Saturday Night Racer - back firing problume

W1CK3D R4C1NG

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Bakersfield

back firing problume
06/22/09 at 10:04am

i've been having problume's with my roadrunner, i cant get it to stop back firing... it has all new ignition parts (electronic) everything from the wiring to the distribitor... along with the back firing, it dont wanna stay running without turning the idle way up ur keeping your foot on the gas pedel... also yesterday i popped the radiator cap off and it was dry... and the other day when i was unloading it off the trailer, alot of water came poring out of the exaust...

i dont have the tools to do a compression test so i dont know if i have a bent valve or a cracked head...

anyone have any thoughts about what it could be? im leaning torward a cracked head, but theres no water in the oil... but i would love to have any other thoughts about it...

the motors a 400 big block...

Thanks...
Rich

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JKD, American Fab., Trinity Motorsports

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Tate #62 LMR God Offline WHEN IN DOUBT THROTTLE OUT Posts: 739	Re: back firing problume Reply #1 - 06/23/09 at 5:03pm idk but we had that problem with keepin e radiator full and when we rebuilt my motor a cuppl races ago i had a cracked head idk if that helps
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W1CK3D R4C1NG

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Re: back firing problume
Reply #2 - 06/23/09 at 5:16pm

that sucks... but thats kinda what im leaning toward... the only thing that makes me wonder, is it dont smoke at all and no water in the oil... so thats what made me wanna ask others thoughts on it... or maybe it was just deniel... i would hate to think a brand new motor with only about 50 miles on her, be bad already... but thanks for your info... now im gonna cry about the bad news...lol...

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JKD, American Fab., Trinity Motorsports

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jay99j LMR Member Offline lets put the stock back into hobby&street stocks Posts: 142	Re: back firing problume Reply #3 - 06/23/09 at 7:21pm if you know someone with a smog shop or a 4 gas machine you could have them check for hydro carbons in the cooling system or go to the parts store and buy a kit called a block tester it will also help check for hcs in the coolant i bet is a blown head gasket jmo
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W1CK3D R4C1NG LMR Senior Offline Posts: 492 Bakersfield	Re: back firing problume Reply #4 - 06/23/09 at 9:56pm head gasket might be a good posability... i'll call around and check out that block tester kit... ether that, or i'll just tear the heads off and have them checked out... thanks for the info... Thanks... Rich
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sundown LMR Rookie Offline I love YaBB 1G - SP1! Posts: 98	Re: back firing problume Reply #5 - 06/24/09 at 2:34am Fill the radiator with water----remove the sparkplugs---turn the engine over with the starter and look for a blow hole or is that looking for whales........
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formercrewguy LMR God Offline The shrub brothers are punks Posts: 4293 Arizona	Re: back firing problume Reply #6 - 06/24/09 at 8:23am Look for rust on the sparkplugs Check the torque on the heads/intake Do a leak-down Trade it for a Camaro.................lol
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W1CK3D R4C1NG

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Re: back firing problume
Reply #7 - 06/24/09 at 9:11am

lol... i might let you drive it a couple times for the camaro... Im a Mopar man, so that would be against all my heart, trading it for another make of car... dont get me wrong, Chevys arnt bad... and i would love to own a 68 camaro... but im not rich, so i can only have a couple toys at a time...lol...

i'll check out the plugs for rust... and the torque...

Thanks...
Rich

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JKD, American Fab., Trinity Motorsports

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miniguru27 LMR God Offline Dirt Late Models Rule! Posts: 652	Re: back firing problume Reply #8 - 06/25/09 at 10:03pm If that has solid lifters or not check the valve timing and or adjustment. that could cause a backfiring problem just an idea.
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miniguru27 LMR God Offline Dirt Late Models Rule! Posts: 652	Re: back firing problume Reply #9 - 06/25/09 at 10:05pm Also does the radiator pressurize really quick? Good indicator of a blown head gasket.
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W1CK3D R4C1NG

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Bakersfield

Re: back firing problume
Reply #10 - 06/26/09 at 7:57am

i never checked to see if the radiator is building up pressure, but i'll check it out and see what happens...

as for the valve's... i pulled the rocker arm shaft's off to check all the push rods, hoping maybe i bent one... but they were all good... after i put it all back together, it still ran the same...

its buggin me... all the symptoms point to timing problumes

wont idle, back firing, no power...

but were did the all the water go...lol... oh well... thanks everyone for your thoughts on this...

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JKD, American Fab., Trinity Motorsports

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miniguru27 LMR God Offline Dirt Late Models Rule! Posts: 652	Re: back firing problume Reply #11 - 06/26/09 at 9:27pm Definitly check the oil.and watch for steam out of the exaust or abnormal water out the tail pipes.
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miniguru27 LMR God Offline Dirt Late Models Rule! Posts: 652	Re: back firing problume Reply #12 - 06/26/09 at 9:31pm Also make sure the firing order is right.it still dont explain the vanishing water..
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W1CK3D R4C1NG

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Bakersfield

Re: back firing problume
Reply #13 - 06/27/09 at 8:12am

water in the tail pipe got me to check the radiator... when we unloaded it off the trailer, the back wheels went down the ramps first and a crap load of water came pouring out... and then the next mornin i got her started, she was blowing out all kinds of water... tomorrow im re stab the distibuter and redo all the plug wires and check all the plugs... maybe i'll find somthing... but like you said, it still wont help the water issue... but its worth doing just to see if she will run any better...

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JKD, American Fab., Trinity Motorsports

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miniguru27 LMR God Offline Dirt Late Models Rule! Posts: 652	Re: back firing problume Reply #14 - 06/28/09 at 2:43pm Unfortanatly it sounds like a cracked head.let me know what size motor and i might have some good heads.
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