Hi

I had a blowing downpipe/Cat on my 2000 Xj8 3.2. Other than that, the car was running fine.

I have bought a replacment, swapped over the two O2 sensors (upper and lower). I then fitted the cat back and replaced the inlet air which I had removed to get access to remove the cat. I've not knowingly touched or disconnected anything else.

The car will not now start. It turns over fine and I can smell fuel but the only troubleshooting I have done so far is to check the fuel cut-off switch and had a look to check whether the O2 sensors are connected. I've had a quick look at the ODB readings and can see only one line which might tell me something:

ECU#1 open loop due to insufficent engine temperature
ECU#2 open loop due to insufficent engine temperature

Before I start going down a troubleshooting journey, does anything obvious spring to mind from any of you?

Thanks

Mark

 

No idea on that...I'd try a system reset myself....you know, battery disconnect, touch negative to positive cables. I generally put an alligator clip lead between the two for a minute or two...weird problem

 

Check the circuit to the fuel pump. Use a smart phone with the Torque app to connect to the vehicle's PCM via the OBD port with a Bluetooth interface to read fuel pressure. There should be around 3 bar (300 kPa) of pressure when the ignition is switched on prior to engaging the starter.

 

Hey NBCat, I used to visit Newport Beach when I attended CalPoly. I would bet it has changed
a bit since then. That information regarding the start pressure before engaging the starter is new
to me. Thanks for the tip!

 

Good guidance, thanks. I've got a bluetooth ODB and have downloaded Torque Pro. I just need to work out how I find the pressure readings...

 

Ultimately, it was just a matter of patience. I boosted the battery, cranked it over with foot hard to the floor for a while then took foot off the pedal and it fired.

As usual, I learned a couple of things in the process. The Torque app was a great piece of advice, thanks @NBCat