Hi all. My name is Mark and this is my first ever post. Please Help!


I have a 1996 4.0 XK8.


I have driven the car for several months with an intermittent 'Poor Performance' fault that usually cleared after a few seconds.


Last week two cylinders per bank stopped working. A basic code reader identified Engine fault: 'coil pack ECBH' (which would indicate that ignition module 1 had stopped working.) I noticed that each and every time the car will start on all eight cylinders, and then drops to four within seconds.
I purchased 2 working ignition modules and swapped all 4 about to make sure I had covered all angles.

Each swap produced the same results. 'Coil Pack ECBH' and the same four cylincers not firing - after starting on all eight.


I replaced the spark plugs with NGK BKR5EIX Iridium, and all 8 coil packs. I Performed a hard reset and tried again with no improvement.


What should I try next?

 

Welcome to the forum Mark,

Throwing parts at a Jaguar soon gets very expensive!

Get a code reader that will read Pxxxx (Powertrain) codes and post the actual codes back here.

A misfire sets a general P0300 code together with additional code(s) from P0301 to P0308 for each relevant cylinder. Switching coil packs between a reported error cylinder and a clear cylinder to see if the code changes helps indicate a faulty coil.

A hard reset will reset fuel trims to default but won't have any effect on a persistent DTC code.

Having changed all 8 plugs and coils you should have eliminated this as a source unless it's a faulty coil harness/connector. A suitable code reader/scantool is your best fiiend when troubleshooting Jaguars.

When you get a minute, please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

There might be two things getting confused. Your car has two ignition modules that provide the signals to the coil packs. I make the assumption that you purchased two ignition modules and then swapped the coil packs around. You can swap the wiring harness' around on the ignition modules and see if it stays or moves. Almost gotta be an ignition module or a connector issue.

 

The first year US cars have a common problem of ECU failure due to leaking capacitors. Mine had a misfire on two cylinders on each bank when it happened.

If swapping coils and ignition modules doesn't move the misfire to other cylinders that is likely your problem.

The ECU can be repaired and I expect there are services in the UK that can test and repair. Or contact ASI in Tennessee:

Automotive Scientific Inc. | Quality Rebuilt Automotive Electronics | Rogersville, TN

 

Hi all.
Thanks for all your comments and advice so far.


I have the fault codes as follows:


P0352 P0353 P0355 P0358 & P1368


The first four also have coil labels BCEH and the fifth is described as 'unidentified'.


Any further thoughts would be gratefully appreciated.


Cheers, Mark

 

Thanks Graham.

Thanks for all your comments and advice so far.

I have the fault codes as follows:

P0352 P0353 P0355 P0358 & P1368
The first four also have coil labels BCEH and the fifth is described as 'unidentified'.

Any further thoughts would be gratefully appreciated.

Cheers, Mark

 

[QUOTE=RJ237;1528808]The first year US cars have a common problem of ECU failure due to leaking capacitors. Mine had a misfire on two cylinders on each bank when it happened.

If swapping coils and ignition modules doesn't move the misfire to other cylinders that is likely your problem.



I found a UK company called Avilec Ltd, Cowes, Isle of Wight, who tested and repaired my ECU based on your diagnosis.


I got it back today and everything works as it should and I am delighted!


Thanks to everyone for their help and advice. I will try to learn more about this site in the event that one day I can be of help.

 

And we thank you for coming back and telling us the result. Far too often new members just disappear and we never know if the problem was resolved.