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cylinder 1 missfire 99 malbu


wade623
01-20-2008, 12:45 AM
the check engine light came on so i had them check it and they said that it was missfireing but i dont know why and it only did this after i changed the spark plugs

so i was wondering if anybody had any ideas of what it could be

16th hippy
01-21-2008, 01:42 AM
what engine? did you replace wires? were any wires removed from coil packs? if yes to either one, make sure wires are FULLY seated onto plugs. if so, then remove one at a time from coil packs to check for corroded coil towers. if corroded, replace coil pack. spark plug could be faulty. post back engine size and what you find.

wade623
01-22-2008, 12:08 AM
3.1 v6 new wires, new plugs

16th hippy
01-22-2008, 05:26 AM
did you check items listed above?

wade623
01-22-2008, 12:06 PM
yeah i did

jaybo80
01-23-2008, 11:44 AM
What brand of plugs did you put in? I have a 99 with the 2.4 4 cyl. Had Same type of problem, was also making care shift strange. I had replaced orig. plugs at around 110,000 with Bosch plugs. didn't fix problem, after another 15-20,000 misfire was so bad car would hardly run. After talking to a local shop manager he told me if they have one come in with Bosch plugs they replace them before they even scan the computer because they are such a bad plug.I replaced the Bosch plugs with AC Delco plugs, it runs better than it has for years and the shift problem is gone.

good luck

jonnik
01-23-2008, 08:27 PM
On the 2.4 Ecotec engines, it is extremely important to stick with OEM ignition parts. I've never installed non-OEM plugs without some sort of performance problems that disappeared with the installation of the correct type A-C Delco plugs.

rhandwor
01-26-2008, 08:27 AM
Start with the plug wire use an ohm meter it should be about mid range. A lot of people pull the wire apart when they disconnect the wire. Pull the plug is it cracked or improperly gapped. This is the most common problems I found when plugs were changed and it started missing.

fritcr
02-01-2008, 10:51 AM
Bosch plugs are crap. Had the same problem on my bu. I put ac in and no problem. Also cracked a plug (and didn't know it) on my Trans Am one time and liked to never got that one figured out. yeah, I have also pulled the wire apart inside the boot where it plugs onto the plug on something. Who knows what...I have had so many cars I get them all confused.
Rob

wafrederick
02-03-2008, 01:19 PM
I agree,Bosch plugs are junk and the best thing to do with them is throw them away replacing them with AC Delco.Anything made by Bosch is junk,All my father has bad luck is made by Bosch.It could be the #1 fuel injector too and the 3100 has problems with fuel injectors.When a missfire is detected,the injector with the missfire problem is shut off and kicks the service engine light on.Some scan tools have a missfire gragh in them and GM's factory scan tool,Tech 2 is one of them.

wade623
02-04-2008, 03:25 AM
they are the autolite platnum and after i put them in i found out one was cracked so i put one of the old ones back in but it still felt the same i didnt know it was a missfire till later when the light came on

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