Lambda after o2 install

[SamE30e]

Hey guys,

I got my M50 working and I've been driving it for a couple days with no o2. It worked pretty mint without it, just ran a bit rich.

I put a o2 bung in just after my long tube headers and installed a o2 sensor from a intrepid/ concord with the M50 plug spliced on.

The engine runs like a champ at WOT, but at partial throttle it runs like absolute shit unless it's under high load. At about below 10% throttle it sputter and jerks and at idle it hunts for a idle then eventually stalls.

I know the Lambda code is pretty bullshit and can be tons of things but does anyone have any idea?

Sam

[SamE30e]

Ok, so I put a actual M50 O2 in and it still runs like shit. At sleight throttle (below 10%) it sputters and runs like absolute shit. It idles, hunts, then keeps getting worse then dies.

I'm thinking ICV or vaccum leak.

Anyone?

I have a hollow cat/ no muffler and a 11lbs flywheel. Could that do anything? I'm putting muffler on soon.

[e30polak]

I felt no difference with mine one or off. Muffler would only effect decibel level and back pressure. Vacuum leak would cause issues with or without the O2. Could be the ICV or the MAF.

[SamE30e]

Hmmm, it runs mint with no o2 though which is fucked! Just runs rich.

[jrdeamicis]

Unplug the MAF and see if it helps the driveablilty.

Brake parts cleaner - use it to find a leak if you have one.

Check intake connection in the intake from the IAC to the intake.

[SamE30e]

This is driving me nuts.

[SamE30e]

I felt no difference with mine one or off. Muffler would only effect decibel level and back pressure. Vacuum leak would cause issues with or without the O2. Could be the ICV or the MAF.

The ICV works because it balances the idle with the o2 unplugged. Must be the MAF. I'll try and find another to test it.

[jrdeamicis]

Does it drive better with the MAF unplugged?

[SamE30e]

Dunno yet, haven't tried. I will tonight.

[loonibab325i]

maybe you need a tune?

[OrganicMechanic]

fuel and o2 relays have combined wiring for e36's. check the o2 relay. green wire should be sending 12v directly to the o2 heater. likewise, the red/white wires should be 12v. i would bet that you are not getting the 12v .......and it is causing the red/white wires to backfeed too. disconnect the green/violet wires at the c101 and pull power (via fusable link) from fuse 11 (fuel pump fuse) to green/violet (e36 harness wire) at c101. i capped off the green/violet wire on the e30 side.

car runs MUCH MUCH smoother as the o2 heater element is now working and the o2 sensor is getting the correct readings

[SamE30e]

So I should check for +12v at the o2 connector?

A guy on my street has a diagnostic reader for the M50, we ran it, and it wouldn't grab the codes. We're thinking it's his shitty program.

[OrganicMechanic]

what did you use for the wiring chart. I am going through the same thing. I wired in a relay to prevent the back feeding that some were talking of. I think the back feeding will send false voltages to sensors and cause weird issues. I just went through my harness and eliminated some of the wires I thought were correct. I am finding that some of the posted wiring charts are flawed.

[SamE30e]

Is the blue relay the o2 sensor relay?

Edit:

Ok so the o2 relay is the orange one, it wasn't getting 12v while the car was running or in the acc position, so I jumped the relay from the white one and it has 12v now.

I drove it around for a bit and the o2 code stayed on. I unplugged the battery it went away, I started it up and the check engine light flickered and then went off.
I drove it around again it was running alright till I drove it a bit hard and now its throwing the lambda code again but a soft code, like before, the light isn't on.

[OrganicMechanic]

I am fighting same thing.