Innovate wideband powered via fuel pump relay?

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molecular bob
Posts: 34
Joined: Wed Feb 22, 2012 3:50 am
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Innovate wideband powered via fuel pump relay?

Post by molecular bob »

Just going through the inherited chassis wiring on my car and discovered that the wideband is powered from the fuel pump relay rather than spliced into the ECU supply. Is this going to cause me any issues?
katana
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Re: Innovate wideband powered via fuel pump relay?

Post by katana »

Innovate recommend not allowing an unpowered sensor with running engine - the sensor heating does take 20 - 30 seconds so once the engine starts / fuel pump is powered the 'cold' sensor will be getting hit with cooler / wet exhaust which 'could' shorten the sensor life? I'd rather have a hot sensor and a non running engine ie. ECU / Ignition switched than the other way round!
molecular bob
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Joined: Wed Feb 22, 2012 3:50 am
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Re: Innovate wideband powered via fuel pump relay?

Post by molecular bob »

I think I understand the logic, but in practice ecu power on, fuel pump run and ignition are all at the same time (ish). My usual routine was fia on,key to position 1, wait~2 secs for fuel pump to give rail pressure (ecu triggered via pin 3), then start engine. Does anyone wait 30 seconds before cranking?
SMR
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Re: Innovate wideband powered via fuel pump relay?

Post by SMR »

Mine comes on with the ignition-on, and according to the logs, takes about 20 seconds to output a sensible signal back to the ECU. I've not had any issues with sensor life, so the 20 seconds running as the sensor heats up doesn't appear to have caused any issues. Having it come on with the fuel-pump relay does at least give it the quick 6 seconds of heat before the engine fires up so would seem to me to be better?
Alex DTA
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Re: Innovate wideband powered via fuel pump relay?

Post by Alex DTA »

Hot lambda sensors don't like cold water. Ideally they should not be powered unless the engine is running.
This is only an issue on cars where the ignition is turned on for a long time before starting the engine. In this case, the sensor will get heated up, but the moisture in the exhaust will be cold. If the cold moisture meets the hot sensor the ceramic can break, destroying the sensor.

Powering the Innovate from the fuel pump ensure the sensor cannot get heated if the ignition is on, but the engine is not running. This is the correct way to do it.
It also prevent battery drain, as the sensors draw a couple of amps while warming up.
katana
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Re: Innovate wideband powered via fuel pump relay?

Post by katana »

Just relating the Innovate instructions! Its ok having the moral high ground about how it 'should' be done except
when they ask 'did you follow the instructions' for your warranty claim!
molecular bob
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Re: Innovate wideband powered via fuel pump relay?

Post by molecular bob »

I have no chance of a claim anyway, there are 2 welded in bungs, one in number 4 primary which is too close to the head, and the other is in the collector but points downwards at about 8.00 O'clock, so which is "better" the one that will overheat the sensor or the one that will allow condensation to collect on the sensor. It only needs to work for mapping, so I may have to live with the condensation risk, there isn't enough room to use one of the extended bungs on the one that is too close.

The immobiliser cuts ecu power after 10 seconds if I don't go to start from position 1, so not too risky from that point of view.
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