troubble shooting

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Feb 19, 2009 | 04:21 PM

courios gorge

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From: crandon Wi

troubble shooting

i have just put a offenhauser intake on my truck it is a 78 ford with a 400 and i put a 4 barrel carb on and it ran good more power but then i got a leak in my intake because i used the valley pan so i got the recomended gaskets i put them in and the leak has stopped but when i put the distibuter back in i back fired it through the carb and now my truck feels sluggish and underpowerd and it smells rich and i woundering if i blew out the power valve.

Feb 19, 2009 | 05:29 PM

75F350

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You have to first see and verify that you have the timing correct. If you backfired the engine through the carb, then the timing at some point was off. If that is the case, then you have to properly set that. Once you are confident that the timing is correct then you can address the carb issue.
Yes, if you run a Holley and you backfired through the carb, you can bet that the power valve has been destroyed. If it blew completely out, and it is torn, then fuel will be delivered and it will run rich during partial throttle and closed throttle operation.

Feb 19, 2009 | 05:35 PM

fmc400

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From: Austin, TX

Your timing is off. You should have checked the base ignition timing with a timing light after you installed the distributor. Did you?

Feb 19, 2009 | 05:36 PM

akparker1

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I'm with 75f350, power valve is my bet!

Feb 19, 2009 | 06:10 PM

andrewk

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The power valve may have blown with the back fire, but you've got to make sure the timing is right on the distributor before you go messing with power valves.

Feb 20, 2009 | 07:34 AM

courios gorge

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From: crandon Wi

i do have the timming right after it back fired i realized i messed up so i re set the timing to the specs on the valve cover, so i think that my power valve is sol