Hello everyone,

Just wanted to introduce myself. I really do have a deep connection with my car because it has been a emotional roller-coaster just getting it to run. I purchased a 1986 XJ6 VP about 3 years ago while working and still enrolled in Highschool. Initial problems were cracked head gasket, timing belt issues, and a bad oxygen sensor and exterior wear and tear. The time between solving this issues has been long and spaced out quite a bit due to my small wages and busy schedule. But finally in February of this year it became drivable,(or so I thought) and had a Blast for the few months that my XJ6 ran.

I will do my best to post pictures or video.

Thank you for your time,
Robert

 

Hey, CrossheartXJ6 what are you saying - "timing belt" ? No Jaguar XJ6 engine ever had one of these.

 

Timing Chain rather.

 

So now the current problem is RANDOM stalling while driving. This problem presented itself after I replaced the fuel pump, Mind you I do not know if this has anything to do with it because I am not in any way a mechanic.

When the fuel pump died, My father ordered a replacement and noted it was suppose to be for a 88'. Im aware that the 88's were actually xj40's and had a smaller sized engine. He has told me that the stalling is a unrelated problem and is currently looking at the distributor cap or coolant temperature sensor.

Any information is helpful and I appreciate the time taken to read this message!

 

Does it restart after it cools down? If so you need to look at the ignition control module. Common failure in these cars(bad location, horrible ground & old , if any electrical grease).
It is a standard 4-pin GM ignition control module. It is in a black box bolted to the front of the intake manifold. Remove the 2 bolts holding it on, then remove the 4 small screws holding the rear plate on & you will see it. It is secured to the box with two small machine screws.

You SHOULD also replace the ignition coil at the same time. As a faulty module is hell on the coil. You can get BOTH at your local parts store for less than $50(any good parts store normally has them in stock). Tell them the module is for like a 1975 Suburban V8. Here is what it looks like(ignition module) & a SHORT list of vehicles it fits.
http://www.summitracing.com/parts/PR...ET&prefilter=1

They are both standard parts. I currently have a MSD control module(from summitracing, has a rev limiter built in) & a Nippon Denso tower coil from a TOYOTA on my car.

EDIT... A LOT of people will preach FUEL PRESSURE..while it is a concern, it is NOT a big deal. These cars can run just fine with 99% clogged injectors, clogged filter & a bad regulator. As long as the fuel pump works & pumps enough fuel to start the car, then do not worry about it.

 

Hello, I replaced both the Ignition module, and ignition coil. Despite the symptoms (Ive gone through 2 ignition coils) this particular fix does not seem to have helped. It still dies after running for a short while (although this duration of time is still at best random) After finally dying, 99.9% of the time it starts back up just fine only to have the same problems happen again.

Any information anyone can give is more then welcome, tomorrow I will do my best to upload photos and videos.

 

Should the next suspects be Fuel pressure regulator and or Coolant temperature sensor ?

 

http://www.youtube.com/watch?v=_dYdhZsS1aE

http://www.youtube.com/watch?v=CUskPzH-_I8

 

Hi Crossheart

Can you clarify exactly what engine you have, please. If it is the 4.2 straight 6 with the Lucas-built, Bosch L-Jetronic mass air flow meter, I think I might know what your trouble is.

 

Yes it is a 4.2 straight 6 with stock, Lucas AFM

 

You say it cuts out whilst underway. I had this problem around 1995, and it was usually when I was overtaking. I think I nearly left a pile of dung on the seat once when it happened at speed ! Funny thing was, once one got to the side of the road, and tried a restart, away it went.

So with advice from a chap who maintains Jaguars near Liverpool, I finally rigged up a light bulb with a long set of wires which I managed to connect at the fuel pump so the bulb came on whilst the engine was running, and I could see the light whilst driving along. Next time the engine cut out, the bulb went out, so the electric supply to the pump had somehow disappeared. Tracking everything back with the help of a wiring diagram, I finally found out that there are two tiny contacts inside the MFM. The meter has a flap that moves thus allowing a Wheatstone Bridge set-up in the MFM to give an indication of mass air flow, however it also has these contacts, which are open when the engine is not running as the flap opens them when it is at rest. The current through these contacts can only be small, but it is the volts that are important as they are used to switch the fuel system relay on. When starting the car, the contacts are by-passed, (obviously), to activate the fuel system and pump, then when one releases the key back from 'Start' to 'Run', the bypass is switched out and the voltage via the contacts, (by now open because the flap has movedout of the way), keeps the relay switched. Over time the springiness in the contacts gets weak so they intermittently lose contact, thus switching off the fuel relay, and hence the pump. I had thought it was the inertia (crash) switch, but no. Years later, I read on the AJ6 Engineering website all about this little contacts problem that nobody at Jaguar ever mentioned. Maybe they were all too scared they would be fired.

Have a read here: -
http://www.jagweb.com/aj6eng/42efi/index.php

Worth a try.........

 

To save you reading all 6 pages........
AIRFLOW METER PROBLEMS

There can be no doubt that many L Jetronic problems involve the airflow meter, not that it is particularly troublesome but it does have several key functions and a fault in any of them is equally inconvenient. One of the most common is for the fuel pump relay switch across terminals 36 & 39 to cease to close properly. The cure is usually just to remove the black plastic cover (which involves some patient work with a sharp knife to gradually break the glue joint) and gently bend the switch contact arms until they close as the flap opens. If the switch is broken then the airflow meter will usually have to be replaced.

 

while attempting to fix one of the contact arms of the AFM it broke off. lol....Guess i'll be replacing it...

just my luck

 

Interesting, subscribed.

Like the idea of the video's.

Notice that you appear to have zero oil pressure.

 

Pulled a AFM from the pickapart, same problem. Not sure if the oil gauge is just malfunctioning or not. i'll have to go check.

where should I go from here if the same problem has persisted through another AFM? I know there is the likely hood that they were both bad....

 

just as a curiosity; does the electronic ignitions have a play in this problem ?

I replaced the AFM today with one picked from a junked jag. Then put a capacitor on wires 6 and 8. no improvement in the drive. if anything the problems are reoccurring more and more frequently.

I'll be uploading another video tonight when i can, not much is new in this just doing my best to document whats going on.

http://www.youtube.com/watch?v=ecWCjQgiGZo

 

Using a jumper wire with clips to apply 12v from the battery "+" post to the "+" post of the ignition coil....the post with the soild wire wires. Tell us if anything changes.

Remove the connector from the coolant temp sensor (on the water rail, third sensor from the front) and use a paper clip to jump the terminals inside the connector. Tell us if anything changes. Make sure the terminals are in good shape.

Unplug the fuel pump relay it's socket. In the socket identify the terminal for the white green wires. Using a jumper wire apply 12v from the battery to the terminals for the white/green wires. Tell us if anything changes.

Do you still have the old fuel filter? If so, shake out the contents (or cut it open). Brown crud is an important clue ! Or, remove your new fuel filter and shake it out. Along those lines it seems like your fuel pump is very loud....it might be straining against a restriction.

You mentioned in the vid that jiggling the engine wires cause the engine to react. Check the wires to the coil, fuel injectors, firewall relays, and injector ballast very carefully. Engine heat makes them brittle and they can short out (or go "open circuit") intermittently. Check/clean any connectors along the way. Many problems are caused by dirty/loose connectors. The injector ballast, by the way, is on the right inner fenderwell, well forward, and low. It is silver and approximately rectangular. Check/clean/jiggle the connection.

At the rear of the water rail is a bundle of ground wires for the fuel injection system. Make sure they are clean and tight.

Post back !

Cheers
DD

 

Good advice on other checks to carry out; these cars can be a real pain on the a*rse to sort out.

Other thing is to check the fuel pick-up filters in the fuel tanks. These are accessed via the large hole in the rear lower 1/4 panels below the side bumpers. There may be a rubber 'bung' covering the hole in which case remove it. You will find a screwed in plug of (I think) brass, which when removed will show the filters. They need to be clear. Be careful, because taking these plugs out will immediately drain the petrol in tank. It is best to arrange to drain the fuel into jerry cans bu loosening the plug ans using a funnel. Make sure nobody is smoking nearby or any machinery running. Alternative is to syphon-off via the filler caps direct into the can.

 

I haven't yet determined if jiggling any particular wire helps evoke the problem. but it definitely is occurring sooner and sooner. I'll try the other tests and postt back with another video later on.

 

Hang on in there !! It took me a long time to sort out my '80. After that it just ran and ran. Mind you it got a bit hot 'n bothered once on holiday in Waterford in a traffic hold up in 90F summer heat. Didn't boil, though.