Number 1 cylinder missfire. What to do?

k_y86

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My number 1 cylinder is missfiring. Already chnged the coil pack. Car is already at 100000 miles. Spark plugs were changed with the bosch 4+ about 40000 miles ago. Fuel filter was replaced 30000 ago. Emptied a bottle of fuel injector cleaner into a full tank of fuel and the engine light continues to light up. Can somebody shed some light on this situation; do I need to replace the fuel injectors or is there a vaccum leak of some sort.
 

Revenant_SS

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Swap #1 and #4 plugs. Chances are you'll get the misfire on #4 now because Bosch plugs are pure garbage. Replace with a set of AC Delco or NGK.

Put it to you this way. If I have a customer coming in looking for a tuneup, I would send them to another shop before we'd put Bosch plugs in.
 

bryson87

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and if swaping the plugs dont work. swap the coil packs around also if it moves to the next cyl you put it on its the pack
 

k_y86

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no mods

Can you enlighten us on what has been done to the car as far as mods?

No mods have been done to this car just stock.

---------- Post added at 09:20 AM ---------- Previous post was at 09:18 AM ----------

Check the gap on the plugs

Can not gap the spark plug because it has the 4 of the things that you need to gap, not just one.

---------- Post added at 09:22 AM ---------- Previous post was at 09:20 AM ----------

Swap #1 and #4 plugs. Chances are you'll get the misfire on #4 now because Bosch plugs are pure garbage. Replace with a set of AC Delco or NGK.

Put it to you this way. If I have a customer coming in looking for a tuneup, I would send them to another shop before we'd put Bosch plugs in.

Already swaped spark plugs but with the #3 cylinder and it's still running the same.

---------- Post added at 09:25 AM ---------- Previous post was at 09:22 AM ----------

REplace fuel injector for that cylinder, make sure to change the o-ring and replace you MAP sensor.
Should fix it, just had same problem with #3 cylinder.

Dude I think your right because so far I've swaped the spark plugs and nothing so far. So where would the MAP sensor be located on a 2007 LS cobalt.
 

Spacey_stacey75

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well mine on an 06 was right under the intake, I think above the intake manifold

I went and bought the haynes repair manual so I could do this shit myself. I hate paying someone for something I can do.
 

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