Lambda after o2 install

[SamE30e]

I used this
If you jump it to green and violet on the fuel pump relay, the fuel pump stays on constantly.

[OrganicMechanic]

I keep finding people talking about back feeding on th O2 circuit, so I isolated the 2 wires by use of relay. Also poured over hours of notes and research recheck adapter harness. I think I have solved it put everything backin order. I drive it last night and it is just raping the pavment...went to my pratice lot and ripped a good 15 min session and just was flawless. Today I pull out of garage and and get on Highway and feels like fuel cut at 4500ish rpm. WTF what am I missing.

1-replaced HFM
2-replaced crank reference sensor
3-confimed harness
4-replaced fuel filter

need to check--
1-Cam sensor? quick ohms on this?
2-ohm out the O2 harness to the DME pins


got to be something easy. Ran so good when I first started and drove the first 200 miles.

what is your methodology of diagnosis?

I have a 525i service manual and need to look up cam reference sensor, I am pulling at straws at this point.

[SamE30e]

I'm going to put a switched 12v to my o2 heater, and then clean my maf and see how that works out.

[SamE30e]

Cleaned the maf it ran alright for a couple minutes. Drove it a bit agressivly and then it threw a Lambda code again.

[OrganicMechanic]

Hey,

What's this 13 to 13 connection business?

Sam

there is some back-feeding to the O2 from a direct 13-13 connection. I used a relay to power the e36 13 pin and used the e30 pin 13 to trigger the relay. I seem to have solved issue thus far. I can say to try it and see if it helps you. I have been digging thru the archives trying to find where the problem is but there is no definitive response.

are you running a h pipe or a x pipe?

fuel filter? kinked line? Dirty injectors? weak pump?---

this just came to my head--back in the good ol days of 500+ hp DSMs there was a guide on free Hp. One of the things in this guide was to relay your fuel pump closer to the pump and directly to the battery. -- Now I don`t know if you have updated your pump to a 255lph yet so I am assuming not. But if your pump is not able to keep up with demand at WOT it will cause a lean condition at higher RPMs.

A thing to think about also is --if your engine was sitting for a long period before installing. You might just have a slight varnish issue in fuel system, google DIY injector cleaning.


pulled wires in harness could be also making intermittent contact. Runs great one day and the following day hesitates at 4800WOT, but if I ease up there it goes but lack of power. Today --raping the pavement again, feels unbeatable.

I am almost thinking that the DME just needs to set it long term trims and then things will be fine.

[OrganicMechanic]

So you're saying just cut the 13-13 connection and add in a relay powered by the fuel pump switched 12v?

no--

cut 13-13
on the relay you will see these numbers
connect--

-- relay-- wire--
30-postitive key on(power)
85-ground
86-pin 13 from e30
87-pin 13 e36

[SamE30e]

I think I solved it. The relay wasn't turning on for the heater so I jumped the switched 12v from the main relay to the o2 sensor relay. That with a combination of a shitty seal off my headers causes the problem. So far no check engine light.

[1991 e30 bmw 318is]

I think I solved it. The relay wasn't turning on for the heater so I jumped the switched 12v from the main relay to the o2 sensor relay. That with a combination of a shitty seal off my headers causes the problem. So far no check engine light.

any pics of the wiring? i think ill be doing the same thing..

[Lof8]

bumpin this thread up guys. My cars running like crap and I'm getting o2 sensor heating codes. I don't totally understand what is being described here- o2 not heating up or interference or both? - please elaborate for a wiring newbie.

Where is the o2 relay located? in the underhood fusebox? Which one is it?

I didn't build my adapter, so my knowlege here is limited.

Hopefully I can get this thing running well soon.
thanks

[omar85]

Does it drive better with the MAF unplugged?

why would it?