Only the 4.2 liter V8’s are a returnless fuel system. All the X308’s have a fuel return line. You cannot view system fuel pressure with a scanner on our cars.

The open loop is because the coolant temperature isn’t high enough to go to closed loop because the engine isn’t running.

 

If there is low fuel pressure at the engine rail, try replacing the fuel filter to see if the pressure returns to normal. If not, the PCM is not receiving a signal from the CKP or the fuel pump is failing.

I don't have an X308 handy at the moment, but I can check the fuel pressure via the OBD port on my X200, which is the same 4.0 litre unit fitted to the X308.

 

It’s been a long time since I’ve worked on a 00’-02’ S-Type 4.0 V8. The only thing I remember between the X200 & X308 4.0 is the intake manifold along with the TB is completely different. NBC, if you have a fuel pressure sensor on your intake manifold, that would explain why you can read pressure on a scanner. X308’s never could regardless of N/A or S/C.

 

Happy New Year!

Well, after the miserable week of being sick... new fuel filter is in. The pressure in the rail went up well into 30s(I am using cheap tire gauge). But the same thing, car does not want to start. It sounds whiny. I do get occasional fire in a cylinder, but that's it...
I am still puzzled why so sudden... Are there any vacuum lines running to ECU (I know my XJS will die if such line gets broken), anything else that can break and would not get reported by OBD?

 

Sounds whinny?? That would be bore wash then. Assuming the battery is in good shape, the engine turns over really fast then. If that’s the scenario, keep a good charge on the battery, gas pedal to the floor (keep it there) and crank the engine over for about 10-15 seconds. Turn key off for 15 seconds, gas pedal to the floor and crank it for 15 seconds. Do this for about 5 cycles (or more) then foot OFF the gas pedal and crank it over. It should at least pop and fart a little bit as fuel pressure builds back up in the fuel rail. Be very patient with this. If after 15 or so seconds of trying to start and it doesn’t run, turn key off and let the starter rest for a moment. This might take several tries. The idea is to introduce heat into the piston rings so they’ll seal against the cylinders.

 

I have no feel if engine turns too fast, I can't see from inside and have no one to help. Will spaying starter fluid into throttle body be of any help? Or a cup of fresh gas? It does crank kinda too smooth...

or maybe pulling the plugs and putting some oil into the cylinders?


Now that it's been a few weeks I can't remember if I filled the gas tank that day on some shady gas station(I have 3/4 of a tank). The bad gas theory does not sound too far from reality now... but it will be a pain to syphon and put somewhere 3/4 of a tank...

 

A squirt or two of oil into each cylinder is one way to get your compression up.
However, the suggestion by AddictedtoBoost is more convenient.

 

Yes, and today was the squirt day... I figured I don't want to leave it to chances, so I put a little bit of oil in every cylinder and while at it I checked that I have a spark..


My Christmas lights this year, kinda liked them :-)

But at the end - no luck. I also tried long attempts with throttle pressed in... yes, there were few farts, but that's it.

There is a humming/buzzing coming from throttle body, which I guess is a warning that TB may fail, but as far as I see it is working as it should.

With sparks sparkling and throttle opening I blame no-start on fuel part of things... How can I check that injectors are injecting(i will search, just not now)? Because if they are - syphon/replace fuel will be next.

 

I had this same no-start experience after I had the valve covers off and tensioner replaced. The car had been stationary for months. When I had the engine buttoned up again, it tried to fire once, and stubbornly refused thereafter. I tried it every morning for one decent attempt, and it finally fired on day 6 or 7. Been on the road ever since. I guessed it to be a drained fuel system and injectors that needed to be refilled before pressure was sufficient.

 

Wow. Thank you for sharing. I will keep trying.... this morning I was checking if my crankshaft position sensor works and car did few extra coughs... I can't imagine injectors needing time to refill, but totally understand gas being crappy. I am thinking to add something like "stabil start" to tank before trying to replace gas.

 

So ...if the fuel in the lines drains back to the tank thus needing many cranks to reach the injectors
and build pressure, wouldn't that indicate a leak in the lines between the pump and the injector?

 

Why not shoot a bit of starting fluid in the breather? If it is bore wash then getting the engine to start usually solves all that?
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A backfire could crack the manifold.

 

Sun is shining again and I want to bring conclusion to this confusing thread...

Today at lunch break I made another attempt to start the car and to my surprise after another long attempt car started! Big stinky white cloud marks my house on the street...
Before starting car I did empty one of those "STA-BIL Start Your Engines" cans into tank. Not sure how much it helped because one can is supposed to treat just one gallon of gas, and I have 3/4 of a tank...

First of all many thanks to everyone who helped. Addicted2boost you were right all the way, replace tensioners and reevaluate was the right approach. Bore wash it is.

To anyone - if you still have those plastic secondary tensioners - replace them now. Replacement parts are chip, work is manageable(zip-tie method was easy). Doing so will eliminate this fear of attempting to start the car when it dies/shakes/farts due to an unknown problem.

Cheers!

 

All,
Car: 2000 XJ8, 4.0l, 60,000 miles, good maintenance. I performed preventive maintenance by replacing the secondary tensioners via the exhaust sprocket removal process as specified by the JTIS (Jag maintenance instructions). I had all four flat parts of the cams (referred to as "flats," the part of each camshaft that is on the very front of the camshaft, that is indeed flat) aligned and installed the camshaft locking tool and did not move anything. However, I did not install the crankshaft plug but did not move the crankshaft at all during the process since it was difficult and I was working alone. Everything went well on start up, and subsequently, but I now have a slightly rougher idle. Question: Did I "F" up by not inserting the crank plug or is this normal after a secondary tensioner replacement? Did I jump a link in the timing chain? Should I take a Mulligan and redo the job? I don't understand the purpose of the crankshaft plug if you don't move the crankshaft and the cam locks are in place.
Havala,

James

 

The purpose of the crankshaft locking tool is to keep the crankshaft at the correct position so the cams are timed correctly at 45 degrees ATDC.

 

Thanks CAT! So in this case even though I had the cam locks on and all four cams perfectly flat (at least to the naked eye) but the crankshaft plug was not in and I could see that the elongated hole on the flywheel was not perfectly aligned, I should just bite the bullet and redo the job? Will simply loosening, retensioning, and torquing the camshaft exhaust sprokets along with installing the camshagt locks and crank plug be the likely remedy? My thought at the time was that the cams were flat and locked, it was getting late...ect, so I was good to go. My conditions post secondary tensioner change now are a slightly rough idle and somewhat noisy valves. You think its now slightly out of time? Again, thanks!

 

With only changing the secondary tensioners you only did half the job? What condition are the primary tensioners and the chain itself in?
If you jumped a tooth it should have set a code but you will need a good scanner like the factory SDD to see most of those types of codes.
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Club,
Thanks! I did find cracks in the secondary tensioners.
My evaluation to just change the secondary tensioners was based on these observations:
- the chains do not appear to have stretched and are clean and tight
- I don't see evidence of unusual wear patterns on the sprockets and guides or any noise from the chains (used a bore scope)
- the engine is clean inside (little varnish) with no evidence of wear on the timing gear
- The car has 60,000 miles and appears to have been fairly well maintained

Doing the whole kit would be a big job for me and having no previous experience with Jags I don't know the various unpublished techniques and I also don't want to blunder into the unpublished pitfalls of this job. I don't rule out doing the complete job in the near future. What am I missing? Thanks again!!

 

Remove both cam covers and rotate the engine in a clock direction only when viewed from the front. Use the 24mm crankshaft bolt to make at least four complete revolutions of the engine and reinspect the position of the camshaft alignment 'flats' to see if the exhaust cams are still in the correct position in relation to the inlet cams.