Jump to content

O2 Sensor Issues - lsu4.9


Wuppet

Recommended Posts

Hoping for assistance.

 

I have always had trouble with sensors failing, typically just dead no readings, put a new one in and off she goes again.  at a guess 7-8 in last few years on a street car that is driven very little, although I play with combos a lot.

Thunder g4+ ecu

Latest setup is with 6/71 on the 496 - EFI through hat

1 of the sensors was not reporting so I replaced both with "cheapies" after deciding that the genuine (all previous) dont seem great - immediately nothing from both - I put the good one back in and still nothing.

After some research here a suggestion was to add all the error reporting parameters to try and determine what is happening.

Can see that I have probably been throwing good sensors in the bin, just cant see why.

I have again today checked the wiring on both sensors - each wire back to ecu plug (and to ground and each other pin to ensure no short somewhere) and the power is supplied via fused 30amp relay which is switched at ecu power on - checked that it is constant 12v

Got me stuffed!

I have attached map and log file whilst it had 1 dud sensor,another log is after replacing both, third is after putting "known good one" back in - in chronological order

Is the "pulsing on" and off (see lambda tab and log files) an indication that they are damaged?

Hoping you folks can have a look at the logs etc and offer some ideas.

 

Link to comment
Share on other sites

I see that "Run when stalled" is disabled, which was my first thought - I've seen many sensors "killed" by sitting with ignition turned on, but not starting the engine, heating up the sensor, then when you finally start the engine, you throw cold, potentially damp air onto a very hot thin ceramic plate, shattering it.

 

How are the sensors themselves installed? What location, what orientation?

Link to comment
Share on other sites

36 minutes ago, Confused said:

I see that "Run when stalled" is disabled, which was my first thought - I've seen many sensors "killed" by sitting with ignition turned on, but not starting the engine, heating up the sensor, then when you finally start the engine, you throw cold, potentially damp air onto a very hot thin ceramic plate, shattering it.

 

How are the sensors themselves installed? What location, what orientation?

Will check that, these logs were from cold start, pretty sure that the ecu delays heating sensor until engine running

sensors installed just after header collector facing around 2 & 10 oclock downwards

Link to comment
Share on other sites

  • 3 weeks later...

Some feedback - I believe my issue was caused by noise on power line,  I was drawing from same busbar as among other things the fuel pump.

I have now run power direct from battery via relay and some of the sensors that previously would not reach temp are working,  whilst some are not I have had the same two that previously didn't work in it for a reasonable number of road tests and shed tests without failure

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...