wassup peoples ,
to cut it short ,
after many research for this problem ,
rough idle on cold start with engine shaking and popping sound ,
it dissapears when car is hot and remains so for 8 or 9 hours ,
i thought of plugs and coils and throttle position sensor and MAF and EGR and brake booster and PCV ,
after replacing all .
discovered , by advice of professional mechanic that it is either , ect sensor , vaccum leak , fuel filter .
for me , it was a vaccum leak from intake manifold gasket , it expands when hot and seals .
fuel filter produced similar problem ,
as well as ect sensor .
here is proof : Northstar rough idle at startup: vacuum leak - YouTube (similar to mine) .
hope it helps .

 

salam im yousaf

ive been a jaguar owner for eight years now and i have understood jags quite alot.

im happy your problem was sorted out, ive logged onto here after a longtime.

this is a really good website for advice and to learn new things

i wanted to know see the leak you had from intake manifold gasket was it from the upper gasket? or the lower one?

and did you fix it yourself or get it done mechanic?

thanks

 

hey there ,
it was an air leak from the upper intake manifold , i had one bolt loose , turned out to be the socket is broken , had to get a gasket sealant and put generous amount around the gaskets and let it dry for a while then close everything tight .
lower intake manifold usually present with either coolant or oil leak along with air leak .

you can fix it urself at home , but i recommend a good mechanic cuz you might forget to return things back together or tighten the manifold in the correct way .