'99 3.1L Teardown Question

[Jogasz28]

Well, after way too long, I'm finally back on replacing the Head Gaskets and on up on the '99 MC.
I'm now at the point of having the upper and lower intake manifolds removed.
I know I should identify which pushrod goes where, but should I also identify the rockers and nuts?
Is the Factory Manual's valve setting procedure the best way? Or should I find each lifters mid lash point (a bit time consuming).
And speaking of lifters, can I bench test them with a pushrod?
When I rebuilt my '95's 3.4 I sent the Fuel Injectors to WitcHunters to be Tested/Repaired as required. Are they still the best Injector rebuilder to use?

[prophiseer]

Not sure on the fuel inj. TBH, my suggestion would be to replace the factory ones with some slightly fatter aftermarket units (i.e. Accel). Going up to 17# will give the PCM a little more room to work with, and the amount of flow variance between injectors will be less than the factory units.

As to the valve lash, I've never had to set that on the roller styled cams - tightening the rocker towers to the factory torque spec is enough. The only components you need to keep in order are the pushrods, as the intake and exhaust lenghts are different. It's a good practice, though, to keep all the comonents for each cylinder in order . . .

The best method for testing the lifters would be to check them with the valve train still intact - if you can let the motor sit overnight so the lifters bleed off a little, trying to wiggle each rocker up and down against the pushrod should spot any failing lifters rather quickly (there will be some play, whereas good units should have none). Trying to bench test the roller lifters, though will prove a challenge. For starters, the bottom has a roller for riding the cam lobe - which would require the lifter to be held in place with a bench vise to be tested. If you're careful, and wrap the jaws of the vise and do not apply too much pressure, you should be able to put just enough pressure to check the top of the lifter - if there's any slight play in the top of the lifter by hand it should be considered bad. The top plate should be able to stay firmly at the top with light-moderate pressure being applied.