Followed advice and the instructions in the how to and cleared the p0171 and p0174 codes. Found a collapsed vaccum elbow below the lower intake manifold. Since everything was off I replaced the coils and spark plugs and all gaskets. Buttoned everything up and now the car won't run. Starts idles rough and then dies. No codes currently and no running car... least I could drive it before. Need help quick I thank you all in advance.

 

Something left unconnected or cross-connected, or a biggish air leak due to a gasket gap/etc.

 

+1 on something missed

Check if manifold sitting flush and all the bolts are tightened - when I did mine the first time missed out on a bolt or two and upper manifold wasn't quite buttoned up though your sounds like you missed connecting something big.

 

All is connected took pictures so I could make sure everything was right but as for those individual little manifold gaskets there is a decent chance that I may have overtightened a bolt or two. Couldn't find torque specs. Set them in place with black RTV to keep them in place but that might not seal if they are crushed. May have to do a redo on the upper and lower manifolds. By chance does anyone know the part numbers for the one piece gaskets?

 

Did you check the how to section? ;-0

https://www.jaguarforums.com/forum/s...ype-faq-69962/

 

What I am having a problem with is that you have no codes. Before you start pulling things apart again take a look at all your electrical connectors and vacuum lines on the top end chances are one of them is leaking. I am going to provide a link to my procedure that might offer a different point of view. I hope it helps.

Link JagRepair.com - Jaguar Repair Information Resource

 

Possibly so confused that it hasn't figured out what codes to flag
Or it will do, in a while.

 

That's the writeup I used to find the initial problem. Just disconnected and reconnected vacuum lines and found the connector of one damaged so I replaced it. No change but I did notice white smoke from the exhaust. There is a black box with 2 vacuum lines going into it on the back of the intake manifold that looks a little beat up but I don't know what its for. Has a ford part number f77e-9j460-ab but I will have to look that up tomorrow since my resources are currently limited.

 

3.0 vacuum lines are in a pic in stickies.
Failing that, JEPS / JTIS and a bit of hunting should find info.

 

I have to agree with everyone else above. You have had to missed something when putting all back together.

Where did you apply the Black RTV?

 

I applied RTV on the manifold both upper and lower to help hold the gaskets in place. If i did miss something its not one that I can reach on top so I will have to unbutton everything and start over.

 

There could be an issue there.

If you haven't replaced the vacuum lines, they are known to be very brittle and crack at places that are not easily seen.



Been there before. I am now able to remove the upper plenum within 15 minutes.

 

May I hi-jack for a moment? If an engine only runs rough when cold, would that mean there's not a vacuum leak but a temp controlled device in the vacuum system? If so, what components are heat related in the vacuum routes?

 

95% or 99% an air leak. $10 OBD tool and watch LTFTs with live data. See my sig though re car details.

 

Back from a bit at sea and the OEM style gaskets were here so I took everything apart again and replaced the felpro things that I probably misinstalled. Now she runs so looks as tho the air leak theory was probably correct. Original codes are clear and no CEL anymore. Thanks for all the help.

 

Thanks for the follow up!

 

Hey thanks for the follow up.