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bad injector maybe?

7K views 54 replies 10 participants last post by  ZXthrizzle05 
#1 ·
I replaced with a new coil pack and had it temporarily mounted and shot a video of it shortly after I fired it up. it still seems rough and under boost it still misses. the spark plug on cylinder 2 had white on it
 
#4 ·
For this misfire you changed the coil pack, but did you change the plugs?? You said the plug was white. Can you take a pic of it? If your car is running lean maybe you have a leak somewhere which would explain the rough idle and fluctuating rpms.
 
#5 ·
th emotor doesn't have tha tmany miles it actually only has 6k miles, it has a built motor in it. the gage cluster is just the stock one. I am guessing its the wire like italo said. I put some used motorcraft plugs in and ill try later, they have lke 1.5k miles on them
 
#14 ·
I have been semi retired for almost 5 years but still doing 100% tuning , building engines and turbo kits but only for the Focus

I just looked through my emails and I have no datalogs left to look over , whats your email and I will do a search to see if it went to junk mail but didnt see any

Tom
 
#29 ·
That does sound right, it really doesn't resemble a totally dead cylinder at idle and in the video, the car seems to run fine with some revs and once you get into any boost which would basically negate any vacuum leak idle problems due to the proportionally way smaller air intake volume at idle, it also disproves any doubts about ignition because it seems to be running well with more combustion pressure at speed and when boosting. When you're boosting does it feel down on power any? Does the AFR stabilize more if you're cruising steady speed with some boost present? If the AFR is stablizing under more engine load, in theory that directly points to a vacuum/boost leak.

Neither you or MotherFocus have directly stated that this is a recently built engine, if that's the case it might just be a matter of some intake piping that popped a little loose somewhere.

I don't have any firsthand FI experience, surely Tom and others here could validate or disprove that it's a vacuum/boost leak.
 
#30 ·
a vacuum leak will be almost irrelevant at wot. it will become just a small boost leak. although it would be unmetered it would have to be a large leak and a vacuum leak that large will affect the idle more than any thing.
 
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