How do you replace the struts on a 1991 chevy lumina?

the rubber insert is what stops the knocking sound over every bump
it will eventually cause mount failure
take it back and have them do the job properly

Here's a link to your struts,join the site,it's free,then you can use their repair guides like me.

You need to have a floor jack and a couple of jack stands. Two bolts hold the strut to the rear wheel/brake assembly and I believe it is one bolt in the trunk. I changed mine about 3 years ago. You shouldn't need any special tools for this. You should have a 4 wheel alignment performed after the struts are replaced. The two bolts on the wheel assembly control the camber of the tire, I would recommend that you look at where the old bolts were when you tighten the bolts down for the new strut.

You have to remove the torque strut, at top and
your front/radiator side and either pry the engine
to the front of car or buy the tool that goes into the
strut mount for that purpose. It draws the engine away
from firewall

If it is the same as my 1991 lumina it will be mounted to the left strut tower under the hood. There should be a fuse and a relay.

try unpluging your torque converter

a few things tires out of balance-bad tire-rim bent-shock/strut bad-worn or loose front end component-ball joints-bearing/hub---if bad enough to shake/shimmy u should be able to see or feel problem under front end jack up car and with wheel on move side to side than up and down than in and out when u do this if u hear a clunk or see a part move that shouldnt [tie rod connection/ball joint etc] than u found problem

Had fule pump and filter replaced, 3 months later, same problem, car will not start, replaced Relay Switch, still wont work. any suggestions?

This model doesn't have shocks. It damps bouncing with McPherson struts. The front struts can have a new cartridge installed while in place, but it's an involved process. The rear struts have to be removed to replace the struts -- a more involved process that requires some special tools. The struts last a lot longer than shock absorbers, but are not nearly as easy to change when the time comes.

is it a 3.1v6 ? check/replace your plgs wires check/replace the egr valve