4.3L sierra no start

GMC SIERRA
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TENNYKIMBLE
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2000 gmc sierra 4.3L 83k the truck will tun over but not start. it also backfires (up thru the throttle body intake) a small amount while trying to start. after a rough start, the truck ran fine the day before.but today it would not (fire) start. i tried replacing the crank position sensor, ignition coil and ingition control module( i think that what its called - its a small eletrical device on the side of the coil). no difference. i have 60 psi of fuel pressure. i replaced the fuel filter. and its got decent spark. the plug is wet with fuel. also either (and gas down the intake) only makes if backfire worse. i have checked all fuses-none blown. it's acting like it's out of time, but it ran the day before? it has a mechanical type distributor that seems to be working fine- i took the cap off and it is spinning and the contacts are not pitted. any info would help!! im stuck! :?: i work on diesels-not gassers. :? :wink:
Feb 26, 2007 at 8:20 PM
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CHEVY22
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hmm, any codes show up ??? there is one thing , the cam sensor in the distributor, the cam sensor adjusts fuel for each cylinder, its more like ia timing device , if it goes bad it has a one in six chance of fueling the correct cylinder , fuel pressure sounds good

how long since the plugs have been replaced

let me know jim
Feb 26, 2007 at 9:17 PM
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TENNYKIMBLE
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a p1351 code showed up? it came up as " IC CIRCUT HIGH VOLTAGE" i cleared it and it didnt come back. the plugs looked okay- i'll pick a set up just to be sure, but i dont think that is the problem. is the cam sensor in the distributor or in the engine block? thanks for the advise!! any info is much appreciated!!!! :D
Feb 27, 2007 at 3:39 PM
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CHEVY22
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the cam sensor is under the rotor , the ic code directly effects your symptoms and it wont come back until the vehicle is running , it is located next to the coil its actually called ignition control module and it works off the crank sensor , if someone close has a truck with a 4.3 96 and up would work , swap one out just to test it

hope this helps

jim

oh the gm plugs are a must , i used to have customers come in with random misfires right after replaing their plugs and we put delcos back in and wham its good so i swear by them
Feb 27, 2007 at 4:04 PM
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JBOYD103
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My 2000 Sierra 4.3 has the same problem.

Have you fixed yours? If so, what was it?

Mine is down and I am running out of money!
Apr 16, 2007 at 8:06 PM
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KIRBSTER269
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Iwas running ok then it would die and start right back up till finally it started no more. I have spark fuel system is all good getting the backfire through the throttle body. I am strongly thinking its the timing chain going to take it off and check the alignment but I replace alot of stuff and a know go even disconnected the exhaust thinking stopped up cat convertor no go there but it will take me a few days so I'll try and keep you informed
Jun 26, 2007 at 12:07 AM
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