]Hi. I have a 99 xk8 convertible. I was driving down the road at about 40 mph and it just shut down. Luckily I was able to coast into a gas station. I tried starting it several times but no success. I have an OBD 2 code reader and these are the codes that came up...
All 8 cylinder misfire codes
P1367
P1368

I have checked all ground wires, coil packs, cam shaft position sensors & replaced the spark plugs one day prior to this happening. I did double check plugs type to ensure the right plugs were installed.
All 8 cylinders are down. Also i have been using the valet key for about 2 1/2 years. I dont have master keys. Dont know if that would trigger a security issue. But almost 3 years later? Probably not. Also was thinking maybe the ECM? Any ideas or advice would be appreciated. Thanks....

 

Do a compression test. Verify fuel pressure with a gauge.

 

At least check the fuel pressure by depressing the pin of the schrader valve on the fuel rail after turning the key on/off. If it doesn't give a good spurt it would be a good idea to check with a pressure gauge for about 40 psi.

 

It sounds like a fuel pump issue, It can quit and throw no codes. Did you clear the codes and crank it to see if it threw the same codes?

 

I did a fuel pressure test the way you mentioned and yes fuel pressure was just a trickle. Not even close to 40 psi. So i will definetly replace pump. I just didnt have any codes showing fuel pump. But thats not unheard of according to you guys. Would that shut down all cylinders?

 

Yes, it would. You may have two simultaneous problems but I would not expect that. There are other reasons for the pump to not be running, such as a blown fuse or failed pump relay, and it would be good to check before proceeding with the pump replacement.

Do you plan on doing this yourself or having a repair shop take care of it? I suggest you avoid going to a dealer, as they have a tendency to find many other 'faults' which could far exceed the value of the car.

 

Ya im doing it myself. Can't afford the jag dealer. Ive checked all relays and fuses.

 

Yes, the fuel pump failure does not set a specific code (only the much rarer fuel pump relay failure does), and no fuel could certainly trigger an all cylinder misfire.

 

Debibean, I live in Sac. and I'll be in Rancho tomorrow is there anything you need to help you get your repairs done?

 

Well now things are a little stranger...while troubleshooting all this misc stuff over the past few days the car just turns over but doesnt start. Because of that my battery ran low so i just hooked it up to another cars battery to give it juice to check fuel pressure etc. I went to turn it over and it just clicks now. The connections are good on the hookup between cars. So i pulled the key out and the windshield wipers real slowly inched their way across the windshield. Dash lights and instruments come on and interior light. But door locks, trunk release, windows and lights dont work. But the wiper thing happened several times with the key out of the ignition. Car will not turn over as it did earlier. It just is dead. Nothing. What in the world is going on? This brings me back to the ECM?

 

Thank u so much for the offer. At this point i just need to come up with some money to get whatever parts i need. I will probably go to British Recyclers over off Recycle Rd to get some stuff. Since im not 100% sure whats gonna fix it i need to get used parts and then new ones when i know exactly the issue. What a mess.

 

See if you can just connect a known good battery without jumper cables. Many jumper cables cannot power the electronics AND run the starter due to the very high current demands this car has and the sensitive electronics that expects full battery voltage.

 

You may have cranked your battery down from trying to start it get a good charge on your battery or hook up a good battery,like Steve says. These cars can do all kinds of strange things with a low battery.

 

I have checked all ground wires, coil packs, cam shaft position sensors & replaced the spark plugs one day prior to this happening.

Seems a bit too much of a coincidence .............. would be worth going back over everything you did to check that all connectors got properly re-connected, and that nothing got dislodged or disturbed during that work.

 

A faulty, damaged coil pack?

 

I have been replacing coil packs here and there due to a slight oil leak at the valve cover. So many have been replaced already. I took friday and today off from working on it to clear my head and regroup. I will try the battery idea and either get a charged one or fully charge mine. Ive got high hopes for the fuel pump fix. I'll update. Thanks for the input thus far in the investigation. 😷

 

Looks like the battery was the cause of all the weird things the car was doing. Things such as windshield wipers going haywire, windows & trunk not working, car no longer turning over, etc. All with the ignition key in my hand. As mentioned in earlier posts a low battery will really cause some problems. So that is resolved. Now im back to the original shutdown problem. Tomorrow i am changing the fuel pump ( many thanks to member Bobroy &#128567. I have high hopes that this solves all my problems.

 

Hi Debbi,

We had the same issue about 18 months ago with my wife's XKR. It was in fact the fuel pumps. This is a PIA job so If you can get some help it would be nice. I did it by myself with a half lift system I have in my garage and it was a Job. take your time and look up a few of the threads on this forum they were excellent. the biggest issue is releasing the fuel lines going into the tank neat the differential. I ended up making a plastic release tool our of 1/2 cpvc pipe. since my hands were too big to get into the tight space. Take your time when removing the tank out of the trunk so you don't cut wiring harnesses. I taped the edges prior to pulling it out.

Best of luck and when you get frustrated take a break and go at again.

Mike

 

The battery condition is so critical because our cars require specific levels of power for the electronics to function properly. The most important of these are the electronic modules [micro processors] which in operate the car in a normal fashion.

So even when a battery appears OK because it has a normal voltage reading, or it can crank the engine over; there may not be enough energy to power up each and every system. When that happens, the modules go bonkers and do crazy things. Things that are not logical, and therefore, nearly impossible to diagnose. e.g., The wipers operate very slow, and we immediately begin to look at the wipers, and not the module that controls them.

So when members here advise to first confirm the battery is OK, they are not asking if the battery has 12.8 volts, or if the headlights dim when you crank the engine. They are saying one needs to confirm it meets minimum operating standards via a bond fide battery test, which includes a slow charge, cell testing, load testing etc. These are tests most home mechanics can not perform.

I am fortunate to have an Interstate dealer a half mile from home. So I go there and get the test done by them. If there is any question about the battery's performance, I will get a new battery. Because I know even the marginally OK batteries can cause wonky problems that confound myself and everyone else on here trying to help me.

 

Well i made the mistake of not first reading your post about pulling the tank too far forward and disconnecting the fuel lines. Everything you said was right on the money Mike...the tank got pulled just a bit too far forward and they did get disconnected. Unfortunately i didnt know that had happened and went right on ahead and turned it over several times. Totally unaware of those lines being off. So as you would imagine fuel was everywhere. After many hours trying to reconnect them, which is a nightmare, we called it a day. Now i have read your post and am attemping to get it all straightened out. Bought new fuel line retaineing clips (ford ones were as close as i could get and they fit fine) and lines are officially reconnected! Also i found the ' ignition coil supply' fuse in the passenger side under hood fuse box was burned out. I was 99% sure all fuses were checked when this whole thing began, apparently i was wrong. Changed out fuse and fuel pump and getting ready to try starting it shortly. The suspense is killing me. I will post what the verdict is soon.