2002 4.6 rough idle
03-22-2011, 06:13 PM
#1
FORD~ Found On Race Day
Thread Starter
Join Date: Feb 2011
Location: Johnsburg ny
Posts: 401
Likes: 0
Received 0 Likes
on
0 Posts
2002 4.6 rough idle
My 02 4.6 has a rough idle it feels like a diesel what could it be it has a new tune up n the codes read cyl 1 so I replaced the coil and still rough idle but now no codes any ideas?
03-22-2011, 10:22 PM
#2
Senior Member
03-24-2011, 07:59 PM
#5
Is it a rough idle or a misfire. They're very different. Does it clear up when you hit the gas? Check the connectors to the injector and coil, the tabs on the coil connector like to break and come loose, I just wire tie them tight. Can you do a compression test, if so compare it with a good cylinder. If you cleared the code it won't come back until it sees the problem in more than one drive cycle and misfires have to be seen a certain percentage of total rotations. If it's just rough idle it could be a vacuum leak, IAC, MAF or another sensor left unplugged.
03-24-2011, 08:03 PM
#6
FORD~ Found On Race Day
Thread Starter
Join Date: Feb 2011
Location: Johnsburg ny
Posts: 401
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Austin97
Is it a rough idle or a misfire. They're very different. Does it clear up when you hit the gas? Check the connectors to the injector and coil, the tabs on the coil connector like to break and come loose, I just wire tie them tight. Can you do a compression test, if so compare it with a good cylinder. If you cleared the code it won't come back until it sees the problem in more than one drive cycle and misfires have to be seen a certain percentage of total rotations. If it's just rough idle it could be a vacuum leak, IAC, MAF or another sensor left unplugged.
03-24-2011, 08:10 PM
#7
Unless you have a compression tester you'll need a shop to do it. It's a tool with a gauge that screws in where the spark plug goes and shows the compression of the cylinder. Like I said just look over the connectors and follow all the vacuum lines to make sure there's none that came off or broke. How long has it been since air/fuel filters?
Trending Topics
03-24-2011, 08:36 PM
#9
FORD~ Found On Race Day
Thread Starter
Join Date: Feb 2011
Location: Johnsburg ny
Posts: 401
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by otto457
Compression should be in the 105-165 range. Vacuum lines, check them all and the base of the throttle body.
03-24-2011, 08:39 PM
#10
FORD~ Found On Race Day
Thread Starter
Join Date: Feb 2011
Location: Johnsburg ny
Posts: 401
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Austin97
Unless you have a compression tester you'll need a shop to do it. It's a tool with a gauge that screws in where the spark plug goes and shows the compression of the cylinder. Like I said just look over the connectors and follow all the vacuum lines to make sure there's none that came off or broke. How long has it been since air/fuel filters?
