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cylinder 7 misfire help

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Old 04-03-2014, 06:15 PM
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Try it now
Old 04-03-2014, 06:16 PM
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[QUOTE=crainholio;18127294]Newb: See post #14.

OP: bring #7 to top dead center and see if you can push the pushrod end of the intake & exh rocker down at all. There is usually an audible ticking noise accompanying lifter failures...any noise on yours?
no I csnt press down but watch the video and you'll see my concern possibly a stuck or tight lifter. An yes the compressions great on all cylinders
Old 04-03-2014, 07:58 PM
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Originally Posted by johnny89345
Try it now
Video is still private.
Old 04-03-2014, 11:31 PM
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Sorry this was my first YouTube post and it'd the only way to send videos. Its not private now I figured it out
Old 04-05-2014, 01:05 AM
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I'm still guessing bent valve, if the stem is bent it can hang up in the valve guide. It seriously would take less time to do a compression check than to take off your valve covers and coils just do it already! Free rental at autozone what are you waiting for?
Old 04-05-2014, 01:45 AM
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[QUOTE=Mike_hawk;18130858] Compressions good bro reread everything I posted its at 190psi on all cylinder.dumI don't get how it would just randomly bend a valve. I

Last edited by johnny89345; 04-05-2014 at 01:53 AM.
Old 04-05-2014, 01:50 PM
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Sorry man, didn't see you had done the compression test already. Did you still have all the spark plugs installed in the video? The engine might be turning after you let off the starter. My next step would be to get an inline spark plug tester or timing light and see if it's firing on that cylinder like it should be. If that checks out it only leaves the injector wiring/PCM.
Old 04-05-2014, 04:55 PM
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That wasn't meant to be rude by the way. Yea sparks perfect. I had the same idea about the computer so I just dropped at my tuners house a little while ago. I'll let you guys know what he comes up with shortly I reallyhope thats all it is bec this motors pretty much brand new and yes all wires and injectors are unhooked in the video

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Old 04-06-2014, 12:55 PM
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Hope you get it figured out. I was asking about the spark plugs being installed in the video, if they were the engine could be making compression and turn the engine backwards/forwards after you let off the starter, so the one valve slowly going back could be unrelated to your problem.
Old 04-06-2014, 08:38 PM
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Man to me it seems like that lifter may be bad. I had the same problem once and it ended up being a bad lifter. check that out
Old 04-06-2014, 09:14 PM
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Have you done a running compression test? A static compression will show good but if there's a bent or cracked valve or bad valve seat a running/dynamic compression test can/will show it.
Old 04-07-2014, 12:16 PM
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So I picked it up from my tuner last night. He didnt fix it but looked it all over. He said start by fixing/adding grounds and replace the alternator which is putting out around 12 volts which he says might not be high enough. He believes its a wiring problem as he said the spark looked stronger on the passenger Side over the drivers side.
Old 04-08-2014, 10:32 AM
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For the record it does seem like my lifters making a light tapping noise
Old 04-08-2014, 08:03 PM
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I bet that's what it is. I haven't torn one of those apart yet. But shouldn't be to bad
Old 04-09-2014, 03:26 PM
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Originally Posted by camaroboy408
I bet that's what it is. I haven't torn one of those apart yet. But shouldn't be to bad
Tore what apart the top end or harness?
Old 04-09-2014, 03:50 PM
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Something new now lol i changed the oil last night now today its lower then it usually is. Normally idles at about 40-45 and goes up to about 75 now its bouncing a little at idle near 30 and goes up to maybe 50-55psi
Old 04-09-2014, 08:19 PM
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Originally Posted by johnny89345
Tore what apart the top end or harness?
The top end. fixing to tear into mine here pretty soon. Mines making lifter noise
Old 04-09-2014, 11:06 PM
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What gets me is the way it runs is so inconsistent. Today it ran pretty good but last night it was break in up snd running like complete crap down low. The 160amp alternator will be here on friday so lets all pray the tuners first impression on the situation is right. I really don't have the time for this right now and if im going in I need to upgrade lol

Last edited by johnny89345; 04-10-2014 at 06:54 PM.
Old 04-13-2014, 12:48 AM
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Well the alternator seems to have fixed the problem. But the oil pressure now if on the fritz. Since I did right beforr i did an oil Chang last week I noticed it was lower then normal and it flickers at idle. The motor only has about 10k miles on it btw so what are your thoughts on this?
Old 04-13-2014, 11:42 AM
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Mine did the same thing and it was the oil pressure sending unit.


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