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Discussion Starter #1
Hey all, my brother recently got a 96 C2500 (215k mi) with the 5.7 Vortec and he recently changed the spark plugs but not the wires (they're only a year old), but on startup the engine sounded a bit different and it's vibrating all around. A gas smell was heavily present and acceleration from 0-40 was much slower.

According to the internet this sounds like an engine misfire, however I don't see a check engine light? My brother reinstalled the spark plugs hoping one of them just went in wrong but nothing changed. The seller mentioned problems with the distributor but I'm just not sure how to help my brother out. I am a bit mechanically inclined so I wouldn't mind looking into DIY solutions, mostly since he can't go to a mechanic at the moment. I've considered replacing spark plugs maybe due to a faulty plug, but would a new distributor be worth it?
 

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Discussion Starter #5
Check the plug wires for reversals. This assumes good spark plugs and proper gaping.
The new plugs were ACDelco Platinum and I just checked over the wires according to the diagram online, they're in the correct places. I replaced the spark plugs with the old ones and it remained the same unfortunately. My brother mentioned that he pulled kind of hard to remove the wire from the plug, could he have ruined it with a hard pull? I
 

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Well since exchanging plugs did not fix the problem then you need to check spark to each cylinder. Could be bad wires too. You did say it ran good before the plug change so maybe the wires were compromised when removed.Do you have a spark tester to check?
 

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Well since exchanging plugs did not fix the problem then you need to check spark to each cylinder. Could be bad wires too. You did say it ran good before the plug change so maybe the wires were compromised when removed.Do you have a spark tester to check?
I don't have a spark plug tester but I just decided to get new spark plug wires and it managed to fix the problem, along with replacing the cap and rotor that came with the kit, no more misfires :cool:
 

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Look around for a loose vacuum line, could have been knocked off. Vac lines get old, it good to replace them from time to time.
 

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Hey all, my brother recently got a 96 C2500 (215k mi) with the 5.7 Vortec and he recently changed the spark plugs but not the wires (they're only a year old), but on startup the engine sounded a bit different and it's vibrating all around. A gas smell was heavily present and acceleration from 0-40 was much slower.

According to the internet this sounds like an engine misfire, however I don't see a check engine light? My brother reinstalled the spark plugs hoping one of them just went in wrong but nothing changed. The seller mentioned problems with the distributor but I'm just not sure how to help my brother out. I am a bit mechanically inclined so I wouldn't mind looking into DIY solutions, mostly since he can't go to a mechanic at the moment. I've considered replacing spark plugs maybe due to a faulty plug, but would a new distributor be worth it?
Triple check the wires. I had the same problem because 2 wires were crossed. Also replace the wires if they are all connected correctly.
 
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