JTIS says it is removed from below with the vehicle on a ramp. Friendly main dealer says from below, but described the job in terms which I won't repeat in case any minors read this post! As described above, accessing some of the attachment points is the issue.
For what it is worth, I don't think the throttle body is superchargedtr6's problem.
I would be interested to see whether there is a sustained fuel flow, perhaps by disconnecting the feed pipe, and pumping into a container. Has the fuel filter been replaced? I know you have recorded fuel pressure, but if the filter is blocked or contaminated, once fluid starts to flow, the blockage could move. And I take it the fluid is petrol? could there be water or other contaminants in the tank?

 

Contaminates aren't out of the question, but I doubt it. The car ran perfectly for about 20 minutes, then acted up when I pulled away from a light. It does act just like its out of fuel. I've not changed the fuel filter, but will. Want to check volume, just not sure how to make fuel pump continue to run so I can measure volume.

 

Worked on it again tonight. Changed the fuel filter. If I put a fuel line on it, and then put the end in a jug, it seems to have a good flow until the pump shuts off. Showing 40psi on the gauge I t'd in. The fuel filter made no difference. The car started immediately, but then shuts down. I'm at a loss here

 

quick question about the fuel filter, i tried removing mine the other day but it was damn tight, i cant even turn the nut at all. and the other side seem to be extremely tight as well can barely fit a wrench in it. How did you get to both side?

 

Frozen Apple,
It is a PITA to remove the fuel filter, as you have discovered, not helped by the fact that it is ofter overlooked, and may not have been changed for a long time!
Releasing fluid helps, as does the right length of spanner , so you can clear the various suspension and exhaust components, and it is important to put a spanner on the end of the fuel filter too to stop it from turning. If your fuel pipes are at all corroded, great care is required to avoid folding or creasing them as you apply torque , as it is a major pain and expense to replace them - ask me how I know!
Finally, watch out for the tiny O-ring which goes on the end of each pipe which goes into the filter. Easily dislodged as you remove the pipe, and fuel leakage guaranteed without it.

 

Superchargedtr6,
Sorry to hear you still have the problem, but no harm in changing the fuel filter.
What about wiring a temporary supply directly to the fuel pump to see whether she will keep running then? I don't have a wiring diagram in front of me, but you should be able to achieve this from the relay, and without going near the tank itself. As a precaution, I would have a switch in the temporary supply, and be able to access it as the car is being cranked, and hopefully, running. Clearly this is not a permanent solution, but it could narrow down the search.

 

I'm leaning toward the crank position sensor. Seems to be the most common thing to cause misfire, eratic starting. Now to find it.....

 

Well, I found a thread outlining crank/no start on here. Seems my crank position sensor must be good, as the tach reads about 2-300 rpm while turning over. The car now only acts like its firing, but sounds out of time. Is there a way to check cam position sensor? It has fire and fuel, but seems its firing out of time.

 

I dont understand why it would start, run, then cut out if your camshaft position sensor was at fault.
However, a crude way to check would be to mark its current position, and then loosen the clamp bolt. Have an assistant crank the starter while you turn the camshaft position sensor, and see what happens. I suspect you will end up returning it to the original marked position, but you would have eliminated something else.

 

I wouldn't take the 200-300 reading as confirmation that the crank sensor is 'good' in all respects.

** Lack ** of the 200-300 rpm tach reading, however, is generally confirmation that the sensor is flat-out dead.

Cheers
DD

 

Re-reading your various posts, it seems as if the problem started 20 minutes after something. Is this correct, and was it refuelling?
I am wondering again whether your fuel supply is contaminated, although if the car starts cleanly and cuts out cleanly, then this theory should probably be sidelined.
Does the fuel pressure gauge you plumbed in show the fuel pressure dropping when the engine cuts out? Have you had a chance to try a continuous feed to the fuel pump?

 

The fuel pressure maintains good pressure throughout the attempts to start. The car has 11.6V during cranking, but immediately goes back to 12.4-12.6 as soon as it starts. It will start, as I read that the cam position sensor only gives it a reference for starting, then the crank position sensor takes over. I'm ruling out the battery. When I just kept on cranking, as in the other posts suggestion, the car does seem to overcome its reluctance to start at all, but once it does, its is very rough. Won't stay running.

Fuel pressure gauge I plumbed in shows a constant 40psi once the key is switched on, and during cranking, as well as eventual start.

As far as the twenty minute thing, the car has 3/4 tank of fuel. Ran great, even the last time it started and ran for 20 minutes. As I pulled away from a light, it began to misfire. Luckily, I made it back to my shop, where it completely died. Now, even if you get it to start, it doesn't have enough power to pull from its own spot, much less try and drive.

Thanks Doug, about the commenting on the crank position sensor. My Marelli experience tells me that those should read 680 ohm resistance. I haven't found a reference for that on this car. Also, I read where cam position sensors can be a problem, ARE a problem, but once the car cranks, it will run with it being bad. This car won't. Takes me back to the crank position sensor. Any and all comments appreciated.

 

As I recall one of the possible symptoms of a bad crank sensor is that the tach won't show the correct sub 1k RPM during cranking.

.

 

I am sitting here with the crank position (generator). It is showing 1.394 ohms of resistance. Anybody know what it should show? I don't mind spending money on my cars, but with so many of them, I like knowing I'm spending dollars correctly.

That is what I read too Al. The tach is showing 2-300 rpm during cranking, and the car is stumbling to run once it does start, at around 5-600 rpm. If I understand correctly, the ECU wouldn't show rpm if the crank position sensor is bad?

 

I second Doug about the crank sensor
worth changing anyway if it's the original...

 

As much as I have harped on the Marelli ones, I guess you are right. I know that the magnet loses its mag-nativity over time, and it appears to be the original. Its just that we have a drive coming up next weekend, and that front sensor doesn't seem to be available locally, and if that isn't it, well....

 

Greetings Gene,

What a saga... Poor fuel has been brought up, but it would be wise to clarify and rule out a fuel quality problem. Namely, fuel that is contaminated with water.

Where did you fuel up last? Is it a major name brand station or discount? Do you fill up there frequently? How long before your troubles began did you fill up?

If there were water bubbles in the station's fuel supply, if the supply tank was low, if water in the supply tank wasn't reported or duly removed, if water (rain or snow) got into the car's gas tank... You could have those exact symptoms... although your case seems severe.

I had a few temporary stalling episodes recently. A sudden stall usually while stopped or going slowly, followed by a difficult restart and poor running (and a tendency to stall again) for a few miles.

I finally came up with a connection (after a casual suggestion from my non-car Better Half) to when and where I refueled, and when the stalls occurred. I found that I had been occasionally fueling at a particular discount station, 2 or 3 days before the sudden stalls happened. Once I started always fueling at a major name station, I had no further problems! Coincidence? I think not.

Water bubbles in the fuel tank will coagulate over time to form larger bubbles at the bottom of the tank. They will eventually get sucked up by the fuel pump. It seems like when this happens, the fuel pump and filter will tend to break up the water bubble and cause stalling and very poor running while the bubbles are in the fuel line and rail.

For lack of your discovery of any other obvious problems, as was the case for me, I offer this two cents. Best of luck!

 

Superchargedtr6,
having read your latest description of the problem, I would like to reinstate my fuel contamination theory!
Water contamination could well be the culprit.

 

Not sure how to rule out fuel contamination, but I have ordered a crank position (generator). It is supposed to be here tomorrow. I am not a aircraft mechanic, but from what I have read, the magnetos have to be changed every 2000 hours due to the magnets losing there ability to generate a field. These sensors(?) are small AC generators.

I still am having a hard time with thinking its contaminated fuel. I filled the car up at the same big name station I always fill up at. I drove it almost 1/4 tank, say 60-100 miles. Then I drove it on the last day it ran well for about 20 minutes when it suddenly began to run poorly, and eventually quitting altogether.

I will post results.

 

Put a new crank sensor on it, and it fired right up. Runs as good as ever.....but....the dash has lit up. Now, not only is the check engine light still on, showing same codes, it also says trac lock fail, abs light is on, and the trac off light is lit up. I did take the battery out, and charged it, so the car was dead for a day or two, but looks like typical Jaguar. Fix one thing, two more go wrong.....sheesh