Hi All,

I'm new here and hope to get some help on a few issues on my Jaguar xj6 with 83k I just got. All in all it runs great but there are a few issues.

1. Engine missing slightly. Car has new plugs according to previous owner, could it be cap and rotor? What usually is the cause of this?

2. Heater/AC Blower Motor does not seem to work. When I flip the fan switch, I just hear the vent servos make noise but no fan. What could this be? Common problem?

I am new to the series III xj6 as I had a 94 before this one. Are there any issues that I should know about? Suggestions as to caring for this car?

Car runs and rides well for the age, I'd just like to cure the miss, fix the blower issue and properly care for the car.

Thanks to all for your help!

Cheers!

 

Engine miss: more details, please. When do you feel it? What speed? Hot/cold engine?

Blowers: replace the fuses and clean the fuse contacts, report back if no help. (Note: the 50amp Lucas fuses are replaced by 30amp USA fuses)

Cheers
DD

 

Hello,

Miss seems to happen at any temp. I notice it most at idle and when first taking off. Seems once the car is moving you can't notice it. I only notice it at IDLE and when starting off.

I can feel the miss when I hold my hand over the tail pipe.

Thanks for any info you have.

 

Hello,

Another update on the miss and the heater issue.

1. Miss is so bad upon start (cold engine) that the car will stall unless it is heats up first before moving.

2. Fuses all ok on heater/ac blower. Blower does not work.

 

If the misbehavior on cold running is accompanied by some black smoke from from the exhaust you might have the infamous double-fueling problem

Here's the tech bulletin. It references "Canada" but the USA cars had the same issue


JAGUAR CANADA INC.

TECHNICAL SERVICE BULLETIN REFERENCE B-001 VOL V

MODEL XJ6 SERIES III 4.2

SUBJECT: AIR FLOW METER

It has been established that the cause of some 4.2 Series III engines misfiring and issuing black smoke from the exhaust when the car is accelerated or driven way with the engine in either a cold or part warm state, is due to overfuelling. This is produced by continuous triggering of the acceleration enrichment circuit during the warm up period (Note: There is no acceleration enrichment above 75*C).

The acceleration enrichment circuit can malfunction in this matter due to either poor or dirty connections on the airflow meter plug/socket connection.

Should this problem be reported, dealer should check and ensure that the air flow meter socket connections are clean and have good continuity.

Should dealers find that these actions do not resolve the overfuelling problems, the following Service Fix should be implemented.

A 100 Micro Farad, 25 Volt Electrolytic Capacitor should be soldered across terminals 6 and 8 of the Air Flow Meter harness multiplug ensuring that the negative lead of the capacitor is connected to terminal 6 and the positive lead of the capacitor is connected to terminal 8.

100 Micro Farad 25 Volt Electrolytic Capacitors are readily available from most reputable radio/electronic dealers.

__________________________________________________ ___________________________
If no black smoke I would check your coolant temp sensor which plays a critical role in engine fueling on a cold engine. It might not be commanding enough fuel. Do you have an ohm meter? If not you can replace it....only $20 or so.

Next, yes, it could be a cap/rotor/plug wire problem....but with one of those you'd normally still feel the problem after the engine warms up.

On the blower did you chack all three fuses or just the two in the fuse box? There's a thrid fuse behind the right side "cheek panle" at the forward end of the console

Cheers
DD

 

Thanks for the good info.

There is no black smoke. When at idle once warm, you can feel the slight miss, but it does not make the car stall once the car is warm.

Where is the temp sensor? If you can give me a round-about location I can test/get a new one. I'm still new to the series III part locations.

Also, you mentioned a third fuse. Do you mean the right side of the console where the the climate control unit is? I just need an idea of exactly what I am looking for. Thanks!

 

Coolant temp sensor: on the water rail, alongside the right cam cover, it'll be #2 or #3 from the front. I always forget. The one with a single terminal is for the dashboard temp gauge. The one with two terminals is the one you want....coolant temp sensor for the fuel injector system. it has a plastic connector that looks just like a fuel injector connector.

Fuse: remove the side panel that has the little ventilation grille that blow air down to your feet. Just two screws thru the little vent hold it in, then wriggle it forward. Look alongside the heater case and you'll see the inline fuse on brown or brown/yellow wires

Cheers
DD

 

Thanks again very helpful. I will be checking this out tomorrow. I'll report back with my findings. Once again much appreciated information!

 

Doug,

I tried the cap, rotor and new plugs. Still the miss is present. What should the OHM read on the meter for the tempature sensor? I have a meter but need to know what they should read in order to make sure it is working properly.

The heater issue is solved. Thanks for that information. It was the fuse that you mentioned.

I am just trying to correct this miss, as changing the plugs, cap and rotor is not the issue. I have plug wires on order just to be on the safe side, but if you can tell me what those sensors should read on the meter that would be great. Thanks.

 

http://www.jag-lovers.org/xjlovers/xjfaq/testcts.htm

Cheers
DD

 

Thanks. I believe the sensor may be bad, so I have one on order from the auto parts. It's a Bosch unit around $20.00.

I'll report back if the wires and sensor doesn't solve the problem.

One other thing, sounds like I have a bad back right wheel bearing. Are they difficult to do? I did my own on a volvo but I know it is probably a different set up on the jag. Thanks!

 

Setting up the clearances is a little tricky.

This shows the procedure:

http://www.youtube.com/watch?v=qdNyUeFyh4E

Cheers
DD

 

Doug,

I've done the following and still the miss. The miss is most prominent at idle and when you are accellerating between 0-20 mph. Seem to smooth out once you are going 40+ MPH.

1. Changed Dist cap and rotor
2. Put all new bosh plugs in
3. Just changed collant temp sensor with a bosch sensor

I am waiting for some new wires to come in too. I doubt this will fix the problem. All the injectors seem to be clicking away when I use a scope to listen to them.

What are your thoughts? I'd like to get this worked out as it is the only mechanical problem. The car has 84 k On it.

Thanks!!

 

Might be a clogged fuel injector. Even if they click, they may not all be flowing well. It is worth trying a good quality fuel injector cleaner in the gas tank. The fuel spray pattern might improve enough to eliminate a misfire.

 

Well, just replaced the wires and still not much luck. The car still sputters when accellerating and smooths out once on the road over 40 MPH. I've put some fuel cleaner in, but no difference.

Would fuel pump cause this? Perhaps more than one bad injector? I've replaced mostly all tuneup items and still no luck

 

It just doesn't sound like a fuel pump issue to me. Clogged injector(s) is more probable. If it's an injector problem one can of cleaner won't do the trick. It'll take repeated treatments...or have them professionally cleaned.

Couldn't hurt to check/replace the fuel filter....an inexpenisve guess if nothing else. If you do, empty the contents in a clean container to check for contaminants.

Cheers
DD

 

Thanks, Doug. I've got a few cans of cleaner to repeat treatment. I hear a professional treatment isn't too expensive. I hope I clear this up...I plan to try the fuel filter too. When they delivered the car, I can tell you it had NO gas in it. Perhaps some dirt got in the line from the low tank?

My next challenge will be back breaks and rotors. This rear breaking system is new to me, so if you know any good tutorials for this please let me know.

PS to all who read, never buy a car on Ebay. This car came from a dealer and has so many problems the dealer failed to disclose. They claim it was a daily driver. I paid 2700 for the car and so far invested over 1k in repars. Thankfully I can do most myself!

 

For rear brakes most prefer to drop the entire rear suspension...not as bad as it sounds and access is greatly improved. I can give you an approximate step-by-step when the time comes.

You can replace calipers and rotors with the rear suspension in place but removing the rotors requires that the car be elevated VERY high....much higer than most would be comfortable with.

Bad on the dealer for not disclosing defects but as a general rule 20-30 year old used cars are gonna need a chunk of money thrown at 'em...and Jags are no exception.

When you're done, though....you've got one of the world's greatest cars and not some crummy beater :-)

Cheers
DD

 

Yeah, I kinda figured it was going to need a little TLC for the age haha. I just didn't expect all the problems they didn't disclose. I absolutely love the series III and can't wait until I get the quirks worked out. I'll be in touch for the breaks when that time comes...I'm trying my best to figure out this miss.

Fuel filter and injector troubleshooting tomorrow. I'm sure I will report back with any findings. Thanks again for all the great advice!

 

Series IIIs are great cars. "The most modern of all antique autombiles" :-)

I'd like to have another some day.

Cheers
DD