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lazydog76, Chevy Technician
Category: Chevy
Satisfied Customers: 203
Experience:  10 years exp professional, ase master, gm tech
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2004 chevy silverado 1500: has a miss to it..rpms..jumping

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I own a 2004 chevy silverado 1500 5.3l it has 94000 miles on it, so I decided to change the plugs and wires in it and now it has a miss to it more noticable a lower rpms and when it does miss it sounds like spark jumping. I doubled checked everything and even bought higher dollar wires. Was running good before I changed them. Not understanding what might of happened?
hi what kind of wires and spark plugs did you purchase
Customer: replied 8 years ago.
ac delco rapid fires platinum plugs    bwd select super mag wires
did you gap the spark plugs
Customer: replied 8 years ago.

ok these spark plugs are non adjustable which means they are pregaped and do not need to be gaped due to the reason of damaging the spark plugs. this is a copy from ac delco for your truck. hope this will help. and always replace using ac delco parts.


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Part Number: 41-985
Product Notes:
[Iridium-Spark Plug]; DO NOT DEVIATE FROM PRESET GAP .040 ; .040 GAP
Per Vehicle: 8; Years: 1999-2005

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Customer: replied 8 years ago.
they were gapped at .060 and thats what they told me they were supposed to be at but what i dont understand is the ticking noise i here every time it starts to miss would u here that noise if the gap was to big and only seems to be coming from one side

check the plugs for a crack on the ceramic portion of the plug. you can use a spray bottle with water in it and spray on the wires to see if you can locate the cylinder. also is the check engine light on?


but yes the ac delco rapid fires platinum plugs are gaped at 60 and should not be regaped.

Customer: replied 8 years ago.
they are trying to tell me it is one of my coils and if the plug was cracked wouldnt it be ticking constintly
no it would not have to tick constantly, usually when wet or moisture, hot or under load. a coil usually does not have external spark. is the check engine light on, as it should be if you have a missfire like your describing.
Customer: replied 8 years ago.
no check engine light isnt on
i would go back and double check the spark plugs and wires that you installed. i think your problem is in the spark plugs. but you need to double check the plugs.... if you would give me the vin number please so i can make sure what engine you have.
Customer: replied 8 years ago.
1gcek19t24e309478 (lm7)   was does the water do?
water is a conductor of electricity so it will ground out on the engine and if it a bad wire or cracked plug it will cause it to spark, you do this in a spray bottle and spray a mist on the ignition wires and even the coils... what did you gap the plugs on and what is the part number of the ones that you removed. i will cross them.
Customer: replied 8 years ago.
thank you very much i will check the plugs
if you keep having the problem i would replace the spark plugs using the same as was in it before you changed them or with the number i listed above. just a note if a plug is not sparking like it should the coil is still firing and the spark is going to go to the weakest spot or grounding location. and if the gap is not as listed above or on the label under the hood it will cause problems and missfire. so i am sure the plugs are causing your problem