Hello can someone shed some light on this code? 1994 XJ81 What typically causes this? thanks for any help.

 

Hello,
If you Want yo Know more about your engine


94 XJ12 Sedan Technical Introduction S81.pdf

 

 

Wow thanks for the shop manual...much appreciated...I will try to locate and fix the problem.

 

Hi jagnut,

Note that the document frenchfairplaydriver posted is the Technical Introduction, not the Workshop Manual.

As far as I know, the full XJ40/XJ81 Workshop Manual is still only available from the Jaguar Daimler Heritage Trust on DVD-ROM, or possibly on eBay in paper form. I haven't found it online as a free pdf download, but you might search to see if a scan has been uploaded by someone.

The engine Service Manual can be downloaded here, although as always it assumes a lot of basic Jaguar engine knowledge:

Jaguar 6.0L V12 Service Manual

Another helpful reference is the Haynes XJ40 Repair Manual, which applies to most of the systems on your car with the exception of the engine and transmission:

Haynes XJ40 Repair Manual

Since XJ81s are less common than XJS V12s, you might search the XJS forum for FF36 and Code 36. For example:

https://www.jaguarforums.com/forum/x...e-light-65172/

Also this:

https://forums.jag-lovers.com/t/v12-...hey-are/134977

Cheers,

Don

 

Hi, jagnut,

Code 36 on your engine is telling you there is some kind of circuit fault detected by the Fueling ECU in the B-Bank Injector circuits. That can be a cut/chafed/shorted/grounded wire, a fault in an injector itself, or a fault in the Power Resistors to that Bank. Just anything in the actual wiring and components controlling the LH row of injectors. Attached is a manual section for your engine.

Good luck!

 

Hello and thanks for the information and downloads. I found a vacuum leak at the air injection rail.The rubber hoses that connect to each bank. One of the hoses had a split on the underside. Perhaps this is the problem? I have replaced and cleared code.I will report back in a day or so and see if this the culprit.Thanks for the suggestions any help. By the way , which is A-bank and which is B-bank? Thanks

 

Hello again...the code is back.I checked for wiring at injectors looks normal...listened to the injectors all are clicking on and off. Seems to be running rich. I am going to check the 02 sensors next? Need to know which is bank-B? Thanks for any help

 

 

thanks for the diagram...much appreciated....guess I will pull a plug and check the color to see if it is running rich...any thoughts??thanks

 

I decided to order a 02 sensor for B bank and will report back but the plugs on that bank have been running rich. Is there an easy to check the o2 sensor? thanks

 

How to test a lambda probe?
A lambda probe (O2 probe) is an automotive sensor, the purpose of which is to measure the level of dioxygen in the exhaust gases.
The lambda sensor is usually placed on the exhaust pipe between the exhaust manifold and the catalytic converter.
The measurement returned by the probe allows the computer to determine the proportion of the air-fuel mixture for which the efficiency of the engine will be optimal, with the aim of reducing pollution as well as consumption.
On recent vehicles (compatible with EURO-3 and E-OBD), in addition to this ("upstream") probe, a second probe is placed downstream of the catalytic converter, making it possible to evaluate the efficiency of this pot in time real.
The probes are subjected to very high temperatures, and sooner or later they break down.

In general, the failure results in the appearance of a warning light on the dashboard. There may be no other symptoms, depending on the vehicle; but on some, an increase in consumption and a decrease in nervousness are felt.

Test a Lambda probe
To test a lambda probe, you must have a multimeter that has the ohmetre function. I advise you a quality multimeter, for example of the brand Fluke. After disconnecting the probe, you will find that it generally has 4 wires. Locate the two wires of the same color, and test the continuity between the two pins corresponding to these wires. You must find a value between 5 and 7 ohms. Outside this range of values, your probe is most likely out of service.

 

Thanks for the information I will check as mentioned....much appreciated

 

Hello again, thanks for the help it was the o2 sensor..back in action..best regards

 

well that didn't help ...the ff36 is back on....driving me nuts...performance seems normal...I have ohmned injectors ok within specs....I can hear injector click when running all seem the same...looked at each injector connector clean and tight..is there a way to pull injector rails and watch the fuel spray patterns? I know I will have to kill spark. do you think this is worthwhile exercise? Back at it again...feel like I am going in circles thanks for anymore help. The vehicle is a 1994 LWB XJ12 (x81) with Marelli distributor. 6.0l. Thanks

 

Hi jagnut,

Please use your User Control Panel to add the year, model and engine details to your signature line so others don't have to go searching back through your thread to know what type of car you are working on.

Thanks!

Don

 

Hello again I think I am getting closer to the issue. I checked to see if the O2 sensors heaters are working. When I tested them I could only see 3 volts to either. Is there something I am missing? With ignition on and checking the third wire for battery voltage it only shows 3 volts. Hooking the wires back up and starting the car I pulled the o2 sensor relay on the firewall and the car shut down. Could the relay be bad and only passing 3 volts to the heaters? Any comments greatly appreciated

 

Ok finally, my problem was 2 leaking injectors on bank b. Evidently they did not close all the way causing over fueling.Sorry about the delay but just not enough time to keep up. thanks to all