I have had this car for almost 10 years and it has been very reliable. I am beginning to do more of the work myself. Lately it has been running a bit rough when cold. Recently it went about a block from home and just died. I got it back home and checked to make sure fuel pump was functioning and there was spark at the coil (didn't have someone else to crank to check for spark lower down). Thinking it had fuel and spark I cranked (with a little jumper help from my other car) and it finally and quite reluctantly started. I let it run for 5 or 10 minutes and it seemed to be running fine. I decided to run down to the gas station. About a half mile into my trip it just up and went dead again. I called the wife from the cel and she brought the "jumper" vehicle. Again, after much cranking it fired up (reluctantly again). I was able to drive her home but ironically it went dead again as I was nearing my driveway. I thought it particularly interesting that whatever the problem, it allows the car to start, albeit not easy, and then drive about half a mile where it goes dead on me. Note that the electrical system is not failing and all lights and other electrical functions continue to work when car is "dying". I figured it must be fuel. I have not done any diagnostics on the diode cluster or relays as the fuel pump is pumping fuel upon cranking and running. Anybody have any ideas? My Haynes manual gives fault diagnosis for not starting when warm but not cold. Could my air intake be stuck or something putting me in a constant state of "choke" and when the car begins to warm it dies? As you all are aware, these cars have a a multitude of relays and gadgets like thermotime sensors, etc. I really don't want to flatbed to my mechanic if I can help it.

Thanks for your help in advance!!

Doug

Submitted by dougdwyer@eart… on Tue, 01/21/2003 - 00:36

I've had good service from Moss Motors, Xk's Unlimited, and Coventry West. They all have web sites. Lately Coventry West has been my favorite. Pauls Jaguar is a great source for wood, as is British Autowood.

Good luck and post back if more help needed

Doug Dwyer
JDRC/NWA

Submitted by dougburgy@msn.com on Tue, 01/21/2003 - 00:16

As I have been leaving it to my mechanic to find parts needed in the past or going to dealer and paying big prices (quoted $429.00 for fuel pump recently). Where can someone find just about anything for the XJ6 ser.III automobile? Relays, sensors, bushings, engine parts, etc, etc.

Also, anybody know good source for refinished, good quality burlwood for dash, consol, doors for VDP?

Thanks.
Doug

Submitted by SC20-30420CJ on Mon, 01/20/2003 - 22:39

Doug,
I probably confused the issue with my last post. The regulator is where you think it is. On the front of the fuel rail and inline after the injectors. It simply bypasses fuel back through the return line. To check fuel pressure, you need a tee fitting so you can attach your gauge inline. If you just connect the gauge directly to the pump, you won't get regulated pressure. You can connect it between the fuel feed line and the fuel rail.

Doug is probably closer to a diagnosis here than I am. A good look at the wiring is always the place to start for a problem that has suddenly cropped up.
John Testrake
President, Jaguar Association of Greater St. Louis

Submitted by dougburgy@msn.com on Mon, 01/20/2003 - 21:48

Fuel regulator the thing on the front side of the fuel rail (fan belt side) that looks like a disposable fuel filter (kind of)? The Haynes manual I have is fuzzy on this as it says it's for my model and year but it also shows me having duel fuel pumps. Something that perplexed me for
about 10 seconds before realizing that was my power antenna unit. Anyway, I deducted that the regulator would be between feed line and fuel rail but as John noted, the feed pipe feeds the fuel rail on the back (battery side) of the rail. I can't imagine that kind of tangled mass of fuel lines running under the engine. Can you confirm?

I am going to r/r the relays next to the diode pack just to cut down on diagnostic time (heck they are 17 years old for all I know). I will check fuel injector ballast pack as per Doug's notes and trouble shoot based on instructions found in link from John's post regarding "engine cranks but won't start" by Doug.

Appreciate you guys taking the time. First time posting and impressed with your wisdom and willingness to share with the ignorant (or was I supposed to enter a credit card number some place?)

Doug

Submitted by dougdwyer@eart… on Mon, 01/20/2003 - 20:54

If you think the system is in a "constant state of choke" then the most likely culprits are: the coolant temp sensor (cheap and easy as guesses go), a faulty/ruptured pressure regulator, or a malfunctioning tank changeover which allows one tank to over-fill and thereby allows raw fuel into the vapor cannister where it is drawn directly into the inlet manifold. Are you getting lots of black smoke?

Never underestimate the possibilty of a wiring or connector problem, especially at the coil, the firewall relays, and the injector ballast pack. Spend an hour going over the wiring and terminals *very carefully". You can't rush thru this step or you'll miss something for sure.

Remove the under-dash trim and try jiggling the wiring at the end of the ignition switch. If doing so alters anything, you've hit pay dirt. Ign switch failures are common.

The ignition coils themselves were also fairly well known for giving fits as the years and miles gradually take their toll. Couldn't hurt to replace it on GP and there's a more than fair chance it'll fix your problem. Don't forget to check the high tension lead from the coil to the dist cap....corroded ends spell trouble and, boy, talk about an easy fix.

The "main" and "fuel pump" relays can be intermittant. You can bypass them for diagnostic purposes, details on request. Or, just buy a replacement and swap it in at both locations and see if anything changes. Make sure to get one with 30-85-86-87-87 terminals and NOT one with 30-85-86-87-87A terminals. The Bosch number is 0 332 019 151.

Hope this hopes a little, post back if needed

Doug Dwyer
JDRC/NWA

Submitted by SC20-30420CJ on Mon, 01/20/2003 - 14:00

Hi Doug,
The pump should run while cranking and after engine start. You can check it by taking the fuel line off the rear of the fuel rail (near the battery) and hold it in a container while cranking. Fuel should come out. You can also check the fuel pump circuit by removing the air filter canister and pressing on the air flow meter flap with the key in "run". That should cause the pump to run. Finally, a weak pump will run but have too little pressure. You should have 36 psi after the regulator.

You mentioned that you needed a jumpstart. A weak/drained battery will cause the symptoms you have. You might just need a good charge. You can get the battery checked for free at most auto parts places like Autozone or Carquest.

There is an excellent "no start checklist" written by Doug Dwyer available at:http://www.jag-lovers.org/xjlovers/xjfaq/nostarts3.htm

and a fuel system trouble shooting guide by the same auther at:
http://www.jag-lovers.org/xjlovers/xjfaq/fuelpumpcheck.htm

Good luck and post back with your progress.

John Testrake
President, Jaguar Association of Greater St. Louis