Hi all
Just bought 2006 xj VDP with 33k miles on it , drove it for few miles and check engine went on then the car stopped , will let rest for few and it will start again, test for leak could not find any, misfire codes for 1,3,7 also 0171 and 0174 codes, changed 8 spark plugs and switch coils , engine check went off but codes still there, sometimes the car will run ok then suddenly it is week and won't move then turned off! Abs light is on. Carfax says the car was driven 100 miles in the last year since serviced ( fuel pump and speed sensor replace)
What do you think is the cause?
Thank you

 

Have you checked the inlet manifold gaskets for leaks?

Lots of ideas here:

https://www.cargurus.com/Cars/Discus...28442_ds538713

https://www.google.com/search?q=p017...hrome&ie=UTF-8

 

You might search this forum for those OBDII codes - there is a great deal of information about the various causes as these are quite common codes (I had them in my '05 VDP) but there can be various causes. But Meirion1 is correct - it is probably a vacuum leak somewhere. The problem is there are a lot of places it could come from. I found some minor ones, but my problem actually turned out to be the MAF sensor. Cleaning it didn't work - I had to replace it (along with the PCV and fuel filter). Hopefully you won't have to go that far. There are really simple things like making sure the air intake is pushed all the way onto the throttle body and the clamp is tight. Mine slipped off twice..... You might also want to read around in the forum about Lambda readings from the upstream O2 sensors and the fuel trim data that you can get from an ODBII scanner. Those tell you if the engine is running rich or lean (yours are lean codes) and if the left and right engine banks are running the same or different (that gives clues as to what the cause could be) (Bank 1 is passenger side; Bank 2 is drivers side) You can spend a lot, or not so much, on one of those (look at the list of ones that work for our cars and the ones that don't). Mine was about $100 and gives the basic info including "Live Data" while the engine is running. Stick with it - you'll find it eventually. Could be a combination of things like mine. But when you get this sorted out and do the other catch-up maintenance that I'm working through on mine ('05 with 69,000) you should have a nice car with only 33,000! BTW, how did the old plugs look? All of mine were tan/light brown and crusty - they were the original plugs so that condition was what you would expect since mine was also running lean. Given that yours sat for so long you could have clogged injectors - that will also cause a lean condition.

Since I'm a newbie also, if I have anything wrong I'd appreciate the experienced members giving correct info!

 

I was lucky to find a good mechanic, he replaced file valve and pressure sensor , the car runs like a champ now

 

Mohab,

what is the file valve? I suspect MAP Sensor is the pressure sensor you are referring to. please confirm. I have the same codes on my 2005 XRJ.

 

My P0171 returned and after checking things over again the vacuum leak is coming from the EGR valve or associated items (EGR pipe, gasket, etc)

As a result I'm going to take the SC off do that hose and rectify everything while I put everything back together...

 

abonano if this is on your XJR I would suspect the PB vacuum connection on the SC elbow at the back of the engine.
But I think you know about that already?
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I changed it out a few weeks ago. Checked it with starter fluid, it's now solid!

When I spray near the EGR valve STFT's go full neg.

 

OK Thanks for the correction.
I have seen a hole in the accordion looking steel tube from corrosion once or twice.
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