misfire at idle

[dodgeguy82]

“I have a misfire in 3 cylinders I put new plugs,wire,cap,rotor,fuel pump. It only misfires at idle i have 141,000 miles on 99 dodge ram 1500 5.9 360”

Topic

[Michael Oliver]

Check the plug gap and make sure it is factory measurements. Check the coils by doing a power balance test. the video is on this website and is simple to do. Ill bet you will find the problem there. If one coil goes bad the engine code will sometimes read misfires on more than one cylinder because of unburned fuel in the bad cylinder. Hope this helps. keep us posted.

Michael O

[dodgeguy82]

I forgot i put new coil on and checked all vacuum lines plugs are gaped to factory spec.

[Bret]

could be a vacuum leak somewhere like on your intake manifold

[dodgeguy82]

How whould i check for vacuum leak at the intake manifold i dont hear any sould like a leak around the manifold

[Wayne]

[Bret]

should watch this video aswell it has a similar issue misfire at idle and its actually a vacuum leak

numerous other things that can cause it aswell, should be able to help you

[dodgeguy82]

i found the intake manifold leak and its fixed and it runs great with no misfire

Attachments:

• Blown_plenum_seal1.jpg

[EricTheCarGuy]

Very cool. I didn’t even have to weigh in on this one. Well done finding the issue. Thanks for the update and for using the ETCG forum.

[Author]

Replies