1998 K1500 5.7 Vortec P0302 can’t figure it out
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CF Beginner
Joined: Oct 2018
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1998 K1500 5.7 Vortec P0302 can’t figure it out
Well first and foremost I’d like to say Hi! I’m new to the site and I’m hoping some of you automotive genius’s are able to help me out!! So to make a long story as short as possible the truck kicked the Cylinder 2 misfire. Replaced distributor, plugs, wires, coil, updated injector setup and fuel pump. Still had the issue. So i then removed and replaced the heads when i found the cylinder 2 exhaust valve wasn’t seated. Nothing was bent or hurt it just looked like it had a heavy carbon build up. So after the reinstall of the new heads and buttoning everything back up I’m feeling pretty good about it firing up and running well. Except i have sh*t luck. Started it up and it ran better but still missing and it’s still cylinder 2. At this point i guess I’m checking wiring, pcm and maybe the cam? I’m kind of at a loss and i greatly appreciate any feedback
CF Active Member
Joined: Jun 2014
Posts: 143
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Great Ideas! Compression test is a must, but be sure shrader valve is good on tester. I almost pulled head one time because shrader valve was sticking open and giving me false readings. But before compression test buy u some good insulated gloves and pull plug wires from distributor (one at a time) and notice if RPMs change. I have poor hearing so I have to monitor tack. This should tell you exactly which piston is not firing. If u have already performed this test, run compression and pray u don't have bad rings or a bad ring. At least u can isolate exactly which piston/cylinder is acting up. Having valve cover off will also show if lifter/rods are OK. I had an Pontiac rocker arm stud break one time. What a pain...