Normal readings or Wideband

**Turk** · 5-4-09, 22:06

Ok help me figure out if my wideband is working/wired up correctly.

THis is all from morning start. Keep in mind, bodgy tune.
When there is power to the controller, gauge reads 7.4.
Turn car on, gauge warms up then shows about 20.#etc while car warms up.
Once it starts getting pretty warm (temp needle moving) starts dropping from 20 to about 15 gradually till it hovers around 14.5-15.
Once fans kick on drops to about 12 for about 20 seconds till it comes back up to 14.5ish again.
It will fluctuate alot between 14.5-15ish at idle, everynow and then flickers to high 13 low 16. If I even touch the tune to lean/richent it by 1 or 2% it will go to about 17 at highest to 12 at lowest. I do have a pretty [shizzle]ty idle though from way back in the day even on stock ECU.

Turn the car off (leave it on reds) and gauge will stay at whatever was last reading for a while before eventually I cant remember it either leans out or richens up to full rich again.

Is this normal operation, going so lean on warmup doesnt seem right? And it shouldnt fluctuate that much right?

I have every ground point of the gauge and wideband to one lug then bolted to chassis that I have sand papered back. THe Megasquirt ground is on the same bolt but a different lug.

Oh and I am still getting inteference on my radio on certain stations. The inteference goes up as my revs go up. It sux. No sound system/dodgy amplifier either.

**Turk** · 5-5-09, 19:53

Can I just get a yes that is normal tune away or no something is wrong fix it first?

**Chefsp0t** · 5-5-09, 20:25

Those numbers all seem okay. Are you using any warmup enrichment or anything? You could do that and your numbers would stay more even.

**Turk** · 5-5-09, 21:21

Sweet, I just wanted to make sure that it was wired up properly before I tuned and blew it up. The warmup enrichment's are whatever came on the basemap, I haven't got that far yet. Yer its been a year, I have been lazy.

**Zach** · 5-6-09, 10:50

Turk, I get the same thing at idle...but I've leaned my out a bit...I get into the mid 17's...and it bounces back down to the low 15's...it's pretty cyclical and almost predictable; rich/lean/rich/lean/rich/lean, etc. lol

**RbluEMx6** · 5-6-09, 13:27

On a cold start, this is how mine goes:

Key on, gauge reads around 20+-

Turn on engine and gauge drops to about 10
This is because I have it running rich on cold start.

once it warms up the gauge will be around 12-13 afr's on idle. and sometimes fluctuate from 12-18, in respect to rpms as is drops up and down between 900 and 1100 rpms

Now it sounds as if you have an LC-1, if so there are two wires that need to ground to the same reference point but separately. And power needs to be available during cranking too. Some power connections don't get power during cranking.

As for interference, do you have coil packs? What Kind of plug wires are you using? When I used EDIS coil packs it came with a little radio suppression device that eliminated most interference. unshielded trigger wire and alternators can cause interference too.

**Turk** · 5-6-09, 23:51

Mine should go rich on start as well but instead it reads lean. So that is a problem ok, maybe just tune, I will have a look.

Idle once it warms up sounds the same as mine, least that is ok.

I do have an LC-1, what do you mean same point but separately? I read that bit in the instructions and that had me confused for months honestly. I figured that they want the 2 grounds to the same point but not both wires spliced to one then connected, but that they both meet on the same lug and get grounded to the frame on the same bolt. Tell me if im wrong here.

I use disty still, and using MSD leads that are fairly new. Problem was still there with the old leads as well. I didnt think I would need a suppression device as that would just be a bandaid for a problem that I created. I know there is something wrong somewhere. I dont really care about the radio but interference there could mean interference elsewhere as well.

**RbluEMx6** · 5-7-09, 14:23

The LC-1 has two grounds, the white and blue wire. They are two different grounds(heater ground, system ground) that need to meet at the same grounding surface. In the manual it says that you can solder both to the same lug and connect to a single point.

However if your sharing the same bolt with multiple lugs, then that can cause unwanted signal noise. At that point you should split them but keep them grounded to the same metal surface close to each other. As well as the ground for the analog gauge.

So if your LC-1 heater and system ground are connected and grounded to a single point, your gauge grounded to the same surface but separately, and you have constant power during cranking, your wiring should be fine.

Also, are you checking the LC-1 readings in logworks? Its a much accurate reading and can tell you if you are getting any error codes. My gauge didn't show me that I had low voltage issues. In logworks I was able to see the error code telling me that I need more voltage(better 12v connection) so that LC-1 can function better. I still need to fix that problem and see how the wideband reads afterward.

**Turk** · 5-8-09, 23:54

I lost the LC-1 to PC cable some time ago. WIll have to go to a computer shop and look for another one.

I have my wiring wrong then if what you explained is the case. I understand now though and can fix it.

I dont have constant power while cranking though. I dont know of any source that can do that except for the Megsquirts/standard ECU power source. Would I be ok to power the LC-1 and the gauge off that as well? Or is that too much to ask from the one power source?

**Chefsp0t** · 5-9-09, 0:00

My Lc1 doesn't have constant power at cranking either. It resets every time I turn the key.

I don't think I would draw power from the MS power source though Turk.

**Turk** · 5-9-09, 8:10

I didnt think so either.

Also, at the moment a Megasquirt ground is going to the same lug as the LC-1 heater and system ground as well. Should that be seperate too?