LT1-LT4 Modifications 1993-97 Gen II Small Block V8

BAD Missfire....

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Old Dec 23, 2010 | 12:00 PM
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Default BAD Missfire....

Got everything back togeather after the head gaskets swap... Start it up, it has a bad missfire, the engine is rocking side to side real hard, and it sounds like complete **** and like it is choking when i give it gas.

The fuel injector might not be pushed all the way down (orange strip is still showing), could that cause a mis?

Maybe spark plugs are cracked, They were dropped a few times?

Any ideas?
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Old Dec 23, 2010 | 12:04 PM
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sounds like crossed wires... like on the wrong plug
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Old Dec 23, 2010 | 12:34 PM
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That's what I was thinking. We tried checking, drivers side looks good, but we can't see the opti on passenger side
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Old Dec 23, 2010 | 12:56 PM
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More opinions.!!!!!.... I need it running ASAP!!!!
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Old Dec 23, 2010 | 01:10 PM
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Originally Posted by SpeedFreak123
That's what I was thinking. We tried checking, drivers side looks good, but we can't see the opti on passenger side
I don't get it. You are looking for more things to check and you haven't even finished checking what you've been told to?
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Old Dec 23, 2010 | 01:55 PM
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Originally Posted by LSWHO
I don't get it. You are looking for more things to check and you haven't even finished checking what you've been told to?
My car is at my cousins house on blocks. It has to be out of there tonight my uncle said. So i am trying to get a list of things to check so i can go over and if one doesn't work, I'll go to the next.
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Old Dec 23, 2010 | 02:42 PM
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Forgot to mention that when it does start the oil pressure is above 80 on the gauge?

Btw, it doesn't want to start anymore, but has enough battery juice.... ignition right?
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Old Dec 23, 2010 | 04:21 PM
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The questions you're asking indicate you have no idea what you're doing. Quit skipping around and let people give you answers.
1) If you dropped the plugs, replace them.
2) You must check ALL of the wires and make sure they're connected to the proper cylinders.
3) If your fuel injector isn't down all the way, then push it in the rest of the way (duh).
4) Check to make sure everything sensor-wise is hooked up (TPS, IAC, MAF, MAP, etc).
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Old Dec 23, 2010 | 04:23 PM
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opti opti opti, sounds like it took a **** on you
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Old Dec 23, 2010 | 07:32 PM
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All wires are on correctly.

I got it running but it has a bad miss, still.

We ran the code and it said P0305 which is "cylinder 5 misfire" .

I pulled the plug, its fine.

Maybe the wires bad. ?

Yeah, your right I don't know what I'm doing, that's why I'm on here asking for answers.
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Old Dec 24, 2010 | 01:44 AM
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How do you know the plug you pulled is fine? Just because it looks fine doesn't mean it is. Replace it just to be sure.
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Old Dec 24, 2010 | 01:49 AM
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here is what you do replace opti, wires, check wiring, plugs and then see if you still have a problem
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Old Dec 24, 2010 | 02:53 PM
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I had the same problem for 3 months, replaced fuel pump, fuel filter, spark plugs, spark plug wires, injectors, MAF, tuned it, didn't touch the opti, ended up trading the car in and getting a 07 cobalt so I can save some money and star from scratch and do **** the right way
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Old Dec 24, 2010 | 06:32 PM
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We checked the wire with a Voltage Meter, it said 0 Resistance which is very uncommon, prob. a bad wire. We did have to tug on it pretty hard to get it from between the tubes on the headers.

The wire im speaking about is cylinder 5. Im going to try and replace that wire and see if it helps.
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Old Dec 24, 2010 | 06:34 PM
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BTW, we got it running again, and ran the code while it was running and the SES light was flashing, and it showed P0305 "Cylinder 5 misfire".
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Old Dec 24, 2010 | 10:58 PM
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melted wire grounded to the headers then right?
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Old Dec 24, 2010 | 11:06 PM
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its your wire, thats the only thing that would cause it
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Old Dec 26, 2010 | 03:25 PM
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I got a set of MSD wires for sale, PN 32129 they are fitted to go over the valve covers probably about two months old maybe 200 miles on them, 100 bucks takes them, let me know if interested
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Old Dec 26, 2010 | 04:23 PM
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did you tighten your rockers correctly?
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Old Dec 29, 2010 | 11:30 PM
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We tried the wire .. it was off a Chevy 350 with reg. distributor, we rigged uit up to make connection tho... didnt fix it.

My mechanic thinks the piston ring could be messed up???? ouch! Does anyone think its the ring?

Rockers were tightened down till the pushrod could spin in your fingers, then a half turn back.
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