Axios

Alright, new info.

Did a compression test, cold obviously.

1. 105
2. 110
3. 110
4. 110
5. 0
6. 105

So that's the problem. Likely a hung intake valve on 5, I'm about to go do a wet test on 5 just to be thorough.

Axios

She's up and running smooth. The entire issue was the #5 intake valve stuck open. Tapped on it a couple of times with a hammer and it snapped shut. Soaked it (and all the other valves) in PB blaster for a week, and then replaced the bent pushrod. The pushrod had came out at some point and gotten wedged between the rocker arm and the head. I also found a bad throttle body gasket. Now that it's running on all 5, I'm going to reset the ignition timing, as the idle is a bit surgey. I also replaced the FPR and the ignition coil since I was in there. It runs so smooth that you can barely tell it's on while sitting in the truck. Also, the off idle stumble that it always had since my grandfather got it is GONE. Pretty sure that was the TB gasket issue. Matches the TSB about it anyway. Thanks for all the help guys!!

Steve83

The stuck valve is what bent the pushrod (when the rod dropped out of the rocker, and the cam pushed the lifter up again). The root cause is ethanol in the gas, instead of Lead (which lubricated the valve guides). Either buy lower-ethanol gas, or add MMO (or some other Lead-substitute) to your fuel & oil to keep the valves lubed.

Axios

Yeah, that's what I meant. I'm changing oil tomorrow, and making sure there's mmo 8n it. I already put some in the gas.