My 2002 XKR smells like it is running rich (not a raw gas smell) when I get out after driving it, but no check engine light. Anyone have a similar occurrence? Would I get a code if it needed new O2 sensors? Anything else that would cause a rich condition, or is this just "normal" for freakin' awesome Jags?

 

Check fuel trims...

 

Get a code reader that will display fuel trims, almost every one on the market. Check the Long term and short term fuel trims LTFT, STFT for both banks and come back with the numbers.

You could destroy the catalytic converters if the engine is running too rich, and it could revert to reduced performance or even limp mode to protect the cats.

 

So here's the fuel trim data I pulled tonight. Looks like it is running rich and trying to compensate. No OBD codes in memory. Any usual suspects?

-Cabel

 

I am unable to open the file. Perhaps some one will help.

 

Try this .PDF file. Thanks!

 

Also i just pulled the air inlet off the throttle body and found several possible issues. One, the throttle body is pretty gunked up, so I'm going to pick up some throttle body and MAF sensor cleaner on way home from work tomorrow. Also, there are cracks and several small holes in the intake tube bellows. In addition, is that an XK8 MAF sensor? I was reading this DIY article and there are definitely two versions (http://matt.zenfolio.com/diy_document_clean_mafs.pdf) but again, no OBD codes have been tripped. Guess I need to go parts shopping.

-Cabel

 

cracks in the bellows like that are a common cause of vacuum leak, definitely replace or tape that intake.
my xkr MAF looks like yours, you should check the part number to be sure.

 

Ok, so my LTFT1 is averaging 12.90, LTFT2 about 11.93, indicating the the car is seeing a lean condition it is trying to compensate for. O2 Sensor voltages are averaging about .40v over this range which leads me to believe they are probably OK. So doing more research I need to definitely take care of the vacuum leak in the intake bellows then check for other air leaks, clean the dirty MAF and TB. If still off, check for a weak fuel pump (pressure test) and/or PCV plumbing leaks. Hopefully this will take care of it. Anything else on the XKR that is a common cause of a lean condition?

-Cabel

 

You are clearly on the right track fixing these air leaks. Those are allowing un-metered air and will force the fuel trims up. Pay attention when you put a new intake tube. Make sure it sits low, otherwise it rubs on the hood liner, and eventually leaks.

I would not worry too much about the fuel pressure as your fuel pump is clearly able to provide the fuel required for the additional air. Replacing an old fuel filter is always good, though.

Separately, fuel trims are stored in the ECM as the height of a "3D" map, if you will, with the other 2 dimensions being Engine Load and rpm. AFAIK, you could graph this, based on a data capture file off of TorquePro/ELM327. If you search this forum, you can find a couple of great tutorials.

As a general statement, use the specific kind of cleaner for the air flow meter. Folks have reported problems after using other things. Also, it looks like these air flow meter/intake air temp sensors are used on LOTS of cars, and can be found (refurbished) CHEAP on eBay.

It was not all that cold recently in the area, but are your intake air temperature numbers a bit on the high side? Are they close to the ambient air temperature in the A/C display? FWIW, mine are off 10-15 deg right now.

Best of luck, keep us posted.

 

I think the bellows leak repair will solve the problem. The gasket that seals the intake pipe to the throttle body can degrade and cause a leak, but your trims are not bad so I wouldn't search further until the bellows is repaired.

 

Ordered a new air tube and some other small parts needed from Terry's Jaguar Parts. Not bad pricing for Jaguar stuff. Thanks again for the comments.

-Cabel

 

I cleaned up everything and did a temporary patch on the air tube bellows until the new one comes in, rechecked the fuel trims and the STFT readings went to mostly zero, bouncing around occasionally between +/- 3%-5%. Much better than 18%-25%! Thanks again.

-Cabel

 

Are the LTFTs near zero at idle, too?

 

Not sure, I'll need to look at the log file when I get a chance but seemed to be consistently in the low range.