Hello, I go by Mauido.I am a new member currently living on the island of Maui in the state of Hawaii. I own a 1990 XJ6 Sovereign with 120k miles.Recently the car started running rough and died and would not start up. I replaced the ignition coil, crankshaft sensor and fuel filter.It took a while but fired up and ran perfectly after. About week later, all the same problems are recurring again.Rough running on start then smooths out. But when placed in drive low acceleration and dies.I get a fuel failure 69 code. Wha'st a guy on Maui to do.Help would be greatly appreciated. Thanks

 

Welcome to the forum Mauido,

I've copied this question from your Intro for advice from members with the same model.

Graham

 

Thanks for the direction.This is all very new to me and I need help. Once again Thanks

 

Hi Mauido,

Welcome to the Jaguar Forums! It's great to have you with us.

I'm sorry to hear you're having trouble with your XJ40 (the Jaguar factory project code for your 1990 XJ6).

First of all, Fuel Fail 69 probably has nothing to do with your rough running. It's a Diagnostic Trouble Code (DTC) that indicates a problem with the Park/Neutral switch in the gear selector mechanism. The engine must have been cranked in Drive or another gear other than Park or Neutral. Usually the switch just needs to be adjusted or cleaned, occasionally it may need to be replaced. There is probably a lot of information about the Park/Neutral switch already in the forums, just use the Search window at the top of this page.

It is possible that you have more than one DTC stored, but in the XJ40 only one is displayed at a time. If you disconnect the battery for 30 seconds or so, you will clear all stored codes, which won't be helpful. Instead, try the method outlined in the post at this link, which works on our '93 and may work on your '90:

https://www.jaguarforums.com/forum/x...1/#post1085399

Once you know if you have additional fault codes stored, please report them here and we'll go from there.

If you don't have any service manuals for your car, I would highly recommend that you download the XJ40 Haynes manual and Diagnostic Troubleshooting Guide from the XJ40 'HOW TO' quick links thread near the top of the home page for this XJ40 forum, and also order the official XJ40 service DVDs from the Jaguar Daimler Heritage Trust (jaguarheritage.com, look under Technical Publications), which will give you the same information as Jaguar service technicians:

Jaguar Heritage. MKI & MKII INC. 240 & 340 1955-1969 (JHM1117)

Jaguar Heritage. XJ40 (XJ6 & XJ12) SUPPLEMENTARY MODEL & SERVICE INFORMATION JHM 1130


There are a number of issues that can cause rough running and stalling, and often these symptoms are due to a combination of multiple issues.

If the problem seemed to begin suddenly, especially soon after filling up with gasoline, I would suspect bad fuel or fuel contaminated with water. Since things improved when you replaced the fuel filter but have gotten worse, it's possible that your fuel has water in it and has now fouled the second fuel filter. It's not easy to drain fuel from the bottom of the tank due to the location of the hose fittings, nor is it easy to siphon it from the fuel filler neck due to internal baffles inside the tank. It might be easiest to disconnect the fuel line from the inlet end of the fuel rail (closest to the firewall), position a suitable plastic or glass container to catch the fuel that will emerge from the hose, then turn the key to Position II to run the fuel filter briefly. Allow the fuel captured in the container to decant overnight and then inspect it carefully for water at the bottom of the container. If you find water, you could try adding a product like HEET to your fuel tank to see if you can burn the water through the engine, then when things have improved, replace the fuel filter again.

You don't mention how long it's been since you gave the car a good tuneup, but since some of the possible contributors to your symptoms would be replaced during a tuneup, it might be a good time to replace them now just to rule them out: Air filter, distributor cap, distributor rotor button, spark plug wires, spark plugs, and another fuel filter once you’re sure any water in the tank has been dealt with.

Other possible causes include an air leak in the air intake plumbing, a vacuum leak, a problem with the fuel pump, fuel pump relay or fuel pump wiring circuit, a failing or leaking fuel pressure regulator, a stuck-open EGR valve or leak in the EGR plumbing, a lazy or stuck O2 sensor, and probably other things I haven’t thought of. Also, hopefully this isn’t your problem, but on some XJ40s problems with the EVAP system can cause so much vacuum in the fuel tank that the tank collapses.

Sorry for the overlong reply, but hopefully you’ll find one or more additional fault codes that will steer you in the right direction, or it’s something as simple as water in the fuel.

Cheers,

Don

 

Hey Don,

Thank you so much for sharing your insight.As you suggested I cleared the vcm.Only recurring fault code is 26.You were dead on regarding the oxygen sensor.Ordered part and will keep you up-to-date.Once again thanks.

Mauido