Misfire …again

[lftd94z71]

My stupid Vortec is misfiring again. Last time it was cylinder 8, after much digging and trial and error I discovered it was because the stud the rocker was sitting on had come out. So simple fix, put in a new one and redo all the settings. This time it's cylinder one, fortunately easier to get to after you pull everything off just haven't got to that point because it's so damn cold here. I changed out the spark plug and wire and still nothing. Took the distributed cap off and cleaned up the contacts put it all back together and still nothing. I was told to check out the ignition coil, but I thought that was only the case if the engine was missing on different cylinders each time. This is consistently cylinder one. Any ideas? This has me really

 

[IOWNJUNK]

Pull that plug back out and check compression. Broken rocker, bent pushrod, bent/stuck valve, all can cause that.

 

[badazzbulldog]

possible that the spider injector is leaking but I just noticed your screenname is it a 94 Z71? if so I would say its a tbi motor not a vortec

 

[lftd94z71]

Pull that plug back out and check compression. Broken rocker, bent pushrod, bent/stuck valve, all can cause that.

The rocker came off the stud and push rod on a different cylinder last time it misfired, I just haven't gotten to that yet on this side. I did check the compression and it has none. The spark plug and spider injection is working fine so I'm looking into the mechanical portions prolly gonna check that tomorrow.

possible that the spider injector is leaking but I just noticed your screenname is it a 94 Z71? if so I would say its a tbi motor not a vortec

Yeah I used to have a 94 loved that thing but some idiot hit my bed doin 50 and totaled it so now I'm working with a 98 it has the 350 Vortec in it.

 

[michael hurd]

No compression = no bueno. You have a mechanical condition for sure, not a 'prolly'.

 

[lftd94z71]

No compression = no bueno. You have a mechanical condition for sure, not a 'prolly'.

Yeah I figured that after I changed out all the electrical components related to it.

 

[IOWNJUNK]

Pull valve cover and look. Mine did same thing, ended up being a bent valve. Hopefully you just have a rocker issue.

 

[lftd94z71]

Pull valve cover and look. Mine did same thing, ended up being a bent valve. Hopefully you just have a rocker issue.

Was definitely a rocker issue, the damn factory defect where the studs come out happened again on the opposite side of the last time. Downside is the new studs are too big so I took off a little bit to make it fit but I didn't take off enough and cracked the head putting in the new stud and bent the $hit out of the stud. So now I have replace the head. Fun times.

 

[IOWNJUNK]

That sucks. Good thing is they're plentiful in the boneyard, put some valve stem seals in one and get busy. Its time consuming but as long as you label everything you take off its not too bad. Mark every single wire you disconnect with painters tape and a sharpie and put every bolt in a ziploc bag and mark where it goes.

 

[shortchevy]

Was definitely a rocker issue, the damn factory defect where the studs come out happened again on the opposite side of the last time. Downside is the new studs are too big so I took off a little bit to make it fit but I didn't take off enough and cracked the head putting in the new stud and bent the $hit out of the stud. So now I have replace the head. Fun times.

are you running a big lift cam? If you want some cheap insurance that it wont happen again even if you have a stock cam drill a hole through the cast tower and stud and install a roll pin. use a new drill bit and put locktight on the roll pin