350 Tbi running bad

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bucket

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Didn't read everything but just listened to the video. Sounds like a cam going flat. Sounds like the problem is with one cylinder for sure. Compression test and/or pulling plug wires one at a time to isolate cylinders would be where I'd go next.
 

Camatruder

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Hi, you mentioned that the back firing got slowly worse which makes me think it's a timing issue f.e. the distributor that turned slowly. When setting the timing, you did disconnect the tan wire and set the timing 0° right (see instructions on post 21)? Also, did you check if there are fault codes present ? Not all intermittent faults trigger the Check Engine Light.
 

Jonesie

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Back fire thru the intake and exhaust, gradual loss of power: Locate and remove the O2 sensor, leave the hole open and fire it up. If after a couple of seconds it starts reving, and gains power ,the cat converter is bad and needs replaced along with the O2 sensor.
 

ratchetmaster

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I read through the posts. Have you replaced the distributor cap and rotor? If not, do it now. If yes, then continue forward. :D
 

ratchetmaster

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If you haven't yet replaced the fuel filter, then do it now before proceeding. if you have done it recently, then carry on. :D
 

ratchetmaster

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Have you checked all of your vacuum lines? IF not, then check them all.
 

ratchetmaster

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There has been some great advice on the thread.

Someone here suggested on starting with the simple things . . . I agree.
All the other info provided by the posters is great info.

Keep us posted on how it goes.
 

ratchetmaster

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One more observation. . . as mentioned the timing chain problem or a worn out cam are good possibilities with that many miles. Checking vacuum, egr, compression, fuel pressure, removing one plug wire at a time and seeing how it affects idle and drive-ability and seeing how it affects the engine are all good ideas.
 

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any update from the OP?
 

87silveradok20

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I agree

You can see the exhaust light up at the end of the clip... although the flash is near the cat versus tailpipe.
You mean the muffler? No cats here


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Cuba

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You mean the muffler? No cats here


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Yeah, I realize no cats, but as a reference point. Where the cat would be... way up in the beginning. Not where the muffler is. ;P
 

87silveradok20

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Here's an update to the this thread. I deleted the egr and attempted to reset the timing again and realized I hadn't unplugged the tan wire. I unplugged the wire and the truck won't run without it plugged in. Any idea what the problem could be?


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bucket

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Here's an update to the this thread. I deleted the egr and attempted to reset the timing again and realized I hadn't unplugged the tan wire. I unplugged the wire and the truck won't run without it plugged in. Any idea what the problem could be?


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With an otherwise healthy engine, it would mean the timing is too far retarded.
 

87silveradok20

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With an otherwise healthy engine, it would mean the timing is too far retarded.
Sorry If this is a dumb question but does that mean I should turn the distributor clock wise or counter clock wise. (Should he clockwise right?)


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