Flooded

[RichardSEL]

Went out at 1pm into the fresh warm sunshine and Ludlow wouldn't start. Didn't do anymore then
Went out at 3pm into the continueing warm sunshine and again wouldn't start. Removed air elbow to throttle body
cleaned as far as possible the butterfly and chamber with switch cleaner (Servisol)

Removed MAF both temperature and flow sensor areas were grey. Sprayed them with Servisol and left to soak in
Good how to for both as a .pdf file at:
http://www.mediafire.com/file/43rs029k5 ... n_MAFS.pdf

Put it all back together, instant start. Left in idle (idle revs a bit fluctuating but as temperature rose revs settled down. Switched off at half the normal temperature range. Ludlow wouldn't start again (4.45pm). MAF had it?

[RichardSEL]

5.45pm -- tried start again, still some nice autumn sunshine. A weak single or two cylinder fire then nothing.
Took MAF out and sprayed with Servisol yet again. Tried start with MAF out but still connected. A better start but then dies. Put MAF back engine starts as if nothing's wrong. Left to tickover up to normal temperature. Switch off. Immediate start. Left for 30 secs no start.

Flumoxxed!

[RichardSEL]

8.25am -- just tried to start again in the chill of the morning -- no start, not even a weak misfire start.
Will explore changing the MAF first as I can get to that easy in the street.
Unless anyone else here tells me I should be doing something else?

[RichardSEL]

Changed the MAF for another used but known good. Still no start. Tried Easy Start into the MAF hole and got start and die. Tried Easy Start into Throttle Body butterfly and got start and die. Local Jag guru suggest either I have a faulty (intermittent) fuel pump or there's water in the fuel that some of these XJ8 are known to allow via the filler flap breather

Havn't yet checked the fuel pump fuse -- but water in fuel could sound plausible as guru added that water is heavier than petrol thus settles at bottom of tank. Overnight can get sucked into the fuel system first. That's got some credance as there was heavy rains here the two days preceeding this first non-start

Whichever, said guru suggested opening the "Schrader valve" that's adjacent to the "short breather hose" to see whether there's fuel coming out there and if so does it smell like fuel? And then had to run off the 'phone. He had previously said that the start and die I had got when spraying the MAF with Servisol would've been the Servisol acting as Easy Start, not me cleaning the MAF's elements

Could someone guide me to where this Schrader valve is? Not knowing what I'm looking for doesn't help

<later> similar thread for XK8 but doesn't say where this Schrader valve is:
viewtopic.php?f=68&t=10137&p=53405&hili ... lve#p53405

[Andy P]

Hi Richard,
Really feel for you mate,nothing worse than an intermittent problem and you can't find the reason why .
I'm afraid it might be a case of checking the basics which can be time consuming and in the end it's not the cause of the problem anyway .
Battery Condition.
Spark Plugs.
Coil Packs.
All the power connections.
Earthing connections.
Fuel Pump and Pressure.
Injectors.
TB and the MAF which you are looking at already but I've also found out the crankshaft position sensor can be troublesome and cause hard/no starting issues and you will not usually get any codes for CKPS failure,also they appear to die when cooling down.
Hope some of that helps,if I think of anything else I'll let you know.
Keep us updated on your progress,
Good luck,
Andy

[Andy P]

Hi Richard,
The fuel pressure regulator is at the rear of 'B' bank tucked down to the left hand side of throttle body.
The schrader valve is on the fuel rail.

Fuel Pressure Regulator

Schrader Valve

You should have 41 psi at the schrader valve at idle.
Good luck
Andy

[RichardSEL]

Battery Condition.

Getting good spin still from this 120AHC battery (but dunno how old it is)
At least we're still in some late sunshine

Spark Plugs.

Changed 6,000 miles ago

Coil Packs.

Never been changed as far as I can see. But when I did get it running in the supermarket car park on Sunday there was just the occasional misfire that eventually went away

All the power connections.

It fires and dies that's what's so weird. I've got another second hand throttle body but there's too many connections for me to change out kerbside -- and I don't have the range of tools I once had

Earthing connections.

Ditto

Fuel Pump and Pressure.

This could be suspect. I found the Schrader valve. Mine was under a blue screw off plastic cover. But doesn't look like the one in this pic (location's the same though)
With the IGN on, there's a dribble of fuel out of this valve when the centre pin is pressed. It smells like fuel alright. But it's only a dribble

Schrader valve location xj8 '99MY

Injectors.

Have heard of them go, but like plugs, not all of them at the same time -- unless a serious loom melt

TB and the MAF which you are looking at already but I've also found out the crankshaft position sensor can be troublesome and cause hard/no starting issues and you will not usually get any codes for CKPS failure,also they appear to die when cooling down.

Where is this, how can it be changed. Kerbside?

Hope some of that helps,if I think of anything else I'll let you know.
Keep us updated on your progress,
Good luck, Andy

Most useful -- keep the thoughts coming

[davidr]

That is a picture of the fuel pressure regulator. A Schrader valve is like a tyre valve and is on the fuel rail (left hand I think). Plug a fuel pressure gauge into that.

[Andy P]

That is a picture of the fuel pressure regulator

Hi David,thanks for correcting me,you are quite right that is the fuel pressure regulator not the Schrader Valve
as I had thought .
Richard,
If you've only got a dribble of fuel coming out it could either be the fuel pump or fuel pressure regulator,lets hope it's the latter.
The CKPS is on the back of the bell housing,access from under the car I'm afraid.
Good luck.
Andy

[Andy P]

Hi Richard,
Might also be worth having a look at the fuel filter,that often gets overlooked when servicing due to the awkwardness of changing them.
As always good luck.
Andy

[Andy P]

Hi Richard,
Here is the correct way to test the fuel pressure.
Taken from the X308 Workshop Manual page 1689.

1. Make sure the vehicle is in Park.
2. Apply the parking brake.
3. Place suitable absorbent material around the schrader valve to
absorb any spillage when connecting the gauge set.
4. Remove the protective cap from the schrader valve.
5. Connect the gauge, using adaptors if required.
6. Remove the absorbent material and dispose of safely.
7. Disconnect and plug the vacuum hose from the pressure
regulator.
8. Start the engine and record the fuel pressure reading.
 As a guide, the fuel pressure should be approximately 3.0
bar (44.1 psi) with the regulator disconnected.
9. With the engine still running, reconnect the vacuum hose to
the pressure regulator and record the reading.
 The pressure should drop to approximately 2.6 bar (38
psi) when the vacuum hose is reconnected.
10. Switch off the engine.
11. Place more absorbent material around the schrader valve.
12. Where fitted, open the drain valve and allow the fuel from the
gauge and line to flow into the container to depressurize the
system.
13. Disconnect and remove the gauge set and any adaptors.
14. Clean up any fuel which may have been spilt and remove the
absorbent material. Dispose of safely.
15. Refit and secure the protective cap to the schrader valve.
16. Reconnect the fuel pressure regulator vacuum hose.
17. Start the engine and make sure there are no leaks.

Hope your making some headway my friend.
Good Luck.
Andy

[RichardSEL]

Got myself a tyre valve removal tool and loosened off the Schrader valve innards
Guru said that I should get a pulse of fuel when starting that can be seen from driving position i.e. a squirt about 18" up from the Schrader. Nothing apart from a dribble. That indicated to him on the 'phone that fuel pump had had it.

Said Jag guru had a cancellation so he popped over (12 miles round south circular -- rush hour just starting) in his pick up. By that time I'd checked the lower line of fuses in the boot fuse panel and none appeared open circuit. That would've covered the fuel pump fuse. Tried tapping the block relays but said guru turned up saying most likely pump gone which is inboard to the fuel tank. Loaded up and carted off.

Not too sure where fuel filter is. Can see the pressure regulator. Those pics are very welcome! This chap does some work for other shops when they're stuck too. And I've never caught him "trying it on". Coz at his time of life he doesn't need to. So trust that he'll eliminate filter and pressure regulator first. He's got an XJ8 3.2L in his pile of squashed cars so OK for second hand parts.

Will report back as soon as I know
(Andy, dunno what the fuel PSI should be at cold start up but that dribble sure wasn't 44psi )

[Andy P]

Hi Richard,
Thanks for the update,sounds like Ludlow is in good hands.
The fuel filter is located above the rear axle on the near side of the car,tricky to get your spanners up there.

Location of fuel filter

Which is why it gets left I suppose.
Good luck with the Guru and hopefully a speedy return .
Take care.
Andy

[RichardSEL]

Said guru's just 'phoned to say fuel pump has had it. I asked whether he'd replaced from his pile. He said no, so it's in with a new one £70 ex-Brit Parts -- comes with new filter too.
It's the labour charge as it's a tank out, thus sub-frame down job. Still musn't grumble. I know he'd do it correctly. Lucky to have bought Ludlow at a silly price originally.
So what with the prop shaft carrier bearing, NSR hub, and other odds & sods I'm no worse off against buying at the correct price initially. Except I would'nt have bought at all

[RichardSEL]

Been doing some run abouts since picking Ludlow up -- the start up's so much faster now with new fuel pump and new fuel filter in. He showed me the old filter like a white plastic bag with some rust bits in it. He said it shouldn't have been nearly flat. The startup's even faster than I remember the Sport's -- just a part rev and immediate firing.

Guru said that the response on the road is much better too as they'd got it to fire start eventually by using Quick Start but, like I found in the supermarket car park, it would'nt start again after five minutes or so. So I assumed there were two petrol paths: one for choke start, the other for normal running when up to temperature. I was wrong.
Still not too sure what the choke operation is: injector pulse length or air flow restriction? Combination of both?

F7 Fuel Pump 20A, F15 s/c Fuel Pump 20A

Whatever's an "s/c fuel pump"?