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Old 02-16-2013, 03:20 PM   #1
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Default Can raw fuel ruin a Bosch LSU 4.2?

I've taken the LC-1 from my 'old' MK1 MX5 and put it in my new MK2.5.

It's not been used in 12 months, and the last time it was used it was working, however the engine died in the MK1 from a valve spring snapping.

THis meant zero compression on Cyl1 and was driven as such for a mile or so until it was safe to stop.

The engine is now fine lukily replacing the spring was all that was required, but during diagnosis the engine was started multiple times.

Now the LC-1 is in my MK2.5 it just won't give a realistic reading, there are no error codes, and it is 100% wired in properly.

When you calibrate in free air it's fine, reads 20:1+ etc, but as soon as you put it in an exhaust stream the AFR's it's reporting are bonkers 30-40:1

This is from Logworks btw, so there's no weird voltage offset going on.

The only thing I can think it is, is the sensor is borked from being dowsed in unburnt fuel, but can anyone confirm my theory before I stump up money for a new sensor?

Alternatively can it it cleaned/resurrected somehow?

TL;DR - LC-1 sensor gives funny readings after being dowsed in unburnt fuel, wants to know if it's now dead.

Many thanks!
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Old 02-17-2013, 03:38 PM   #2
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Even if you could get it clean to where it gave some kind of "reasonable" figure, would you really trust it?
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Old 02-17-2013, 04:15 PM   #3
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Open it up in LM programmer. I bet that it got confused as to what gas stoich was, which does happen on LC1s. Because it cannot read that lean in gaslone afrs but if the stoich value got corrupted then who knows.
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Old 02-17-2013, 05:18 PM   #4
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I've tried resetting to defaults and messing with LM programmer, makes no difference.

I've tried the 1.2 beta firmware and downgraded to the original v1, no difference.

I guess I'll just have to buy a new sensor, what worries me is the controllers borked and I'll be wasting my money?
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Old 02-17-2013, 05:35 PM   #5
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I'd say to just call innovate but I dont know how expensive that would be calling from europe.
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Old 02-24-2013, 01:57 PM   #6
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I emailed Innovate in the end, they replied but couldn't give an answer either way, so I took a punt on a new sensor.

Fixed it, so the answer to my question, is.... yes it does!
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Old 02-27-2013, 09:55 AM   #7
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A hot sensor can be thermal shocked and fail when splashed by a liquid. This is why you don't want to leave your ignition switch on for an extended period of time before starting the car, especially on a cold start.
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