rusnak

Here's a picture of the lambda sensor. I ended up gluing the old connector back with JB Weld. I thought and thought about it, and I decided that it would be best to use the old rubber boot to keep the pins connected due to heat in the engine compartment, and the fact that the original wire was unbroken.

Ed Hughes

When I built my airplane, solder was considered a no-no due to vibration being its enemy. Same goes for boats.

rusnak

Interesting that you bring this up. I was watching a guy on a boat TV program saying that he uses only crimp on connectors. I don't remember the name of the show.

james brown

DO NOT solder a O2 sensor wire! the wire needs to absorb O2 through the insolation into the wire for the sensor to work properly. use the crimp-on splice only l don't have a link to corabrirate this info so do a web search on this topic or read the instructions that come with a new universal O2 sensor.
So, i'm thinking, the reason the wire and plug fail so often and have not been re designed is that this part (the O2 sensor) is part of the federal pollution system and the feds are the ones that mandate how these parts are made.
so if it ant broke (so to say) why fix it?

rusnak

My picture doesn't show my solution to the broken O2 connector problem: a cut down the side of the rubber boot. I keep the connector on with a zip tie around the OD of the rubber boot, closing the cut and tightenting the boot around the connector.

I took it for a drive last night, first time ever with the LM-1. In closed loop, the dme kept the afr between .99 lambda and 1.01. It was fluctuating quickly, but working with computer like precision. I almost want to go back in for a smog check now, but I have a new AFM arriving via UPS on Friday.

scottb

I've heard people say this (there's a long thread on Pelican about this issue), but I soldered my connections and the car is running fine. It's passed smog at least two or three times since I changed the O2 sensor.

YMMV.

rusnak

I'll confess my ignorance of how an O2 sensor does what it does. But the Innovate Motorsports instructions say that theirs, a wideband O2 sensor, samples ambient air through the back of the sensor, which is why the sensor needs to be mounted in an exhaust bung, and can't work if the whole thing is fed into the tailpipe, wires and all.

rberry951

The innovate LM-1 I had came with an tailpipe sniffer, essentially a clamp that attached to the end of the exhaust, and teh O2 sensor attached to that in a pitot tube of sorts. Worked well, cept for the wires slapping against the back of the car at high speeds...

irobertson

Solder vs. Crimp

I would do the crimp connection almost every time.

When you solder a wire (particularly copper) the heat of the soldering process takes the temper out of the wire near the joint. Any flex due to vibration from that point on is not distributed evenly along the wire. It is concentrated in the area where the wire is softer, right at the solder joint.
Almost allthe failed solder joints I have seen happen this way.
Solder joints also have a higher electrical resistance than crimp joints. (solder not being that good a conductor)
They are also more prone to oxidization of the joint over time.

The trick with crimp joints is to have the right tool and do the joint properly, and to use a crimp of the proper size for the wire guage.
Not enough force leaves a loose joint, which can worsen over time as the strands in the wire settle.
Too much force can crush and partially cut the wire.
Get a good crimp tool from an electronics or electrical supply store.
Not one of those bargian tools that comes with a pack of 50 crimp connectors of various colors.

A properly done crimp joint is air tight where the two metals come into contact, and less prone to oxidization.

Then there's the matter of heat.
Oxidization occurs more quickly when things are hot.
If things are hot enough, a solder connection can get soft, or even melt, then reform when cooled.
This results in a crystalized (cold solder) connection. Bad news.

Hope this helps.

cheers

Steve Weiner-Rennsport Systems

Well said, Ian,...

With good quality crimp connectors (such as AMP) and professional-grade tooling, one makes reliable electrical connections that will not give trouble.

Harbor Freight & Radio Shack stuff do not qualify,...