I have not so long ago bought a Jaguar X Type 2002 with 175k kilometers on it.
When I am uphill or when i try to kick the foot on the accelerator I have misfires that seem to almost totally turn the engine off. Also the engine seems like it is struggling.
The misfire happen from 1.5rpm to 2.5 (not higher).
Also I never have any check engine light since the number of misfires never reaches the threshold I imagine.
Diagnosing with torque pro (such a pity we don't have the PID-s of Jaguar) I did some tests of fuel trims and as well some tests.
Can't determine what bank the problem is happening. I notice though the long term fuel trims are high (+6 bank 1 and +9 bank2) when on idle.

Attached are some pictures of my torque and also the results of the test from torque.
What do you guys suggest to do further?

Pic 1: Idle
Pic 2: At 2500 rpm

 

That's often a coil. They're under extra stress in exactly the situations described.

Bear with me - it could be a battery problem instead. Sounds wacky but the big fast current needed for the coils comes from the battery. (The alternator recharges in a more steady manner.)

Sorry to give you two possibilities.

Those idle trims are a bit high. If you see those then rev do they quickly head nearer zero? If yes you have a small air leak. (I suspect as well as any coil issue.)

 

I will need to diagnose the batter first then. Most probably will need to do a load test of it. Do you have any source about loadtesting the battery?
The Idle trims are displayed in picture two when i rev to 2500rpm. They don't really go to 0. Also might be a air leak since when I drive in 5th gear only above 80kmph i hear a whistling noise coming from the front of the car. It might be the air leak that whistles. What would you suggest for diagnosing the airleak.

Also will try to load the car very heavily once so maybe I can make the misfires count pass the threshold to show a diagnostic code (hope this won't damage my catalytic though). Are the codes in general specifying which cylinder is misfiring?

Thanks for the help

 

If it is misfiring enough for you to feel it I am thinking that chances are it would be enough to trigger a code and the check engine light. Are you sure it is misfires and not maybe a fuel filter that might need replacing or possibly the fuel pump is starting to go?

 

I feel it a lot. It feels like the engine dies for a millisecond and then comes up again. If it would be a fuel pump wouldn't it show also in high rpm? I changed the fuel filter a month ago as well.

Also the fuel pressure in my readings is about 55psi. Is this normal?

I bought the car 2 months ago. If it is already the fuel pump I have been trolled...

 

After reading http://www.jagrepair.com/images/TSB/...g%20Issues.pdf I'm getting to think that it might really be the fuel pump problem. Any other way how to diagnose beside just monitoring the fuel pressure at the moments of the power loss?

 

Do you ever have a situation where it is hard to start the car or that it takes a longer time than usual to get it to start? That could be a sign of the fuel pump.

Do you know when the fuel filter was last changed? Could be something as simple as that. Easy and cheap to at least try before moving on to something more complex. You will at least take that out of the equation.

 

Not really. So far the car didn't experience any problem on start. It starts always in a matter of a second or two.
The fuel filter was changed last month (as soon as i got the car changed oil and all filter) so the fuel filter should be fine (is a Mann filter).

Worth mentioning that sometimes it is a little bit difficult to refuel the car, and also once when I was a little low on fuel (not on the fuel empty zone) the fuel gauge went all the way to empty and the trip computer had an error calculating fuel economy. After refueling the gauge went back to normal.

 

Today I had a check engine light turned on and I read the codes to be: P1582 Throttle Body. After reading in the forum I don't have any idea how this can be related to my problem though. Any idea?

 

Is that the only code you are getting? P1582 only records data and is usually associated with additional code(s). It is not related to the throttle body. It records data associated with momentary engine stalls and stumbles, which is what it sounds like you have. I have attached the list of P codes for the X-Type.

 

hey Alfadude. Yeah I was reading around the forum and has the suspicion it was not related with the throttle body the code P1582. I went to a service shop here in Stuttgart to read the codes and the codes they reported back to me in the paper were only P1582 and B1582. In the comment of the codes it says: P1582 Motordrosselklappe (means throttle body in german) and B1582 (something related with the lights). So im not sure if they reported me the correct codes then. In any case I bought an obd bluetooth scanner myself and read correctly the codes. Hopefully will be in tomorrow and will reread what is happening in my engine. Thanks a lot and will report back soon.

 

Also, if you notice in that list of codes it says that P1582 does not trigger the check engine light, so something else must have trigered it. There is another code that should show up when you check it with your code reader.

 

The OE diags can decode P1582.

 

I bought similar age/miles, had same exact issue, dreaded seeing a hill ahead.
I cleaned my MAF, used entire can, problem solved.
Made the wife tense all up when I punched it getting on the highway and the cat went like it should, after the cleaning.
Sure of same symptoms, could be the same cause.
PS, car sat a year in police impound undriven when I bought it

 

Will try cleaning MAF since it is such an easy thing to do. Thanks for the suggestion, didn't think about it.

 

clean the MAF, also do you know if the spark plugs have ever been replaced ?

 

finally had some time to deal with the car. Cleaned the MAF with almost half a bottle but no difference. Yesterday had to do along drive and after the drive finished I scanned the car with my OBD2. My car did have two codes that I see for the first time: P1111 and P1236 in a pending state. What does this mean? Is it really the fuel pump?

Thanks for the help, Regards

 

P1111 means the the car passed all the diagnostic checks, which is a good thing. That means that whatever issue you are having must not be present all the time and the system did not see a fault for a number of drive cycles.

As for the P1236, look at the list of codes I posted earlier. It refers to the fuel pump not being activated when requested by the ECM. Not sure if that is the fuel pump itslef or maybe something to do with the wiring.

 

Get the free downloads that tell you codes etc. Why ask when you can just read straight away AND get the known causes.

 

So I think I fixed my problem. Since when I bought the car I didn't add antifreeze. It was always below monimum point. I always thought that the line at minimum is the macimum level so never bothered to add antifreeze. Yesterday when I parked the car I noticed a strange water moving sounds( like a stream) and immediately inspected the antifreeze level. when I looked closely I finally noticed that the line at the antifreeze bottle is the min and the max is at the top of the bottle (really not readable if you don't pay attention). Immediately added antifreeze to the max. After I went for a drive I noticed that the temperature gauge was staying just one milimeter below medium (in the past was exactly staying at medium). When I try to accelerate hard as well in load condition the car didn't show any hesitation or stalling problems. I suppose this fixed the issue (eventhoueve need to try more.) Can somebody explain how antifreeze level can cause this. Was it because the car was running hotter than normal because of low antifreeze level? Did I cause any damage to the engine or catalytic converter?

Really feel a little bit ashamed for this mistake .would wou think that I would let my car starve for antifreeze.

I was actually last month thinking to do a fluid flush since I never did it since I got the car for six months now.