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Engine runs perfect just this issue.... Any ideas?

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Old 10-29-2015, 07:40 PM
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Default Engine runs perfect just this issue.... Any ideas?

I know i have a lot of friends on here that are more mech savvy than me, can anybody guess at what could make this popping noise? Only at idle, no miss runs smooth as silk, ive swaped everything... coils/plugs/wires/injectors/o2 sensors, the a/f ratio and compression is perfect as well.... ahhhhhhhhhhhh!!!!!!!!!!!! its coming from the right bank only and popping out of the exhaust no noise at engine... no exhaust leaks either




Old 10-29-2015, 07:43 PM
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99 ls1 from a t/a texas speed flat tops and cam as well as t/s tune.
Old 10-29-2015, 09:05 PM
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Ive had a dead cylinder sound similar. Assuming its a true dual exhaust with no X or H I would start simply with a heat gun on exhaust primaries on that side looking for anything out of the ordinary. Then pull one plug wire or coil pack at a time to see if you can narrow it down to a cylinder that way. Next i fo compession test and pull valve cover making sure everything is still together and moving properly.
Old 10-29-2015, 09:29 PM
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If I pull all injectors it stops, each one when hooked up makes noise, some more than others
Old 10-29-2015, 09:42 PM
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Im confused by the way you say "when each one is hooked up". Are you only hooking one at a time up? What i meant ist to only have one un hooked at a time while running. I actually wanted to say bent exhaust valve but hoping yhats not it for you
Old 10-30-2015, 05:55 AM
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Are you sure your exhaust isn't touching anywhere? Maybe something wrong with the muffler on that side? Could also b e an exhaust leak. Just some other simple things to check. I would also use an infrared temp gun and check all your exhaust primaries and see if any are lower temp then the rest and that will be the bad cylinder. I had a coil once that ran great at full throttle but didn't at part throttle and idle.
Old 10-30-2015, 06:23 PM
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well i found a vacuum leak on the intake and fixed that, it was the small port under the map sensor, all 8 pistons are wet with fuel after i run it and scope the cylinders, even to the point where i can see it run down the face of the piston, any ideas what sensor could make it run this rich?
Old 10-30-2015, 06:29 PM
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pics.
Attached Thumbnails Engine runs perfect just this issue.... Any ideas?-img_1274-1-.jpg   Engine runs perfect just this issue.... Any ideas?-img_1273-1-.jpg  
Old 10-31-2015, 12:46 AM
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Maybe it could be the tune if the there was vacuum leak at the MAP while tuning and that is now gone?
Old 10-31-2015, 09:28 AM
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I would think strait fuel would evaporate off a hot piston and wouldn't still be running down the piston by the time you got a bore scope in to look. Oil in the combustion chamber will take on a fuel smell. How are the valve seals, and have the heads been ported? I ask about the heads because usually when ported the intake rocker bolt hole is open to the intake runner.
Old 11-02-2015, 11:55 AM
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Maybe an injector is leaking. You have any tuning software?



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