David I had something similar on my 4.2 and it turned out to be a pressure sensor that had an intermittent fault we found it by chance

Cheers Sandy.

I had to remove the MAP sensors to send the Supercharger away for rebuilding, you can’t buy the o-rings on these so I refitted them with the old ones. I’m wondering if it could be something as simple as them leaking.

Will see what I can find.

David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

I recently had this on my 4.2 stuttering under high load conditions such as climbing a hill with a heavy load or full throttle in a high gear, even stuttered enough to go into limp mode but with no fault codes showing on the IID. Fine in all other conditions though, even hard acceleration if the load was not too high.

I suspected a coil so on the IID I loaded the live missfire values, all were zero in normal driving but if I manually selected a high gear and used heavy throttle the stutter started and the missfire counter for cyl #4 shot up to 70. I repeated this a few times and every time it was the one cylinder so I swapped the coils on cyls #4 and #2. Went out for another drive, repeated the test and sure enough, #2 was now stuttering so it's a faulty coil.

In all other tests the coil is fine, but failing under load. Annoyingly all 8 coils were replaced by the PO not that long ago and this is the 2nd one that has failed, they were sold as Lucus too. I'm replacing them with NGK now.


EDIT: Sorry I've just seen you aren't showing any missfires, so possibly not the same issue. NB. mine only showed missfires on the live values, not stored. 2006 L322 Vogue SE 4.2

I’ve not driven the L322 for about a fortnight now so I took it for a run tonight. It was meant to be booked into the local specialist for a high pressure smoke test today but due to a tech having a family emergency they had to cancel and rebook.

I’ve taken a lot of readings with the IID tool.

The airflow readings are not far apart from each other. I don’t know if they’re far enough away to be causing issues though.

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After a bit more reading this morning, I’m convinced it’s the MAF sensors. I could be wrong, but there’s my logic…

I read a thread on Jaguarforums.com where someone was troubleshooting a rough idle on an F Type R. He posted this:

“MAF readouts show exact figures on both sides so I assume they are both fine then.”

Looking at mine, I initially thought they were similar but they’re actually 2100g (2.1kg) of air apart.

Bank 1 reads 70560g/hr whereas bank 2 reads 68400g/hr.

If the ECU thinks Bank 2 isn’t getting the air it should then it’s probably going to think Bank 2 is running rich. Bank 2 is the one that’s getting a negative fuel trim.

I’m going to order a pair of Denso MAF sensors and will fit them and the oxygen sensors I’ve got over the next few days and see what’s what.

David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

Does the fuel pressure rise when you switch the engine off?

When my HPFPs were shot I had the same hesitation and generally rising fuel trims, a sure way to tell is pressure dropping at engine off rather than rising.

Thanks for the suggestion.

I’ve got a blanking plate on order that lives on the back of the supercharger which due to LR moving warehouses I’ve been told will take approximately a week to arrive.

I’ll check the fuel pressure when I can start it again. Did you find your oil level was increasing when your pumps were leaking past? The one thing that made me discount them as being the cause was both of your fuel trims were negative whereas only one of mine is. It’s also stationary at -12.5 and isn’t getting far enough to put the EML on.

I take it the IID tool will monitor fuel pressure at shut down and not just loose comms when you switch the car off?

Thanks,
David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

My oil level did increase but it took its time to show on the digital gauge, it was most notable when doing the actual oil change.

The IID will continue to monitor for at least 5 minutes (that's only as long as I needed).

Fair point regarding the trims, the injector values look ok as well and that's an expensive and long winded route to go down on a whim!

Hope you get to the bottom of it, car is looking great!

I’ve done 100 miles in the car today and can report the following:

After replacing both MAP sensors, both oxygen sensors, both MAF’s and both air filters the fuel trims appear to be much more in sync with each other.

When switching off the car, the fuel pressure does increase gradually over a period of time.

After the most recent spate of work, the car feels smoother and sounds happier when sitting on the motorway on cruise.

However, the hesitation is still there. It only seems to occur when under load at low RPM. It’s more noticeable when accelerating gently in 3rd gear from 1500 - 1800rpm.

It feels like a misfire, however, the IID is logging zero catalyst damaging, or emissions related misfires. I monitored them over 15 miles on the motorway and when climbing a hill whilst the hesitation was obviously occurring.

Back to the drawing board by the looks of it.

David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

I’m wondering if I’ve been going about this the wrong way…

When I can feel the hesitation/stutter, there are no misfires or anything being logged. At all other times the engine feels amazingly smooth and powerful.

I’m wondering if it could be transmission judder that I’m feeling. I’m going to go for a drive with my IID tool connected shortly and see if there’s anything untoward when monitoring the speed sensors in the gearbox. If the torque converter is causing it then I’m half expecting to see the hesitation mapped in a graph of the speed sensor reading.

Will report back later on. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

Ok, it looks like it’s not something that’s gearbox related. You can see on the attached video that whilst the engine revs are fluctuating the gearbox input speeds are rock solid.



Before we headed the 100 miles home earlier this morning I reset the engine adaptions as I’d forgotten on Friday before we left. I had a look at those tonight.

Here’s the fuel trims from before I replaced all the sensors:

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Needle in a haystack springs to mind!
You will find this………………………  2014 vogue se