Hello, I recently purchased the Jag, who had been sitting for 10+ years, only 100k Km since new. After purchase, spark plugs were replaced, oil and oil filter, air filter, gearbox fluid changed, secondary tensioners replaced basically. Today it was my first proper test drive as weather allowed.

The car has always idled fine at 750 rpm, no gearbox clunk noise when changing (just one slight one when car was really cold) but to be honest, I don't feel it very powerful, as if it needs some help on the gas to reach highway speeds, but other than that car revs fine, at 120 kph it shows around 12l consumption and looks to keep pace with traffic once speed reached, so everything looks relatively fine...but to my surprise, two times when I was joining the highway and revving in sport mode above 4000-4200 rpm, the car car starts behaving oddly, as if it was bouncing forth and back or the engine was stopping-accelerating constantly.

Car does not shows any error code (on the dash) and other than that, it works fine I believe.

Could anybody help with the topic?

I also feel a little bit of a dead zone in the direction at the very beginning of the steering wheel turn, but right now that looks secondary....

Thanks.

 

With your list of things done to a car that's sat that long, I think I'd go for a fuel filter next. It's a simple enough thing to do & might solve it. There's probably a load of crap settled in the tank after that long if you hadn't flushed it out.

 

Yes, I forgot to mention, fuel filter was replaced as well.

 

What type of fluid did they put into gearbox? if it feels like pulling strong then somehow much weaker then strong again then weaker and so on it may be bad torque converter, worn torque converter clutch valve in valve body, gearbox fluid pressure leaking somewhere like in cracked top valve block, wrong type or wrong amount of fluid
But before you start digging into gearbox check the fuel trims and fuel pressure under load

 

Hi, I would not describe it as pulling strong then weaker, but rather pulling/stopping, a feeling that was a bit scary. Although I only really felt it once before releasing the gas, so it is not something I can describe precisely.

Mechanic put Mobil ATF LT 71141, he said he had to struggle to find the one that was inside the gearbox...

Excuse my ignorance, how could I check fuel pressure and fuel trim?

Thanks.

 

For fuel trims you need OBD2 reader, either a dedicated tool or just BT dongle which you plug into diagnostic terminal and connect to your mobile with app of your choice (torque for example), cheap and useful stuff, you will need it from time to time to read codes and stuff
For fuel pressure you need a gauge, there is little valve in fuel line on the front of the engine it is where you hang the gauge
Did the engine feel like still running (but not pulling) in the moment of "stopping" or just cut off and then came back?

 

I wouldn't know what to say...the only thing I remember is that it appeared slightly gentle and then I tried to keep revving to see if I overcome that feeling, but the more I pushed the worst it seemed to get, a lot of jerkiness, so I released the pedal...

I will start with the measurements and report...will not probably be too fast though. Should I go down the way of cleaning MAF, throttle body, maybe adding some injector cleaning to the fuel, or is it nothing related?

 

I had very similar problems, which working through this list fixed, although cleaning the MAF first worked. Cleaning the TB was just icing on the cake.

Good luck
Peter

 

Keeping all that stuff clean is a right thing to do anyway so of course go for it, and definitely get an OBD reader so you will have a chance to see how various stuff operates, if there are any pending codes that didn't trigger CEL
And keep observing, maybe it was just one time hiccup

 

Thanks for the tips, I'll get to work, although with a 18 months old at home and the car as a hobby I will not report black very fast I fear.

Now I miss the days of fixing easy **** like aerials and radio codes.

 

Clean the MAF; clean the throttle body and plate; with ignition off move gas pedal back and forth to clean TPS; put a can of fuel system cleaner in gas tank (Gamout, Sea Foam, Lucas' best), run the old gas to empty then new high test, check all wires to the spark plugs; if that doesn't work, recheck the timing (secondary tensioners).

 

Is the car an xjr? If so the second fuel pump may not be working

 

No, it is a 3.2 (this one was not sold in the US).

I ordered Techron fuel injector cleaner, should arrive this week. If this does not sort anything out, I will order the OBD reader (will do anyway, just need to decide which one).

Today I took a spare day and took the car with the wife inside the city. Lovely car, I mean, how often do I need to be stumping on the pedal above 4k rpm?

 

You need to stomp it daily, otherwise he will think you don't love him anymore and start behaving like a grumpy elder
Apart of that, unless it was isolated case, there is some underlying condition you wanna at least find out and most probably also fix, such a little thing as leaking injector may leave you stranded in most unfortunate moment.
Generally ordinary BT dongle and apk is cheapest and probably best way to go, dedicated scanner have sense if you get one that reads not only P codes but just all of them, sooner or later you gonna need it, you will find plenty of threads on scanner options here

 

With the age of the car and it's history of sitting for a long time I would suspect the fuel pump. It's so old now I would just go a head and replace it.
If it's not bad now it will be!
.
.
.

 

I'm just a bit reluctant as most advertisements say it is compatible 2001 onwards and mine is a 1998.

 

Maybe post links to those you are looking at, we may be able to confirm if they work or not

 

xjack if your looking for a scanner for your car have you looked at this permanent sticky thread? It is large but things change all the time with scanners.
Jaguar Scanners

I always use and recommend the very cheap Torque Pro. It's only about $5 if you don't get a free version somewhere. I use the OBDLINK MX+ OBD dongle.
If you post on the scanner thread maybe someone with your model of car can recommend one or more. I have ended up with a small collection of readers/scanners/programmers over the years. It just seems inevitable!

Finally moved up to a working SDD system. But I pull out the quick and simple readers first.
.
.
.

 

It's most likely the fuel pump as clubairth1 suggested. They can work fine
for low fuel demand then not enough fuel delivered to a thirsty engine when
more is requested.

 

Nice, that is probably the only thing I did not wanted to do myself on the car, changing the fuel pump. We'll see how things unfold...