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Help!!! Misfire

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Old Jul 25, 2009 | 08:05 PM
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Default Help!!! Misfire
I have a 98 camaro , I was driving it home car was running fine doing about 60. Got off on to a main road and slowed down to about 35 and the car started missing and pulled the ses light then it started flashing. I got it home and run the codes po 307 #7 misfire, po351 coil 1 malfunction, and a po353 #3 coil malfunction . Changed all plugs and put in new ngk tr55, and two new coils, now still got the #7 misfire. Any suggestions?
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Old Jul 25, 2009 | 08:16 PM
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If you have no other codes except #7 misfire....just make sure BOTH wire ends are "snapped" on good to the coil and the plug. Also, make sure the plug wire(s) are not touching the manifold pipes. Possible cracked spark plug in #7.


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Old Jul 25, 2009 | 08:38 PM
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Originally Posted by LS6427
If you have no other codes except #7 misfire....just make sure BOTH wire ends are "snapped" on good to the coil and the plug. Also, make sure the plug wire(s) are not touching the manifold pipes. Possible cracked spark plug in #7.


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new plugs and msd wires. both ends snapped on good. i have had them come lose before so i check them often
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Old Jul 25, 2009 | 08:42 PM
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Is it misfiring at all rpm's? Or just mid to high?

Swap the wires around see if that changes the misfire cylinder?
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Old Jul 25, 2009 | 08:45 PM
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Originally Posted by LS6427
Is it misfiring at all rpm's? Or just mid to high?

Swap the wires around see if that changes the misfire cylinder?
.
the car misfires at idle and if you rev it up. changed the wires around to still #7 misses like hell
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Old Jul 25, 2009 | 08:51 PM
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Next step then, take the plug out and make sure its not cracked. I'd also swap #7 fuel injector to see if the misfire moves with it.


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Old Jul 25, 2009 | 08:53 PM
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Originally Posted by LS6427
Next step then, take the plug out and make sure its not cracked. I'd also swap #7 fuel injector to see if the misfire moves with it.


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thanks i'll try that next
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Old Jul 26, 2009 | 01:20 PM
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just found out that i broke some valvesprings!(again???). i just can not figure out why this keeps happening? some friend who work on cars said someone has put a bigger cam in it and did not change the valve springs. could this be the cause????
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Old Jul 26, 2009 | 01:32 PM
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Originally Posted by tcondra
just found out that i broke some valvesprings!(again???). i just can not figure out why this keeps happening? some friend who work on cars said someone has put a bigger cam in it and did not change the valve springs. could this be the cause????
Yes. Also, getting on it hard (high rpm's) before the engine is warmed up, with high lift, can cause them to break.


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Old Jul 26, 2009 | 01:35 PM
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yes if someone did put a bigger cam in, then yes thats most likely the problem
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Old Jul 26, 2009 | 02:03 PM
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when i started pulling it apart we found that it has lunati push rods in it and noticed that it has new gaskets on the timing chain,heads and intake.just wish i could find out what springs i need to stop this.
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Old Jul 26, 2009 | 02:13 PM
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Originally Posted by tcondra
when i started pulling it apart we found that it has lunati push rods in it and noticed that it has new gaskets on the timing chain,heads and intake.just wish i could find out what springs i need to stop this.
I assume you have double springs?



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Old Jul 26, 2009 | 02:28 PM
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Originally Posted by LS6427
I assume you have double springs?



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they are stock i guess? i need to get new springs,retainers and locks to be safe. i just dont know what to get?? any help!!
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Old Jul 26, 2009 | 02:44 PM
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Originally Posted by tcondra
they are stock i guess? i need to get new springs,retainers and locks to be safe. i just dont know what to get?? any help!!
Holy ****...things could have ended badly. Dropping a valve.

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Old Jul 26, 2009 | 02:45 PM
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Have someone tell you what size cam you have, then get springs to match. Its easy.

Any good head shops around you?

I have Crane double springs in mine. .610 lift


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Old Jul 26, 2009 | 03:07 PM
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Originally Posted by LS6427
Have someone tell you what size cam you have, then get springs to match. Its easy.

Any good head shops around you?

I have Crane double springs in mine. .610 lift


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how can you tell what size cam with out taking the cam out?
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Old Jul 26, 2009 | 03:19 PM
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Originally Posted by tcondra
how can you tell what size cam with out taking the cam out?
I don't know, but I can only assume there's a way using the some super duper tool on the springs/valves.

Ask in a new thread in the "Internal Engine" section. I'd like to know too.


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