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Old 03-19-2009, 12:50 AM   #1
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Default Higher octane to fix missfire

i was wondering if i can add those higher octane addictive to boost up the octane level for the random misfire i get when starting the motor. This happens only when the engine is hot.. If i drive it for a while the misfire goes away as soon as the cylinders burn off the fuel thats in there.
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Old 03-19-2009, 01:04 AM   #2
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Higher octane gas is not the answer. You need to find out why you have the random misfires when the motor is hot and you are just starting it. You might have a coil pack going bad, a bad plug wire, injector hanging open, etc. I suspect that a higher octane gas will create bigger symptoms if you don't find and cure the real problem.
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Old 03-19-2009, 01:29 AM   #3
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I would suspect a bad spark plug. Change them all and see if it corrects the problem.
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Old 03-19-2009, 05:26 AM   #4
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yes, make sure you plugs and wires are in good shape.
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Old 03-19-2009, 08:12 AM   #5
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How old are the plugs and wires?

If you pull the wires off the coil'* one at a time, how many coil posts are rusted or corroded? (It'* quite common on our cars)

Are your number 4 or 6 plug wires touching the O2 sensor or wiring to it?

Do you happen to know what your fuel pressure is?
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Old 03-20-2009, 01:41 PM   #6
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Plugs Are new "Ac Delco"
Plug wires are new "Ac Delco"
Refurbished coils, same old module
refurbished MAF
No idea what teh fuel pressure is.


im thinking of shitty injectors, since i only have trouble starting her when hot :/

"Are your number 4 or 6 plug wires touching the O2 sensor or wiring to it? " not sure but what effect does it cause?

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Old 03-20-2009, 02:15 PM   #7
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Quote:
"Are your number 4 or 6 plug wires touching the O2 sensor or wiring to it? " not sure but what effect does it cause?
Causes interference with the signal from the sensor. This signal is used to set your AFR.

Still inspect your plugs, I've seen cracked plugs even when new.
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