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cbrahs

backfire sound

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ok, I have talked about this before (last winter on another site) and the truck is starting to do it again. In the mornings when the wait to start light comes on I start her up. wait for oil and everything to stabilize then kick on manual high idle to 1100rpm. when the grid heater cycles OFF the motor sounds like it backfires. It shakes the truck and usually only does it one time (NO CHECK ENGINE LIGHT AND NO CODES). I know what a backfire is, I am just using that as an example of what it sounds like. I have been shooting videos each morning to capture it on my phone so I can post it and show the dealer. It only happens when it has cold soaked usually overnight. Once it happens it usually does not do it again hence the PAI to get it on video. I will see if I can catch it on video and post it here to see what people think. Any help or ideas will be much helpful.

BTW- it was doing it long before I installed the bodylift (bodylift has a 3" spacer for the intake horn)

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it only does it with high idle set. VERY VERY slight when just at idle but nothing to write home about. I am trying to get a darn video, it has not been very cold at night for it to do it.

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sounds like an injector hanging for a second when cold. my rig has a similar issue at the moment. but its more like a loud knock than a backfire.

have you tried it without the Smarty????

one of my sub- contractors had a backfire problem, turned out to be a dirty air filter but his problem was different, it would backfire under load.

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no water/meth and it started doing it last year. I bought the truck october 20th last year and it did it last winter long before smarty. I am still trying to capture it on video, just has not been cold enough.

air cleaner is new (2 months old)

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no just my luck, it has not gotten cold enough. I have been trying to get it on video though so I can show you guys I aint crazy.

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it finally did it but it was not a loud one like usuall. About the 16-17 second mark is the backfire noise I have been hearing. I had the high idle set @ 1300 this time and still did it. I will keep trying to capture it on video so you can hear it really good. It is getting colder and will keep you guys posted.

http://s207.photobucket.com/albums/b...1109070740.flv

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Guest ShanesLB7
i can't wait til it is louder. when it is colder, it will do it.

Does it do it if the truck is plugged in or un-plugged??

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usually when i have it plugged in at night, i start it and head to work so I don't know. it has done it since new and LONG before I installed the smarty. I have talked to the dealer about it and they look at me like I am crazy. the bummer part is it is not regular. it could sit at the dealer for a week and MIGHT do it. I gets more consistant when the temps get colder so I am going to try and take a couple days off and leave it at the dealer and be there in the mornings when they start it up.

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It is supposed to snow tonight so tomorrow will be good. I showed the dealer the video clip the other day. They thought I was stoned last winter. He was like WTF!

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