Rough idel issue

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opfor2

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I'm having a slight rough idle issue. I have checked for a vacuum leak by using carb cleaner and nothing was found. I replaced all eight injectors about 6 months ago and my issue persists. I also cleaned the MAF sensor. I have attached my fuel trim both at idle and at 2000 rpm. I'm hoping someone can direct me on where to look next.
 

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j91z28d1

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I don't see anything off in the trims? when you spray the brake clean around did you watch the trims during it, or just listen? I've found the computers react to fast to hear, but you can see it in the short term trim.

plus and wires?

some higher end scanners have what they call balance test. sometimes it cna point you to a cyl that's off a bit and you can inspect from there if the standard tune up doesn't do it.
 

Fless

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Has the throttle body been cleaned lately?

In the scanner pic at idle, was the engine warmed up (in closed loop)? If so, I don't see anything odd there.

What about a slight misfire? Can you look at individual cylinder misfire counters on the scanner?
 
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opfor2

opfor2

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I don't see anything off in the trims? when you spray the brake clean around did you watch the trims during it, or just listen? I've found the computers react to fast to hear, but you can see it in the short term trim.

plus and wires?

some higher end scanners have what they call balance test. sometimes it cna point you to a cyl that's off a bit and you can inspect from there if the standard tune up doesn't do it.
No I just listened to the idle and I did not notice anything. The plugs and wires were replaced about 9 months ago using ACDelco products. I will try spraying the carb cleaner again while watching my reader.
 
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opfor2

opfor2

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Has the throttle body been cleaned lately?

In the scanner pic at idle, was the engine warmed up (in closed loop)? If so, I don't see anything odd there.

What about a slight misfire? Can you look at individual cylinder misfire counters on the scanner?
the TB was also removed and cleaned about 9 months ago. I also did a relearn upon reinstallation. And yes we were in a closed loop situation when I took the screen shot. I had no misfires but I will revisit this.
 

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