I know You've checked fuel pressure but can I just give you some advice.
As quoted the XJR/V12 has two fuel pumps. One is used to start the car. It then switches over to run on the other. The pump that started the car is then only used under extreme load conditions to provide extra pressure/volume.

Maybe look at temporarily wiring up the pump that is starting the car and see if it continues to run on after.

I'm on my phone so I can't view the wiring diagram therefore I am not sure if there are 2 fuel pump relays in the boot or just one.

Hope that helps

 

I may be wrong, but I thought the second pump kicks in under load.

But here is the new twist. The knock sensors fault code has been on for over a year. But all of this new stuff happened since putting in the new crank sensor. But I did have the battery out of the car. Had battery tested. Shows good.

I have the ELM 327 and the app on my phone. If I try and clear fault logs, it simply does nothing.

To recap, now as soon as you start the car, all lights except the check engine light go out, but as soon as you get going, maybe 5 miles a hour, TRAC Fail, Traction lock off, and the ABS light comes on.

My ELM shows the voltage on the ECU varying from 8-14 volts, depending on rpm, yet when I check any positive post to ground, it shows a steady 13.6 volts. Checked at the battery, same. So for some reason, either my ELM is incorrect, or I am getting a bad connection somewhere. I read on here that the ECU pins get dirty. Does this require disconnect of battery? This car is really clean in the trunk, elsewhere.

I have planned a road trip this weekend, would love to get to the bottom of this tomorrow.

 

Oh yeah, here are the fault codes again....P0332, P0300, P0304, P01316. Under the tab of Pending fault codes, I get B30f4, and B13b0. And yes, they are in lower case letters.

 

Um i used to have ELM, its such piece of **** wouldn't even clear any code and sometimes it just refuses to read. so i end up getting a better scanner. on my xjr6 i used to have TRAC fail, trac off abs light come on after a few miles down the road and ELM couldn't even pull the code so i used my other scan tool turns out it is c1095 abs module circuit failure (forgot the exact name of the code) anyways i was really hoping that i did not have to take the module out and send it to refurbish but i just had to check all the wiring around the wheel and stuff before i take that out, while i was at it i bleed all my brakes and changed my fluid and the code never came back again.

 

I had an XJR that would start but not run. Turned out to be fuel pump. Made even more confusing as it had fuel pressure when starting.
I think Jaguar had it this way so that both pumps got used. Makes sense when you think about it.

One relay in fuse box. One relay by battery I believe.

Just trying to give you things to consider.

I don't have an XJR so can't test the theory.

 

Well, as I've posted, the car is running now. Running as good as ever. But all of these lights! I don't like it a bit.

 

Ok guys, the lights went out as mysteriously as they came on. But I still am showing fault codes. Any idea how I can reset these?

 

disconnecting battery for couple minutes far as i know resets ecu and CEL codes on all cars you said you took it out to charge and check it so if you have them again likely you still have an issue you need to resolve

 

I had the battery out for a day or two, but the trouble codes stayed, and are the same. The codes indicate random misfire, misfire on cylinder 4, a knock sensor out of range, and emissions exceed range. But the car runs great.

 

Coil fault ?

 

From post #2 above, and brought up later by FrozenApple, your ELM doesn't seem to have the capability to clear the codes? If the car is truly running great, once the codes are cleared they probably won't come back. Time for a new scanner? Or perhaps the auto parts store will clear it for you.

Interesting point: Your CKPS showed 200 rpm during cranking, and it showed direct resistance of 1.394 Ohms, which is about right in my experience. Still, replacing it proved that it was bad, despite the evidence!

When I had a CKPS go bad, it would cause all kinds of lurching and missing during any acceleration. Yet it also passed those tests.

Excellent to hear that it was a relatively simple fix after all! It's the diagnosis that is so sometimes.

Big thanks to all the great suggestions made in this thread. Congrats to Robxjr6 for being first to suggest CKPS and "winning" the diagnosis in post #9!

 

I'm really glad to get the car going, and I certainly appreciate the advice given. For 116.00 at O'Rielly auto parts, and a little time, I now have a great running Jag again. We even went on a road trip yesterday with my club, and the car did great.

Yet, I now have more fault codes than I did prior to the CKPS going bad. I would love to reset the fault codes, and see if it was the CKPS that tripped a lot of this to begin with. The auto parts stores seem to have a problem resetting codes. The guy I had scan the car had no idea how to check voltage of the CPU. Do any of you guys recommend another scanner? I got the idea for the ELM327 on here.

 

Have you guys forgotten me? I put in the new crank sensor, which got the car running, but still shows codes P0332, P0300, P0304, and P1316. No idea how to reset the codes, see if they come back. Any guidance appreciated, as car seems to be running great.

 

autozone? borrow a proper scanner and clear the code? elm is like a piece of ****

 

I've got an old Actron 9145 which will read the 'major' codes and clear them all. It works OK but won't show more advanced information such as per cylinder misfires.

I have the 9145 because it reads OBDI and OBDII as well as the unusual OBD 1.5 (OBD 1 computer, OBD 2 wiring), which I require for my 1995 Buick Riviera which is OBD1.5

But need to get another for the Jag that is more comprehensive (again for things like cylinder misfire reporting) and affordable.

There are a few threads here discussing readers:

https://www.jaguarforums.com/forum/x...reader-114409/

https://www.jaguarforums.com/forum/x...one-buy-98444/



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