I am new to here and i need help. There a misfire in cylinder in number four causing the truck to run really rough at times and when i step on it, it sometimes takes me quite a few seconds to get to cruising speed. Sputtering and shaking of course along with terrible fuel mileage. I have changed the fuel filter and plugs, cleaned out the throttle body and added a bottle of Gumout fuel injector cleaner to about a 3/4 tank of gas. Any suggestions on what i should do next? I bought a new coil pack today but wont be able to put it on tomorrow, hopefully that will do the trick. Vehicle is a 1996 Chevy Silverado 4x4 with the Vortec 5.7
Help, cylinder misfire, rough idle, significant power loss
- Thread starter JrsK1500
- Start date
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Have you checked the cap, rotor, plug wires or fuel pressure? It could also be a stuck poppet for that cylinder.
When I change the coil pack ill look at the cap and rotor. And the wire for cylinder number 4 I switched with the wire from the plug next to it. Scanned it and it still said the misfire was in cylinder 4. So the wires are still good. And as for a stuck poppet how would I go about that to see if its stuck? And the truck doesn't always idle rough. Only at times, but when accelerating (underload) it seems to be the worsr
Cap would be my bet. I had a similar problem recently, and my cap was just under two years old, and ended up being the issue. If you replace it, get a quality unit like an ACDelco, and replace the rotor while you're there. I
WFO4X4
Banned
if it was the coil pac you'd be missing on two cylinders not just one IIRC. we... that is unless there's one pac per cylinder.... i'm not able to recall if the vortec was set up like that?
Nope one coil on the pass side of the intake just like the tbi trucks.....
If you only have a misfire on one plug its probably not the coil. The flashing ses however is probably P0300 - multiple misfires.
How have you tracked it down to the #4 cylinder?
If you only have a misfire on one plug its probably not the coil. The flashing ses however is probably P0300 - multiple misfires.
How have you tracked it down to the #4 cylinder?
WFO4X4
Banned
they aren't coil over plugs? or is that the LS motors? either way, if it's only one coil it'll miss on random cyliners not just one. so you need to focus on the electricial route for that one cylinder. like was stated before either wire, which youve eleminated, or cap and rotor. which is most likely. and the cheapest.
Nope that started with the ls series
