Wondering if any of you X types perhaps had the same problem. My 2003 X-Type has been running just fine but was leaking a little oil from the valve covers. With new valve gaskets, decided to install new plugs and coil kit from Amazon. It's a Autodevil UF435 Ignition Coil Pack & SP479 Iridium Spark Plugs. So put it back together and it would not idle and halfway run at high RPM. So pulled it all apart again figured I did something stupid but could not find anything wrong other than the parts I installed? Going to reinstall the old parts and see if that's the problem and hopefully it is since anything else is scary to think of

 

Hopefully you did not damage any of the vacuum tubes.
Especially there is one, which is routed quite stupidly from (when you stand in front of the car) the right side of the engine to the rear of the engine, and as it is quite fiddly to put the air-intake back on and you have to juggle it a bit, it happens easily that this vacuum hose lands in the wrong position, while you put the air-intake on, and it gets squeezed badly by the air-intake on top, i.e. the tube would be blocked and the air-intake has a leakage, as it does not sit properly.

Make sure you do not forget to re-connect ALL of the connectors again. The most likely one to forget is the throttle motor adjuster, which sits hidden under the big black rubber hose coming from the air-box just before the air-intake. Also look for damages cables - again especially to the connector of the just mentioned throttle motor adjuster.

 

Yeah it does sound like a major vacuum leak somewhere. I have the intake manifold off again so will zero in on the vacuum lines. Thanks

 

Problem turned out to be bad upper manifold gaskets I purchased from Amazon. When I installed them I thought they were sloppy compared to the old ones I took out. So luckily, I hadn't thrown away the old gaskets and reinstall them that immediately fix the problem. The new lower ones seem to be okay for now anyways. The Amazon upper gaskets measured .09" width and my OEM uppers measure .16" and are rounded at the end instead of squared. In any event it's been a real battle.

Here is the amazon part I ordered to stay away from

Brand Middrivr
Material Rubber
UPC 733371218414
Manufacturer Middrivr

 

The other Old Addage is, "You get what you paid for".

Glad you got it fixed.

Jack