1995 350 tbi rebuild - valve adjustment problems. Help!

[relderado]

Hey guys, new to the forum, first post here.
I’ve got a 1995 suburban k1500, 5.7 TBI. Blew a head gasket a few months ago so I decided to put in the garage and rebuild it myself… I’m not an expert but I know enough to be dangerous. When I pulled the heads off I took them to a local machine shop to be checked and resurfaced, passenger side head ended up being cracked so I got a replacement from him. Resurfacing the heads and replacing the valve seals was all I had done to the heads. Rocker arms, valve springs and push rods are all original.
I got everything put back together, set the valves at TDC and BDC per spec, timing set to 2° BTDC, and fired it up. Ran pretty good but had a lifter tap still, so I pulled the valve covers while it was running, backed each rocker arm off until it started tapping, slowly tightened it until it stopped, then gave each one an additional 1/2 turn.
I’ve got an issue with my #2 cylinder exhaust valve. If I tighten it until it stops tapping it’s noticeably tightened further than all the other rocker arms (3-4 turns tighter) and it runs like crap, not firing cylinder #2.
Has anyone encountered this? Maybe a bad valve spring?

 

[scott2093]

set the valves at TDC and BDC per spec,

It's unclear what this means..
Does it mean this?
With the engine in the number one firing position
as determined above, the following valves may be
adjusted:
• Exhaust: 1, 3, 4, 8
• Intake: 1, 2, 5, 7
(Even numbered cylinders are in the left bank;
odd numbered cylinders are in the right bank, when
viewed from the front of the engine).
4. Back out the adjusting nut until lash is felt at the
pushrod then turn in the adjusting nut until all lash
is removed. This can be determined by rotating the
pushrod while turning the adjusting nut (figure 8).
When the play has been removed, turn the adjusting
nut in one full additional turn (to center the lifter
plunger).
5. Crank the engine one revolution until the timing tab
“0” mark and vibration damper mark are again in
alignment. This is the number six firing position the
following valves may be adjusted:
• Exhaust: 2, 5, 6, 7
• Intake: 3, 4, 6, 8
6. Install the rocker arm cover as outlined previously.

 

[Erik the Awful]

Sounds like the hydraulic lifter's not pumping up.

 

[relderado]

It's unclear what this means..
Does it mean this?
With the engine in the number one firing position
as determined above, the following valves may be
adjusted:
• Exhaust: 1, 3, 4, 8
• Intake: 1, 2, 5, 7
(Even numbered cylinders are in the left bank;
odd numbered cylinders are in the right bank, when
viewed from the front of the engine).
4. Back out the adjusting nut until lash is felt at the
pushrod then turn in the adjusting nut until all lash
is removed. This can be determined by rotating the
pushrod while turning the adjusting nut (figure 8).
When the play has been removed, turn the adjusting
nut in one full additional turn (to center the lifter
plunger).
5. Crank the engine one revolution until the timing tab
“0” mark and vibration damper mark are again in
alignment. This is the number six firing position the
following valves may be adjusted:
• Exhaust: 2, 5, 6, 7
• Intake: 3, 4, 6, 8
6. Install the rocker arm cover as outlined previously.

Sorry if I didn’t articulate that well, I adjusted the specified intake and exhaust valves at #1 TDC (top dead center) and then rotated the engine 1 revolution (which I thought was BDC - bottom dead center) and adjusted the remaining valves, just like you described.

 

[relderado]

Sounds like the hydraulic lifter's not pumping up.

That would make sense… what is the fix for that?

 

[Erik the Awful]

Replace it.

 

[scott2093]

it’s noticeably tightened further than all the other rocker arms (3-4 turns tighter) and it runs like crap, not firing cylinder #2.

Sounds like preload is too tight...
I'd try setting it or even all of them again. I goofed up a cold preload my first time. It took a bit of understanding to get it figured out and what it felt like. And I couldn't even tell you if I'd feel confident with doing it on dirty or not new lifters...
At the end of the day, getting zero lash with engine warm and running, then shutting down and setting a preload, works almost identical imo.
Maybe let it settle in while hearing clacking the first time. I found that initially, some would quiet up after a few seconds and then I'd have to loosen more to get it to start clacking again.....some took a few tries like that...
At least until I removed them all and cleaned them. Then everything was very predictable.