Lambda reading 1.75 always!

[Sean]

You won't necessarily see evidence of air leaks IN to the exhaust. Have you any slip joints in the system that can suck in air with the engine running? One other thought, you do have the correct pinouts for the 017 025 sensor? I guess you have the normal automotive lsu 4.9 plug?

http://www.bosch-motorsport.com/pdf/sen ... /LSU49.pdf

[Martin]

Make sure you have Ip and Vs not swapped around. It will read lean if this is done but it still air calibrates

[stevesingo]

Thanks for the pointer, but I have already seen this. I inserted the sensor in to the end of a blow lamp, taped up the gaps, but with a pin hole for the pressure to escape. Turned on the gas, La1 = 1.05, regardless of sealing the holes or not. As for back pressure, I have two in line, straight through silencers and the quantity of the gas emitting from the tail pipes at idle seems normal. The exhaust would have to be very restrictive to have an effect at idle, or any no load engine speed.

Steve

Do you have a high back pressure?

Try this page for some basic lean and rich testing: http://wbo2.com/lsu/position.htm
That website has a good amount of info on wideband sensors.
The different sensors (4.0/4.2/4.9) have different wire arrangements and different plugs. There are now 6 cables in some "5-wire" sensors. The 6th is an Rcal wire with a laser trimmed resistor for calibration. Check the site above as it has the connectors and wiring as well.

[stevesingo]

Thanks,

I suppose I can test that by putting a rag over the exhaust at idle, increasing the pressure in the pipes. This should create positive pressure in the exhaust end expel any drawn in air...should go rich.

I'll give it a go.

Steve

You won't necessarily see evidence of air leaks IN to the exhaust. Have you any slip joints in the system that can suck in air with the engine running? One other thought, you do have the correct pinouts for the 017 025 sensor? I guess you have the normal automotive lsu 4.9 plug?

http://www.bosch-motorsport.com/pdf/sen ... /LSU49.pdf

[stevesingo]

Make sure you have Ip and Vs not swapped around. It will read lean if this is done but it still air calibrates

Thanks

I have checked this against (admittedly) against my in/output spreadsheet. There may be a mistake on the spreadsheet, so I'll cross check.

If these are wired incorrectly, does it cause damage.

Steve

[stevesingo]

Cross checked my in/output spread sheet to the drawing and found I had made a typo, in that I had La1 Ip and Vs the wrong way around.

Swapped the pins in the sensor connector and it now works fine. It also works with my original sensors Bosch 0 258 017 066/67.

Thanks for those who contributed.

Steve

[Martin]

Glad you got it sorted.....

Dont think it damages anyting, its happened to me before,ECU still going
Maybe someone at Motec could advise.