So this is my second post about my issue because my first post didnt get me anywhere. I have a 2002 jaguar xtype 3.0 and when it has been left overnight and started in the morning it has and erratic idle sort of a chugging idle, when i rev the ending to about 2k it runs smooth, if i let go it will get eratic again. when driving it drives fine until you come to a stop where the revs again drop low and erratic and there is no hydraulic brake pressure so its quite difficult to stop. once the engine warms up it is fine i can turn it off and crank it back up and it will run perfect. it seems the Jag just doesnt like the cold. i got a suggestion to change the intake manifold seals. does anyone have any suggestions? thanks

 

The fact that this issue effects the breaks might be a clue. Have you
carefully checked the hose from the intake manifold to the power
break booster unit? Perhaps the hose has a crack that opens up
when it is cold. Rubber gets harder when cold.

If the breaks work properly, asside from being very hard to push, then
you are likely not getting enough vacuum to the booster. Such a leak
will make the engine run poorly, especially at idle.

Pete.

 

Yeah I would suggest checking your vacuum lines for leaks as you could have some cracked lines and thereby dropping pressure in the system

 

As with more than a couple of recent threads here recently, the problem you describe could be related to some just plain worn out spark plugs.

Your Jag is a pretty high compression engine, and bad plugs and a cold engine could be the recipe for it having morning fits. The key is you mention "once the engine warms up it is fine".

When you're changing out the plugs is a perfect time to replace the intake manifold gaskets, too!

 

I have the same problems with my car. When Its chugging like that, its running at very low rpms. I noticed when going down my hill when cold i had no brakes. The 2nd time I went down I gave it just enough throttle in neutral to run smooth. Brakes worked fine. After it warms up, it than runs smooth again (At the idle its supposed to be at) and your brakes all work fine again. I'm almost positive that I'm in need of intake gaskets. I havnt gotten around to doing them yet, all though will hopefully get to them this week. I have had this same exact problem on a ford escape that the intake gaskets fixed. Hmmm..Maybe I'll go tackle the tune up today.. I'll be sure to let you know if I do!

 

Gorhad, do you have any check engine lights lit on the dash? From your description the issue sounds serious enough that there would be a warning light on.

 

Yeah my issue is the exact same a joeboat84.

Jagger i replace the brake booster hose so it isnt that.

bracester i have checked all the lines they check out fine.

Alfadude there are no lights or anything coming up.

Bruce ill take that into consideration i ordered both upper and lower intak manifold gaskets i am going to get a set of plugs and put them all in ill let you guys know if it clears the problem should have them in by the end of the weekend

Thanks for the suggestions and help guys

 

I have no cel either. In the am before it warms up when idleing, she'll putt, pop, and seem like she wants to stall. A little warm up and she runs like new. I have all the gaskets (Felpro from my autoparts store for a 3.0 - 15 and 20 bucks for the 2 sets) and plugs. I just need to pick up 3 coil packs for it to replace the 3 under the intake.. I don't want to pull this apart if i don't have to. Hopefully I'll have time before the weekend. This snow may put a damper on things if we get it tonight.

If you get yours done first, let me know how it works out, but I would bet it'll smooth out for ya.

 

What 3 coil packs under the intake????

 

It worked ! It's solved the problem not only did it solve the erratic idle and chugging in the morning it also idles a tad but higher. The old seals were so bad that they cracked taking them out ! Thanks joeboat84 you were a great help thanks everyone.