o2 sensor delayed power up?

[jpryorx2]

how is everyone wiring there 02 sensors? im in the process of putting my system together and bought the 14point 7 spartan2 and the directions say "Do not install the Lambda Sensor in such a manner that the unit is powered before your engine is running. An engine start can
move condensation in your exhaust system to the sensor, if the sensor is already heated this can cause thermal shock and cause
the ceramic internals inside the sensor to crack and deform."
the only way i've found to delay it powering on is a relay from the uk that with shipping cost 60 buck? https://www.12voltplanet.co.uk/adjustab ... v-10a.html
is there a cheaper way that would still be durable enough to be bouncing around in a sandrail or are you guys just taking the chance and powering it up at start up?
thanks
jason

[Bruce.m]

The problem is if you power up the sensor it will activate the heater inside since it’s cold & once hot it will be killed by a splash of water. You could take a chance & power it from the switched power supply (coil power) but if you leave the ignition circuit powered without starting up then there is a risk.

You could use a normally closed relay and link its earth to the stock oil pressure sensor (power to coil feed). That way the o2 sensor would not power up until the engine has started & has oil pressure.

Bit late, but I ordered a wideband controller which has a switchable setting to use the OEM warmup feature. That stops the sensor heater until the exhaust air heats up.

[jpryorx2]

that would work only problem i could see is i have the tdi starter on it and it cranks so fast it builds pressure almost instantly. its a fresh build so everything is nice and tight i started breaking it in with a set of kadron but it ran to lean and wasn't wasting money on jets just or break in

jason

[Bruce.m]

I’d don’t think the sensor will get hot enough in the time it takes to start the engine. You could test the wideband & see how long it takes from a cold power up to get a reading. That’s how long it takes to heat up using the internal heater.

[Steve Arndt]

I like it powered it powered with key on. Then I can tune my cold starts.

[jpryorx2]

ok i just got worried after reading the directions again. im running a trimill so didn't have the option of mounting the sensor in the top of the pipe like they say to and i know i've seen water spraying out of the exhaust in the past when i fire it up. right now i'm gathering more parts for attempt 2 on the intake as soon as the snow stops.

jason

[jpryorx2]

been thinking about it as i'm laying out my wiring in a water proof box and had the idea just wiring it to the accessory position of my ignition.that way the o2 wont have power when the key is in the start position. also since it draws less then 5 amps i don't see a reason to put a relay in either. what do you guys think?
jason

[jpryorx2]

ok next question is there any reason why i can't supply the power to my coils and injectors thru the same 30amp relay?

[Steve Arndt]

I have a 70 amp relay that powers my coils, injectors, O2, etc. on my extra fuse panel in the rear.

[jpryorx2]

ok so right now im thinking 1 30 amp relay for the fuel pump and 1 or the coils&injectors the relays will have constant fused power then a switched fused power for the ecu and then a fused wire off the acc terminal of the ignition for the wideband controller. i'm trying to make it all fit in a 7x11 water proof box. so kinda laying it all out before i drill any holes to mount anything i don't have a garage so at least i can get this part it done while waiting for spring