05-04-2012, 10:01 AM | #1 |
Drives: chevy Join Date: Jan 2011
Location: cleveland ohio
Posts: 847
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backfire after cam install
We did a cam swap all is plugged in and upon firing up I get a backfire over and over drivers side header gets hot quick only let it run maybe 3 to 5 seconds at a time the passenger header stays cool my question are the injectors not pulsing??Could this be a bad ground car doesnt have any check engine lights or anything I'm baffled any ideas i could look at
Mods are Nite fury cam Fast lsx 102 w v ring and stock ported tb Lts 3in exhaust Backlashed valves Injen intake Comp double roller w ls2dampener Stock fuel rails and injectors w the fast spacers |
05-04-2012, 10:27 AM | #2 |
Drives: Red 2010 Camaro 2SS L99 Join Date: Apr 2010
Location: Naperville, IL
Posts: 208
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Timing could be off
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2010 Camaro 2SS/RS L99 6AT - 451 RWHP, 414 RWTQ
TSP VVT-3 Cam DOD/AFM Delete, Ported Stock Heads, Circle-D 2B Multi Disk Converter, Custom 3" Exhaust w/Burns Mufflers Exhaust Clip: http://youtu.be/c_quv8eoVNQ |
05-04-2012, 10:36 AM | #3 |
Drives: chevy Join Date: Jan 2011
Location: cleveland ohio
Posts: 847
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Motor was out of the car before I put it back in i spun the motor and everything went in order as the book said so I'm stumped
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05-04-2012, 11:10 AM | #4 |
Did you check the pushrods lengths? I doubt it is but it's always worth looking into.
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05-04-2012, 11:54 AM | #5 |
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Drives: 2012 Camaro RS, RX supercharged Join Date: Dec 2009
Location: Bradenton, FL
Posts: 6,063
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Possible to long of pushrods as well (didn't include that in the PM). You need to measure for proper preload and length very last after the engine is assembled & heads torqued down. Any guessing before that stage is just that, guessing. We constantly see cars come in from other shops where they just put in suggested length pushrods and usually they are to short and the valvetrain is noisy, but also see them to long (which yours would be if that is what is causing your symptoms).
You want app 1/2-1 full turn of the pedistal bolt from zero lash. |
05-04-2012, 12:07 PM | #6 |
Drives: chevy Join Date: Jan 2011
Location: cleveland ohio
Posts: 847
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I used the rods that came w my cam kit from lethal racing
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05-04-2012, 01:28 PM | #7 |
Drives: 1985 Mazda RX-7 6.0L H/C/I Join Date: May 2012
Location: Sparks, NV
Posts: 1
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subscribed for resolution.
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05-04-2012, 01:45 PM | #8 |
Drives: 2017 1SS 1LE - Hyper Blue, P85DL Join Date: Jul 2011
Location: East Bay
Posts: 2,189
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What are you idling at? Too low of an idle or bogging a cam can produce a backfire.
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05-04-2012, 01:57 PM | #9 |
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Drives: 2012 Camaro RS, RX supercharged Join Date: Dec 2009
Location: Bradenton, FL
Posts: 6,063
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So you didn't measure for proper length & preload? Pull a valve cover & I can walk you through it all. I assume they sent the length that usually works as they know what they are doing...good shop, but it is always reccomended to measure to ensure. We keep a bunch of different lengths in stock as we dont ever assume a certain length will be correct, but if the heads and head gaskets are stock...heads not milled, then you can make a good guess.
Don't get to frustrated....It should not be hard to correct. |
05-04-2012, 02:06 PM | #10 |
Drives: 2010 CAMARO. 10.04@133mph, 1.4 60' Join Date: Jul 2009
Location: Lafayette, Louisiana
Posts: 4,585
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Tracey is correct. We use the 7.425 push rods with the Night Fury cam, but always check it after the heads are torqued. Every engine is different
check for coil bind also? Was this an Ls3 converstion? Are your front O2 sensors plugged in? Coil packs plugged in and grounded? Pinched wire under coil pack possibly? |
05-04-2012, 02:41 PM | #11 |
Drives: chevy Join Date: Jan 2011
Location: cleveland ohio
Posts: 847
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Idle at like 750 I think. I'll take a peek
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05-04-2012, 02:43 PM | #12 |
Drives: chevy Join Date: Jan 2011
Location: cleveland ohio
Posts: 847
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Heads were milled about 10 thousands
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05-04-2012, 03:11 PM | #13 |
Drives: 2010 CAMARO. 10.04@133mph, 1.4 60' Join Date: Jul 2009
Location: Lafayette, Louisiana
Posts: 4,585
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If they were milled you def need to check the pushrod length
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05-04-2012, 03:16 PM | #14 |
Drives: chevy Join Date: Jan 2011
Location: cleveland ohio
Posts: 847
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No this was not a conversion lol its a ls3 from the factory
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