Maybe our octane boosters are better down here. In the past i've seen more timing advance (on the torque app) after adding octane booster to the fuel.

Yes my priority now is to get the remaining fuel out of the car, but that's not as easy as it sounds. See below.

Problem is there are no low-point drains on the tank. My syphon hose won't go down the filler neck. There is no schrader valve on the fuel rail in fact I can't even see the fuel rails because they appear to be under the charge coolers.

How awesome is this:

JTIS says that to remove the fuel rail, first remove the fuel injectors. Check the fuel injector removal instruction, it says to first remove the charge coolers. Check the charge coolers removal instruction, says to first remove the supercharger. No need to check the instruction to remove the supercharger, because we know that's a 9 hour job...

As for draining the tank, the only points you can actually syphon fuel out of the car are at the in-tank fuel pumps accessible under the back seat or at the fuel filter which is behind a panel under the car below the front passenger seat, but apparently you can't drain the tank from where the filter is. The dealer drained the lines only, from either side of the fuel filter. You can't drain the tank from the lines at the filter, you only get out what's in the lines. So they tell me

I shook up the can, poured it into a glass jar with a sealed lid, and let it sit, nothing to see except clear yellow fuel. Nothing floating at the top or settling at the bottom.

The only fuel with ethanol is E10 which is typically a 91 with 10% ethanol. The other fuel grades of 98, 95 & 91 have no ethanol. If fuel has ethanol in it here has to be marked accordingly.

 

Would it be worth removing the back seat to at least see if you can assess how the fuel pumps sound when they run, and if you decide the pumps are fine, then lift each pump and siphon the fuel out of its side of the tank? In the EPC it looks like the pumps are just secured by retaining rings that twist off.

 

Yeah that might be a start. I honestly don't have the enthusiasm to pull the car apart right now, i've got a 2-1/2 week business trip coming up, leaving on Thursday. Half tempted to park it up & not bother till I get back.

There is a special tool to undo the nuts, Bosch want £200 for them LOL...



But there is a home-made version which will work Tool for removing s-type fuel pumps

34by151 reckons he got his off by tapping it with a hammer & punch. The locking rings are fairly cheap as spares anyhow...

See how I go tomorrow...

 

I recently replaced a fuel lump on a ford. I rented a universal tool from the local autoparts store to remove the lock ring. Maybe this tool may fit. I did try a rubber mallet first but to no avail. Hope this helps.

 

As long as you alternate your taps around the entire ring I would expect that to work. The retaining ring in our BMW is similar, with raised "ridges" on the top surface, and the drift punch/hammer method worked fine (lots of light taps always moving to a different ridge for each tap).

 

If the car is running ok as long as you stay off the deep end, the best bet might
be copious amounts of gas drier/antifreeze. This mixes with the water and the
mix then gets burned. If you drive easy until the end of the tank, you can avoid
the detonation.

If you then run to almost empty, and use the same routine on the next tank,
you ought to be good to go.

Certainly worth considering as it's much easier than taking things apart.

++

 

I have been addingTC-W3 outboard oil 1.9 ml per litre to all my 4 stroke vehicles for this reason to remove moisture from the fuel system
You could try filling a jerry can with fresh fuel and add a bottle of methylated spirits then just drive it do this a few times nearly running the car empty each time then maybe a new fuel filter when the car comes back to life
I am lazy to
I did that to my ex wifes 190 e many years ago when it had a similar problem took about a week just kept adding metho at each fill up till it cleaned out the water

 

You're still at that? I must admit that I missed the last few tanks and have just started again.
Mind you, the way I splash it in is not nearly so precise.

I don't know that it absorbs moisture, for a specific moisture problem like Cam's I would go
for the HEET or similar.

 

As time passes i'm more & more convinced that it's not water in the fuel, it's just crappy fuel...

Will go to a Shell & top it up with 98, see what happens.

 

Now this is interesting http://porscheforum.com.au/index.php...n-bp-ultimate/

I distinctly remember it was really, really slow to fill, i was thinking to myself "why is this taking so long?" and that's one of the reasons I only put in 30L instead of brimming it.

99% sure it's just crappy fuel.

 

We'll be curious to hear how the car does with the addition of the good Shell 98. Once you burn through the crappy fuel mix, it might be a good idea to replace the fuel filter again.

 

Well at least they can discuss octane without getting all pissy about it.

 

Crappy fuel is more likely
I filled up in Qld to head down to Melb got my worst mileage ever on the van

It's a diesel got 894 k,s to 79.6 litres bp ultimate diesel

Filled up in campletown this time using Caltex vortex diesel immediately getting good economy again got to Melb stil got quarter of a tank used 11.1 litres per hundred from Gold Coast to Sydney normally get 7.9 litres per hundred I'll know exactly tomorrow when I fill up
The funny thing you said BP and I just filled up with bp normally is use Caltex vortex diesel as I get 100 k,s extra is per tank in the van and the wife's diese jeep

Thought I would try the bp ultimate diesel got really bad economy

And yes plums I still do the TC-W3 religiously with all my vehicles 4 stroke and diesel

 

Okay filled up again today got 1051 k.s for 78.9 litres fuel
So the theory of bad natch of fuel is possible

 

Well, seems that it's not the actual fuel that's causing the hesitating & detonation...

This morning I pulled the #1 plug to have a look (well for others to look, I don't really know how to read plugs)





Thats a Denso Iridium after 21'000kms / 13'000mi, as opposed to new



Doesn't look like any erosion...

I also cleaned the MAF, nothing came off it. When I first cleaned it a while back a lot of yellow/brown residue came off it, this time nothing. I last cleaned it about 6000kms / 3800mi ago, I think.

I cleared out all the codes, nothing came back straight away.

Then I pulled out the back seat and tried to listen to the fuel pumps. Very hard to hear them running because of the exhaust but with a screwdriver to my ear, yes both sides sounded the same.

I disconnected one of them (right side, A) just to see what happens, car throws up restricted performance & a code for fuel pump open circuit. Given that I never had any codes or restricted performance from this problem, that can rule out any wiring issues...

Leaves me with bad fuel, bad pumps or possibly a blocked fuel filter.

So I put in 20L of Sunoco GT 260 Plus (110RON, 104AKI) to rule out "bad fuel"



It's still pinging & hesitant...it's not bad fuel...

Went for a drive with the IDS/SDD as a datalogger and monitored the fuel pressure via the sensor at the rail, cruising around it was pretty much 55psi. Full throttle from about 4000rpm the pressure climbs up to ~70psi, from 5000rpm it drops off to ~60-63psi as it starts pinging & hesitating...

I was under the impression that these things were 55psi all the time, so I don't know if seeing it go up to 70psi is normal (i guess so) but the drop off in fuel pressure at the same time as it hesitating / pinging can't be a coincidence...

Can't rule out a blocked fuel filter, even though it was changed 21'000kms / 13'000mi ago (the normal service schedule is every 96'000kms / 60'000mi) but I guess i'm up for new fuel pumps.

 

I'm no expert at reading plugs either, but if the deposits on the plug look like sooty carbon, that's usually an indicator of an overrich AFR, which would make suspects of everything to do with fuel mixture, like the air filter, ECTS, MAFS/IATS, O2 sensors, MAP sensor, Intercooler Air Temp sensor, ECM... I'd tend to suspect the ECTS first, and the MAFS/IATS second, but don't ask me to defend that statement.

I don't think the X350 has a fuel pressure regulator that can leak unmetered fuel into the intake manifold...

A stuck-open purge valve could allow unmetered fuel vapors into the intake but I assume the resulting enrichment would be relatively insignificant.

Another possibility (at least in the old days) would be weak ignition voltage, but I'm not sure that's true on COP systems.

I guess another possibility is incorrect plug temperature. Were your original plugs NGK Laser Iridiums?

 

On an OBD meter (or SDD) it should read 55psi at all times. The sensor has a manifold reference and the system varies the pump speed to hold a 55psi differential against he manifold pressure, either vacuum or boost.

If you use an external gauge you will see 55psi + manifold pressure, so something in the range of 40-70.

I have no direct experience with an XJR but I have done some fiddling with the pressure in the 4.2 XKR.

My guess would be that you have a bad sensor. Located on the right side fuel pressure rail near the front. Held on by 2 bolts, easy to access without removing anything else from the car.

My reasons:
70psi is not a high enough pressure to cause the injector not to open, so pressure too high and fuel starvation don't make much sense together.

You got an error that is pump PWM too low, meaning that it could run slow enough to get back down to 55psi. This should not be a problem, unless the sensor is lying and says the pressure is higher than it actually is.

What to check:
Fuel pressure with an external gauge. This one can be difficult. Most cars any more don't have the handy dandy schrader valve to just hook up a gauge so you might need to invent something.

Fuel trims at idle. Are they way high as if it's compensating for low fuel pressure?

Pump PWM drive. This should range from about 20% at idle to near 50% at 6000rpm. If the drive output is much less than 50% at WOT, then that is likely the reason for fuel starvation.

The raw O2 sensor output. The stock sensor is actually a wideband O2, and there is a lot of useful data in there, if you know where to look. You can't see fuel trims at WOT but you can log the raw O2 ouptut in mA and convert that to AFR. If there is a lean condition, you'll see it.

 

Charlie,

Does Cambo's spark plug look like his engine is running lean?

 

That's not a lean condition. Oil fouling and fuel fouling can look very similar, but this looks more like fuel fouling being that it's dryish. I'd consider looking at all the plugs as the next step.

 

Couldn't say, have never read a plug in my life.

How would this explain the rattling or the erratic fuel system behavior?