Engine Misfiring like Crazy.

General engine questions/issues that aren't specific to the other categories
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Engine Misfiring like Crazy.

By Eli'sEG94
- Mon Aug 18, 2008 2:30 pm #66565 hey Guys as the title says I have a big problem with my engine everytime I start it up for the day or after it's been sitting for an hour or so, it starts to idle fluctuating between 1,000 and 2,000 RPM's and it sound like it's going to stall but it doesn't. the crazy part is that every now and then it sound like someone is shooting, well it missfires, so i'm looking for ideas where to check before I take it to a mechanic and have them charge me for something stupid.

My friend said there could be a leak somewhere and it's pulling air from there (possibly),

I was thinking the spark plug wires may be bad, but dunno how that can affect it.

it may be running rich and detonating, in which case it's really bad and I should not drive it.

Note: this only happens during warm up, and at startup. After it reaches operating temperatures all goes away.


Any Engine heads please help out. :(

PS: should have noted this is an LS\VTEC
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By teal_dx
- Mon Aug 18, 2008 4:43 pm #66575 Do you have any check engine light codes and have you done any work to the car before the problem began?

detonation is caused by runing lean, which may be caused by a bad o2 sensor.
Clean out the FITV/IACV on the throttle body/intake manifold. That could have to do with your idle problem. If the idle stays that high all the time then it could definitely be a vac leak.

If your plugs & plug wires are old, it couldn't hurt to change them too.
Maybe you are getting weak spark, which could not be burning all your fuel, which could be fouling your o2 sensor, causing your car to run like crap.
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By Eli'sEG94
- Mon Aug 18, 2008 5:08 pm #66579 Will get new wires at lunch brake ASAP.
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By Eli'sEG94
- Mon Aug 18, 2008 5:35 pm #66581 can I spray throttle body cleaner while the engine is on? o no?
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By Eli'sEG94
- Mon Aug 18, 2008 7:39 pm #66603 Changed the spark plug cables for some nice NGK ones, I found at NAPA, I'll confirm once I let the car cool down and see if it miss fires again. Anyone have a problem with the fitment of the wires, at the spark plug end, the little umbrella grommet does not fully fit. they work fine so I left them there, but just wanted to check if anyone else had this problem.
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By teal_dx
- Tue Aug 19, 2008 1:17 am #66635 sometimes you gotta pull on them a little bit to adjust them down. Just not too hard or they can break. Or most likely they sold you some kind of universal set for most civics. OEM sets will fit best.
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By Eli'sEG94
- Tue Aug 19, 2008 4:19 am #66656 car still misfires after changing the spark plug wires, thinking the O2 Censor might have been fouled some how, I am noticing how ever that after a brief period of sustaining high RPM's around 5,500 or even 6,000 I get a check engine light, I don't have a reader yet, but I'll get it check out soon when I do get it again.
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By Eli'sEG94
- Tue Aug 19, 2008 3:01 pm #66673 thanks man, but I have to check it after I get the check engine light, right? of course, I'll try it during my lunch brake.
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