hi, it's been a while since the last time I posted about the rough running so I thought I'd start a new thread.

2004 X-type, 2.5, manual trans

my OBD2 reader says I usually have both cylinder banks running lean, every few days, I'll get random misfires. Mostly, it's bank 1 running lean.

short term fuel trim is all over the place, I don't have a long term on the app I bought

here is what all has been replaced:
1) 4 o2 sensors
2) plugs, coils, and manifold seals
3) IMT seals
4) brake vacuum hose
5) EGR valve and hose
6) MAF sensor
7) accordian hose between air cleaner and intake manifold
8) injectors were cleaned out with BG's injector cleaner
9) fuel filter
10) Throttle position sensor, since the old one was bad

in other words, anything that can hold a vacuum has been replaced.

Everything that was replaced, one item at a time, showed an improvement.

it's really bad when it's cold outside, it's more apt to throw a check engine light. It's not so bad when it's warm outside.

car runs slightly rough at 70mph, it's smooth as silk above 80, tires are all good


so.... what else am I missing, or do I also have a bad sensor somewhere?

 

Have you checked the crankcase breather system?

In a case such as this, it may save time and avoid additional parts replacement by having a smoke test performed to determine the source of the vacuum leak as it may prove to be very small.

Since it appears to be temperature related, it may be a plastic hose or fitting that has a slight crack.

 

I replaced the PCV valve. Is there anything else there for me to look at in that system?

FWIW, the PCV valve for the Lincoln LS is exactly the same, except it doesn't have the 90° nipple on it like the Jaguar part has, and it's in stock at most auto parts stores. They have to order the Jag part.

 

Gas cap?

 

Have you unplugged and cleaned the various connectors to the throttle body and MAF? I had a problem with the connector on the underside of the throttle body. It was basically toatst from engine heat and had came loose. I was able to reconnect the spade connectors individually.

 

After all that money I'm thinking it would be worth getting a tool which also does LTFTs.

 

I'm in a similar situation so I paid the money for Autoenginuity. I also had to get an old laptop since it works with Windows XP (drivers) but Windows 7 just kills the drivers so no use.
I'm still learning more about the tool but it does have a mine of info available.
Should be about 200-250 dollars.

 

Did you check the lower intake manifold seals?

 

i have sprayed starting fluid at all the usual suspects where vacuum leaks can occur, like the intake manifold seals, the hoses, lower manifold gasket, etc, but there were no rpm changes.

 

You might want to get a scan tool that can graphically record/display the sensors. That will give you more insight into what is going on.