Hard to start, rough running, loss of power and engine dies while turning

Tiny
TOLLEY81
  • MEMBER
  • 1999 CHEVROLET TAHOE
  • 5.7L
  • V8
  • RWD
  • AUTOMATIC
  • 200,000 MILES
I had to adjust all the valves on the truck, after doing this it started fine but ran very rough and sluggish. When I go to turn or stop it dies and is very hard to start back. What else could be wrong?
Do you
have the same problem?
Yes
No
Thursday, May 21st, 2015 AT 4:30 PM

4 Replies

Tiny
CARADIODOC
  • EXPERT
What led you to thinking the valves needed to be adjusted, and describe the procedure you used.
Was this
answer
helpful?
Yes
No
Thursday, May 21st, 2015 AT 5:08 PM
Tiny
TOLLEY81
  • MEMBER
All the lifters were very loose and rattling very bad. I got directions on here on how to adjust the valves. I will upload pics on the info I downloaded. I don't know if the pics are gonna be in correct order or not but I started with it in the #1 firing position, done what it said and turn crank to #6 firing position and done the rest. After that it started up but ran like it was misfiring or something
Was this
answer
helpful?
Yes
No
Thursday, May 21st, 2015 AT 5:17 PM
Tiny
CARADIODOC
  • EXPERT
I'm surprised to see such a detailed set of directions. These should be a standard GM cylinder head with a common and simple procedure.

What works the best is to remove the valve cover from the first head, fashion a drain shield from a piece of cardboard so the spraying oil runs back into the head, then adjust the valves with the engine running.

Start with the first adjustment nut and back it off slowly. You'll hear the lifter clatter for a few seconds until it slowly pumps back up. Keep slowly backing the nut off until the clattering doesn't go away. Tighten it just enough for the clattering to stop. That's the starting point. Now tighten that nut one quarter turn. You'll get a noticeable misfire for perhaps as much as five seconds until that lifter bleeds down. Tighten the nut another quarter turn and do the same thing. Keep track of how far you're adjusting that nut. After about two complete revolutions, maybe three, the misfire won't go away because the lifter is fully-collapsed and that valve is being held open. Back the nut off just to the point where the misfire clears up. That's the second reference point. Now back the nut off exactly half as much as you turned it down from the starting point. If you went a total of three turns, back it off one and a half turns. That will put that lifter exactly in the middle of its range. There will be plenty of self-adjustment range now that the lifter can bleed down of the push rod gets hot and expands, and it can pump up when parts are cold and shrunk.

Do that for each valve, then do all of them on the other side, and you're done.
Was this
answer
helpful?
Yes
No
Thursday, May 21st, 2015 AT 6:24 PM
Tiny
TOLLEY81
  • MEMBER
Okay, thank you. I will do this first thing in the morning.
Was this
answer
helpful?
Yes
No
Thursday, May 21st, 2015 AT 7:07 PM

Please login or register to post a reply.

Recommended Guides