95 XJR-Stores no codes-O2s inop-High HC and CO
#1
10-24-2009, 06:43 PM
Guest
Posts: n/a
95 XJR-Stores no codes-O2s inop-High HC and CO
I think I have the right section. I apologize if I don't, this is my first post here.
I am working on a bear of a car. It's a 95 XJR. What's even more hysterical is that I've got an identical problem car coming in on tuesday as well and a spare computer that was in a car that had the same issue. SO, that's 3 95 XJRs with the same problem.
Ok, I'm a licensed mechanic, worked in aftermarket a little and mostly with GM dealers and just started at a Jag shop. What I can't understand is what the heck they are doing with the O2 sensors on these cars. I've never seen a 5volt O2 circuit before. Do these sweep all the way from 0.??-4.898? I also read somewhere that the rich/lean conditions are inverse to the norm i.e. 0.1 would be rich and 4.89 would be lean but since the info on the internet is pretty sparse I can't confirm this.
What I've got is 0.000volts on the post cat O2s and 0.050-0.0125volts on the upstream O2s and they don't fluctuate at all. All four sensors are brand new and the ECU won't store codes at all. The rest of the system seems to check out. The ECU has good grounds. All the wires,terminals and connections check out from the O2 connectors to the ECU. This car has been molested by several mechanics over the past 2 years trying to sort this thing out so I thought I'd come here and see if I could connect with someone that I can ask direct questions about how these suckers operate. I've got some more testing to do and hopefully I'll feel a little more comfortable with Jags with your help. It would be great to contribute to this forum as well and since I work at an almost 100% Jaguar shop this place will likely come in very handy.
Thanks a bunch
Simon, Vancouver, BC
I am working on a bear of a car. It's a 95 XJR. What's even more hysterical is that I've got an identical problem car coming in on tuesday as well and a spare computer that was in a car that had the same issue. SO, that's 3 95 XJRs with the same problem.
Ok, I'm a licensed mechanic, worked in aftermarket a little and mostly with GM dealers and just started at a Jag shop. What I can't understand is what the heck they are doing with the O2 sensors on these cars. I've never seen a 5volt O2 circuit before. Do these sweep all the way from 0.??-4.898? I also read somewhere that the rich/lean conditions are inverse to the norm i.e. 0.1 would be rich and 4.89 would be lean but since the info on the internet is pretty sparse I can't confirm this.
What I've got is 0.000volts on the post cat O2s and 0.050-0.0125volts on the upstream O2s and they don't fluctuate at all. All four sensors are brand new and the ECU won't store codes at all. The rest of the system seems to check out. The ECU has good grounds. All the wires,terminals and connections check out from the O2 connectors to the ECU. This car has been molested by several mechanics over the past 2 years trying to sort this thing out so I thought I'd come here and see if I could connect with someone that I can ask direct questions about how these suckers operate. I've got some more testing to do and hopefully I'll feel a little more comfortable with Jags with your help. It would be great to contribute to this forum as well and since I work at an almost 100% Jaguar shop this place will likely come in very handy.
Thanks a bunch
Simon, Vancouver, BC
Last edited by satrianirocks; 10-24-2009 at 06:48 PM.
#4
10-28-2009, 09:09 AM
Guest
Posts: n/a
Car needs a computer as does the other 2 at the shop right now. I had the opportunity to swap computers from one car to another and the problems followed the computer. Regardless of the car it was in the live data was the same. One had ABSENT O2s but they all checked out for pwr/grnd and resistance. The other had O2s that wouldn't function.
I used to roll my eyes everytime I got a problem 95 GM car, now I will with these too.
I used to roll my eyes everytime I got a problem 95 GM car, now I will with these too.
