Hi all. I had a thread a couple of years ago trying to solve this problem, https://www.jaguarforums.com/forum/x...needed-217884/

I'm going to try and keep this as short as possible. My 2000 XK8 has 3 codes. P0353, P0355, P0358.
This is what I've done so far to no avail.
1. New coils
2. New Spark plugs
3. Replaced wiring harness
4. New fuel pump
5. New fuel injectors
6. Refurbished computer from ATE
7. New battery when problem first presented itself. Battery is always on a charger

There might be more that I've done but it's been going on for over 2 years and I forget I still have the same problem. The car always starts right up, runs great for 5 seconds, and then rough idle. I just did a compression test. Engine cold (because I had the intake and other items removed and didn't want to take the time to attach everything to warm it up). Right bank, 122, 121, 119, 120. Left bank, 110, 114, 112, 112.

I'm at a loss as to what to do. I brought the car to a foreign car shop when I lived in CT. it was recommended to me by Wayne Carini. They had it for 2 weeks and could not figure out the problem. Their best guess was the wiring harness which I did replace (also doing a continuity test on the entire new loom).

Primary and secondary timing chain guides have been replaced as have the primary chains. I'm thinking my last option is to replace the engine but I was hoping someone could suggest something that I may have missed. I replaced the timing chains and guides in 2015 and the car ran great until taking out of storage in the spring of 2019. With all the work done, the same 3 codes always show up on my code reader.

Edit: I also used an in line spark tester and it showed power going to the plugs.

 

Given the codes, I seriously doubt a replacement engine would help, your issue is likely something electrical.

Have you check the end to end resistance from the ECM to the coils? Is your refurbished computer the same computer and it was repaired or you got a refurbished replacement?

 

The replacement ECM was a replacement. I shipped the original one to the company and they did the security copy to the new one. When I put the new to me wiring harness in, I checked continuity on all the wires. Everything checked out ok. It's pretty exasperating. If it's electrical, I can't figure where to begin looking. Using a coil/spark tester, it shows the wiring is working, coil is working, and it shows spark at the plug. Those cylinders are not functioning. If I remove the coil wire from one of the bad cylinders, nothing changes. Pull one from a functioning cylinder and the engine stumbles more. I did also replace the main wiring harness and also the harness that goes from the ECM to the firewall.

I also checked all of the ground connections on the body and everything seemed connected correctly with no rust.

 

How about swapping injectors?

 

Hmmm...if the spark plugs are sparking (reliably!), then it must be a fueling problem. You've put in new injectors and pump. Have you checked the fuel pressure? Fuel filter? Which cylinders are not working? Swap some injectors and see if the problem follows. Pull all the injectors and have them flowed. Doesn't take much crud to mess up an injector. Might even drain the fuel tank and have it cleaned.

 

FWIW, there is a common connection to 3A, 1B and 4B - where the coil feedback wires are connected to a splice on the harness, and then onward to the multiplug atop the transmission at pin 29. But... I'd expect to see P0352 (2A) at least intermittently as that also joins the splice.

The other 4 coils' feedback splice together and route to the ECM separately.

edit: re-read the DTC and the monitoring conditions are "Run engine steady < 2500 rpm > 5 seconds" so presumably any errors are ignored for the first 5 seconds during which your motor runs smoothly?

 

I can't see replacing the engine especially since it ran fine before storage then suddenly you have problems. Quick start, runs fine for 5 seconds then the same 3 cylinders fail? Does it kick down to idle then fail?Agree w/ CC that it's probably an electrical problem. You've replaced all the coils (brand?), you have spark at the three cylinders (per tester) that aren't functioning and have disconnected functioning cylinders (and it gets worse). I'm sure you've already done this but it's easy to swap coils and see if the problem follows the coil.

 

I don't know if the plugs are sparking reliably. My light shows they are sparking. The original injectors were sent to be refurbed when I got the car in 2014. They came back with a great report. All were replaced with new plugs about a 1 1/2 years ago chasing this problem. It made no change. I will try a new fuel filter as I replaced it 6 years ago.

 

This problem started when I took the car out of storage a couple of years ago. I decided before starting it to put new coils in as it has 120,000 miles on it the original coils. The problem started on startup. I had bought no name coils originally. I have since bought 4 NGK plugs and it made no difference.

 

I'll replace the fuel filter this week. I don't know, maybe the problem is in the fuel line. I tried to do a pressure test but wasn't able to get a good seal on my tester. It was showing 40psi at idle and the same at around 1500 rpm. Sorry, just a little frustrated.

 

On your other thread when you first had this same problem the car wouldn't go into closed loop - is it still the case now that you can't read the fuel trims etc?

 

Even if you're getting a spark at the plug, the ECM won't fire the injector for that cylinder to avoid raw fuel being dumped (and will inhibit CL for that bank) if it doesn't see the feedback pulses from the coil pack.

You should be able to confirm with a test lamp, or listen for the click with a stethoscope.

 

I haven't checked that recently. I'll do that soon.

 

I do have a stethoscope so I will check to see if the injectors are firing. I have to go visit my stepfather in the nursing home today so I won't get to this until this evening or tomorrow.

 

I bought a 2001 XKR last July. It was having the same issue which translated to a very good purchase price. I changed out all the coils and spark plugs. The original coils showed signs of being wet. A number of them had rust on them. I sealed the cover to try and eliminate moisture from entering. New covers are ridiculously expensive. The car has run great until about a month ago when It would code and run bed at start up. I'd shut it down and restart and it would be okay. It then coded P0354 and has since not run right. It has 69,000 miles on it. I am going to move two coils to see if the issue follows the #4 coil. If this doesn't work I am going to start testing grounds. Grounding can be an issue on all Jaguars apparently.
I am going to follow this post religiously. I got my car because of this issue forced the original owner into submission. I hope it doesn't force me into submission too.

 

I just did a check of the fuel injectors with a stethoscope. All of the injectors appeared to be ticking the same. I'll change out the fuel filter this weekend although I doubt it will help. It's a cheap test.

 

Hopefully we can help each other.

 

Well, now I have total failure. Working on the car yesterday, I was trying to get a solid check of the fuel pressure. I got a 39psi reading. I had replaced one cylinder with the original Denso plug that was taken out of the car a couple years ago. I also put the original Denso coil on that cylinder. With the car running, I unplugged that coil to see if there was any change in idle ( I've done this many, many times). That cylinder seemed to be working, and then the car stalled. Now it will not start. Crank but no start.

 

Never a good idea to remove any plug leads or coil packs with the engine running as the surge in HT can bugger the lot.
Looks like your luck ran out.
I would be looking at the units on the bulkhead that drive the coils..one for each side.

 

The AJ27 engine does not have ignition modules.