Sunday 2 July, 2017.

Hi Everyone. As usual, I'm looking to you for suggestions.

Just bought a black beauty 1997 Jaguar XK8 Convertible (picture attached). Delivered to my home Wednesday. Only 140,000 miles on a 20 year old, 4 owner car.

Today was my first opportunity to take it for a drive.

Went to flea market about 20 miles away. Everything working. On return, about 4 miles from home, rolling maybe 45 mph, suddenly, without warning or any symptoms, RPM drops to zero. Quickly navigate off pavement onto apron. Shut off A/C, radio, and open windows. Wife says she smells burning, but it was only me burning up.

Waited maybe 5 minutes. Car started right up, and we continued home without incident.

It seemed like it just coasted to a stop and ran out of fuel. Not possible, just put 15 gallons for first fill-up 20 minutes earlier.

Any one have any ideas?

Very respectfully, Bob G.

 

Throttle body.
Common issue with early XK8s.
We need codes to start a proper analysis, but that would be my best guess so far.

 

^^ What he said. There is a related TSB - see Gus' site:
http://www.jagrepair.com/images/TSB/...20Throttle.pdf

or possibly fuel pump.

 

Random drop dead cut off like that could very well be the ECU. They are frequently in need of a rebuild. My understanding is that if after a cut off like that you have no codes, then the ECU is likely at fault.

Best of luck, keep us posted.

 

Hello DevonDavid. MichaelH, and FMertz.

Thank each of you for responding so quickly. It is always a pleasure to learn from each of you.


The fault code is P0706. My simple lookup table says transmission fault. The Jaguar Forums on this code suggested a good cleaning of the contacts below the shifter J-gate.

Next, I followed the link to the 14-page TSB. The car is an early '97 and this sure sounds like what happened. At the end of the 12 page procedure, it says it could be fixed under dealer warranty, instead of me taking the throttle body apart, searching for replacement parts, and begging/borrowing for the right software to reprogram. Does anyone know if warranty still is true for a 20-year old, 5th owner car? My previously experiences with my nearest Florida dealer (60 miles away) have been somewhat disappointing -- actually I am being very generous in saying this.

With it Sunday evening, I think I will postpone any further outside action tonight, since I am in Florida and the mosquitoes are rampant at dusk. Besides, everything always looks better in the morning.

Very respectfully, Bob G.

 

No chance it's still warranty. I'm sure someone here has documented the procedure for you.

Best of luck and I hope this doesn't sour your ownership.

 

Hello MichaelH and others following this thread.

Thank you for providing the TSB link. I reviewed it and bulletin 303-S514 says my VIN needs the ECM reprogrammed. This agrees with the suggestion from fmertz.

I called Jaguar in Mahwah, NJ and learned that this TSB was performed on my car in 2009 reported as 514C. Had it not been performed, I still could take it to a dealer at no cost. (Surprise, actually some help from Jaguar.)

So, still left with the problem. Everything in the TSB was spot on with one exception. At the moment of the incident, the RPM briefly increased, but the car continued to roll to a stop. Then the RPM went to zero.

Any other thoughts? Tomorrow is Independence Day and I would like to try to make this one enjoy freedom from becoming a garage queen.

Best regards and happy holiday to all, Bob G.

 

Hi Bob,
AFAIK the TSB closed in 2009 so good to hear that the dealer has taken a responsible stance given the safety aspect of the issue. I had to chase the local dealer to get it done.

The solution for the early cars was indeed a reprogram of the ECM, so in the absence of any TB-related codes, fmertz is likely on the right track.

I believe ASI are the go-to people on your side of the pond to check it out, although that inevitably means a down-time.

You're building up quite a collection

edit: just found this post by brgjag- may be a pointer?
https://www.jaguarforums.com/forum/x...5/#post1596867

 

A slight increase in rpm before it died is consistent with a loss of fuel flow. Suggest you do the fuel pump test next.

 

This may be one of those "tricky to diagnose" issues. The code - P0706 - would certainly point to a problem with the J Gate or transmission rotary switch but - that would put the car into "limp mode" rather than the total shutdown you have experienced.

Have a look at your throttle body - is there a small sticker with an "eye" icon on it. That would indicate it has been replaced with the updated version at some point in the past. The "eye" sticker is to refer you to the manual which says "Don't clean me - I have a special coating". If you have no sticker, there's no harm in removing the intake bellows and giving the inside of the throttle body a good clean with brake-cleaner or IPA particularly around the "ring" where the butterfly closes. My understanding of this issue is that - because the cable operates a potentiometer which operates a motor which is what actually moves the butterfly - there are occasions - usually on the overrun - where the butterfly closes and there isn't sufficient vacuum to re-open it because of the sticky deposits that have built up. (That's a bit over-simplistic but you get the point !)

I would try that first - it costs pretty much nothing, takes 30 minutes, and may narrow down the source of the problem. If it DOES turn out to be the throttle body, it may be cheaper to replace rather than repair - many Jaguar dealers were given replacements for use under warranty and these are now being sold ioff at a big discount. I paid less than £240.00 for mine a couple of years ago.

 

I agree with both Devon David and mhminnich. The culprit is fuel related, whether the fuel pump or throttle body. I was driving on the "straight and narrow" about 45 mph. When it died, the RPM briefly increased as the car slowed. Pressing harder on the accelerator did nothing. I agree that the wheels turning against the pavement continued to provide energy to keep the brakes, power steering, and A/C running.

Today I will check for the "eye sticker" on the throttle body. Depending on the discovery, then perhaps brake cleaner. Then the fuel pump test from my workshop manual.

Thank you both for sticking with me. I greatly appreciate the help.

Very respectfully, Bob G.

 

You might check the fuel pump relay contacts to see if they are BURNT.
Failing relay contacts can make the fuel pump do strange things.
A clogged fuel filter can strain the pump and draw more current than normal putting more of a load on the relay.

bob

 

Thanks. That's a great suggestion and easy to do. I appreciate the tip. Very respectfully, Bob g

 

Dear Devon David. Removed air duct from throttle body. No sticker. Sprayed throat with brake cleaner, wiped throat. Resprayed. Next, check relay contacts for burnt marks.

 

All relay contacts shine brightly. No evidence of burn or ware.

Can an anyone please tell me where fuel filter is located ?

 

Fuel filter is a small (silver) canister tucked up just behind the rear wheel on the left-hand side (driver's in US, passenger's in UK). It is behind a heat shield so not that easy to see. If you take the rear wheel off with the car on a jack/axle stand - it's not a difficult job. Early cars have "nut" connections - later cars have push-fit connectors which require a special tool. Yours should be an early one.
This video should help :

 

Hello DevonDavid and others helping. Thanks for the tip on finding the fuel filter. I never would have guessed that location in a hundred years. I've tried everything. Let me pose a new possibility.

I just bought the car. Sunday was its first drive. 20 miles out. On return, about 10 miles to go, I filled the gas tank. First time. Car needed 15.7 gallons. That surprised me. I remember looking on the ground to see if it was spilling out.

Then 6 miles later I have the incident described. I never remembered putting 15+ gallons in either of my other XKs. I usually fill at 10-11 gallons.

So here's the question. Perhaps this fill was extraordinary large, and I dislodged some debris from the tank, which worked its way into the system far enough to briefly cut off fuel flow. This never happened before in my life, and I've been driving almost 55 years. Any thoughts? Very respectfully, Bob g

 

Bob.
According to the handbook, the total capacity of the fuel tank is 19.8 US gallons. I'm an owner not an expert, but I think it's quite possible that if the car had been "dormant" for some time with very little fuel in the tank, and then it got filled up and sloshed around a bit, then some debris could have got dislodged and sucked into the filter.

If you look at the engine - left-hand side near the front - there's a "Schrader valve) like a tyre valve on the fuel rail. Run the engine, switch off, then press the centre pin and, if you get lots of gas in your eye - your fuel pump is probably OK.

 

Just checking DevonDavid. Left-hand side near the front --- for a US car with LHD? Sometimes I get excellent information and tips from the UK, and left means right.

It's nighttime where I am now, so I'll be looking first thing in the morning.

Cheers!

Very respectfully, Bob G.

 

Here you go ...................