitcj73 New Reader
1/8/15 8:41 p.m.
bigdaddylee82 wrote: Pink wire on the MSII is the O2 input I assume? You've probably already read this: http://www.diyautotune.com/faq/faq.htm#LC1wiring I need you to figure all this out so I know who to go to when I have questions.

Hi Lee, yes you are correct about the pink wire. Thanks for that link, I have not read that exact page before but similar. Where I got the idea to wire it to the same relay as my fuel pump was the wiring diagram in MS2/V30 Hardware Manualon page 14. But if you read on in section 3.4.6 it also mentions to follow the directions of you controller. It was brought to my attention on the ms extra forum that the fuel pump relay using the purple fuel pump wire from the MS II to ground the relay, is only activated during the prime or when cranking. I have to think on that alittle more but it is plausible that I need to connect 12V wire for my O2 controler to a different relay that has continuous power when the key switch is on. I will get it figured out Lee! Slow but sure.

ridinwitcj73
ridinwitcj73 New Reader
1/8/15 9:18 p.m.

Ahhhaa! A closer look at page 14 reveals that the NARRROW band o2 sensor is wired with the fuel pump relay not the wideband o2.

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