Festy runs rough after a exhaust flange gasket replaced

[DaleInTN]

Ok

Would a bad lifter cause the motor to run rough? I replaced 2 of them and was going to try to wait to replace the other 6, but she was clicking pretty bad. The lifters have 293,000 miles on them, if they are worn out bad enough, would they prevent the valves from opening completely?

I was also wondering if the springs on the rocker arm shaft were not properly installed and the rocker arm could slide out of place, could that explain the running on 3 cylinders and then running on 4?

Thanks, I'm going to replace the other 6 this weekend and be sure the springs are right, I'll report back.

[Snail]

If the lifter is siezed it could cause a problem, but it would likely be worse at highter rpm. If your rocker arm is moving, a rough idle would be the least of your problems. If it runs good at every step besides idle i would suspect a sensor, or an intake/exhaust issue.

[Pu241]

I'm thinking vacuum leak in 20 yr old brittle tubing, which might have got pinched/bent then cracked while you were working on the exhaust.
Just a possibility.

[DaleInTN]

Update

I replaced the other 6 lifters (8 in total) now. Before I took the rocker arm shaft loose (on the one I had already replaced 2 lifters) I noticed that 2 of the spacer springs were stuck under the bolts. I am assuming that this allowed one of the rocker arms to slip out of position and not open the valve fully. I replaced all the lifters and was very careful to make sure all springs were not tightened under the bolts and she runs fine. No miss, no hesitation, no problems. I think I dodged a bullet with those springs! Anyway, she runs great and much, much quieter. Thanks for the input guys!

[Snail]

I am glad your car is good to go now.