Talk Morgan Forums Community Welcome Forum new member with GEMS O2 question

Hello all,

I was recently given a link to this forum and have lurking about the edges waiting for a reason to join which has now come up

I installed a Tornado chip in my '98 +8, GEMS NAS car last April and was preparing the car for a followup dyno run as I have over 3k on the new chip when I noticed via my Nano printouts that the pre-cat O2 sensor on bank 1, odds, read 6.17 while the bank 2, evens, read 0.37. I am not sure what the numbers mean but suspect I have an O2 problem. The car seems to run just fine but would like the O2 question resolved before putting it on a dyno.

Thanks all and looking forward to learning more from the group. I live in Portland, Oregon, and am a bit on my own with this car which I have had for just under 3 years. My first Morgan.

Thanks again, Skip # 12034

Hi Folks,

I just talked with a fellow that understands modern ECU EFI systems and I appear to have posted my question to quickly. I guess O2 sensor activity needs to be looked at over time rather than for an instant. I also had a series of Fueling readings over about 1 minute and see that both sensors cycle up and down from about 0.22 to about 6. I would have a problem if one of the sensors did not change at all.

Now it is time for a G&T.

bye, skip

Good Morning Skip, and welcome to TalkMorgan

There is nothing nicer than resolving an issue yourself keep posting, others could always have the same issues.

Skip,

Normally if you have an 02 Sensor problem it would show on the MIL light, however I have a sneaking suspicion that the MIL light is disabled on the Tornado chip (anyone know?) However if you have a problem, then the engine would not be running correctly.

As you seem to have a diagnostic unit can you check the operational mode which should be running closed? if so the 4 sensors and the heaters have passed all the diagnsotic checks.

Alas here the sum of my knowledge ends, so not too helpful I'm afraid.


If you have not seen it, I would browse through David Poole's Truly Excellent Gems Guide

Brian

Brian,

I have a copy of Poole's opus on both of my computers and am in and out of it frequently. It has been a big help. As I noted in my second post, I over-reacted to a slice of information I from the Nano. It did occur to me that the MIL light was not on and the car otherwise was running well but still I was alarmed. Once a more knowledgeable individual explained to me how the O2 sensor loop works ie the fine points of how it cycles. With that understanding and a print out of the raw data, not easy to read, it was obvious that I had no problem.

I am pretty sure that the Tornado chip is not disabled.

Skip