LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Backfiring @ Idle after Header Install

Old Nov 21, 2009 | 12:49 PM
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Question Backfiring @ Idle after Header Install

Well just finished up putting the Ebay long tube headers on and the Loudmouth exhaust is all bolted up. Now at idle it backfires but has no problems under load. Anyone have similar problems after doing any kind of header install no matter what brand it is? Also I have no exhaust leaks and all my ignition wires are all seperated and new.
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Old Nov 21, 2009 | 12:50 PM
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mess up a plug or 2 while the removal and install?
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Old Nov 21, 2009 | 12:57 PM
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I'll pull them out and check if thy are fouled. I've only put 45 miles on the car yesterday after I got her started. Maybe the computer is confused with the new set-up. I had the car sitting in the garage for 2 months with the battery disconnected.
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Old Nov 21, 2009 | 04:22 PM
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unlikely. check for any burnt or cracked plug wires and plugs.
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Old Nov 21, 2009 | 04:28 PM
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Did you unplug the plugwires for any reason during the install? Might have put them on wrong..?
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Old Nov 21, 2009 | 05:42 PM
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Wires all look good and just pulled the plugs. The plugs are showing signs of wear on the tips, gonna go get some new ones in a few minutes. One of the plugs when I was unscrewing them felt like it was out of round from the ceramic end, weird but I don't think it's broke or anything.
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Old Nov 21, 2009 | 05:45 PM
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Hey Badazz 97 TA, did you delete all your emissions equipment on your header install. I still have the EGR hooked-up and capped off one of the vacuum lines that went to the AIR pump. Did you have any problems with yours?
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Old Nov 21, 2009 | 06:36 PM
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plug wires mixed up
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Old Nov 21, 2009 | 06:46 PM
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Originally Posted by Badazz 97 TA
unlikely. check for any burnt or cracked plug wires and plugs.
+2. i cracked 2 of mine when i installed LTs, and it took me about a week to figure it out. when i finally went to check the plugs, as i was taking them out i could feel the split through the gloves and was like WTF? the split went all the way down the side
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Old Nov 21, 2009 | 07:20 PM
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Just got some TR55's, let's see what happens..... I've also checked the checked the wires and order of them and they match the right cylinders.
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Old Nov 21, 2009 | 10:02 PM
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Let us know what happens.
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Old Nov 22, 2009 | 06:56 PM
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Put new plugs in and changed out my Accel wires for my old MSD's and found a small crack on the #5 wire. Fired her up and she runs super smooth now, those little things make a big difference! Thanks for the help guys
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Old Nov 22, 2009 | 07:15 PM
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Originally Posted by SS#502
Hey Badazz 97 TA, did you delete all your emissions equipment on your header install. I still have the EGR hooked-up and capped off one of the vacuum lines that went to the AIR pump. Did you have any problems with yours?
i originally had everything hooked up. The back tube for the EGR was a PITA to bolt up. no problems with anything when it was hooked up. i eventually just capped off everything and got rid of all that crap
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