Hey guys,

Lately i have been experiencing a misfire at idle only.I have the torque app and I get between 1 to 20 misfires at each start-up .I can feel most of them . Now i have a faulty injector in cylinder #5 which is causing almost all the misfires and I'm going to change or clean it soon. My question is that the other cylinders are also misfiring randomly but i cant feel them , i only notice the misfires in the app . For example i get 1 count for cyl #1, 2 counts for cyl #8, the next time neither cyl #1 or #8 misfire and so on. I've changed the spark plugs recently , checked the ignition coils, changed the fuel filter, ran a couple bottles of FI cleaner which helped for few days . The car has almost 105k miles on it. Waiting for your replies.

Thanx in advance .

Alam

 

Depends on what's causing the misfire. Does your app tell you if it's spark related or fuel related?

Fuel related: Whatever impurities caused the misfire in cylinder 5 are probably still stuck in the injector and somewhat stuck in the other injectors. FI cleaner only works if the material can be broken down small enough to pass through the injector. If you've already ran a couple of them through, I'd say your next bet is to replace the injectors.

Spark Related: How old are the plugs? If you don't know, it wouldn't hurt to take one out and see the condition. Perhaps they've never been changed?

If you take a plug out, follow the TSB to prevent issues.
TSB PDF:
http://www.phila.gov/fleet/Warranty%...-06%20FORD.pdf

 

Are you running aftermarket or the stock COPs?

 

Well the app only shows the number of misfires.As for the spark plugs ive already changed them.


Stock ones.

 

Check your plugs for being loose. Wouldn't hurt to pull them out and make sure they aren't fouled. Three forum members so far over the summer have had misfires from loose plugs when other possible causes have been ruled out.

 

What FI cleaner are you using? Seafoam has fixed misfires for a lot of Mustangs. Also, when checking for fouling check the gap. Maybe one got dropped and the gap has changed. Do you have a code reader? (I don't know what the Torque app does)

 

Already did that , 2 of them were loose and the exhaust gases escaped through them which left a brown mark on the coils. All plugs looked clean. Still the misfire exists.

Im using STP and one time ive used valvoline , We dont have seafoam here in UAE. Im using the motorcraft plugs which have closed tips . No codes and car is running great .

 

STP and others like it aren't as effective as seafoam. Any chance you can order online and have it shipped in?

 

If there's no codes and it runs good, then stop chasing a none issue.