my car starts good for 5 seconds then runs rough then good

2007 JAGUAR X-TYPE
30,000 MILES
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M3GTR8
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hi ,
previously i had an oil leakage and i fixed it .
after 2 weeks , car makes a popping sound and gone into limp mode ,
replaced plugs and coils and cleaned injectors and throttle body and replaced throttle position sensor , checked battery and alternator .
it is out of limp mode , but , on first start in the morning , it runs rough for like 10 minutes , until temperature gauge reaches half (normal) and it runs fine for the rest of the day .
no check engine light .
Apr 12, 2012 at 9:20 PM
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HMAC300
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check for a vacuum leak, sounds like you have one and computer is richening mix up to compensate for it.
Apr 12, 2012 at 10:34 PM
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M3GTR8
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thanks , and what is the best way to check for this ?
smoke machine ? carb cleaner ? or else ?
Apr 13, 2012 at 9:27 AM
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HMAC300
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you'll have to check all your hoses first like seeing if they are disconnected, holes ,etc. take car b cleaner and spray around intake, connections etc. but nnyou'll have to do it cold unless you find the problem first.
Apr 13, 2012 at 2:16 PM
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M3GTR8
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no vaccum leaks found ,
scan tools show p0300 (random misfire codes)
my check engine light doesn't work (even if i disconnect a sensor )
can you list me other possibilities to check for ?
Apr 20, 2012 at 11:31 AM
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HMAC300
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if it's arandom misfire make sure to check your fuel pressure as it will cause this.it lshould be 46-55 lbs or 320-380 kpa if measuring metric. i am sassuming this is a gas vehicle not diesel.
Apr 20, 2012 at 2:09 PM
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M3GTR8
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true , it is a gas vehicle , i also noticed that when driving , if i push on the pedal fast , there is a slight hesitation and it continues fine .
Apr 20, 2012 at 2:55 PM