i hava an 89 astro and the engine while i am at a stop the engine will run really rough but normal acceration it does fine i have put plugs wires cap and rotor in already replaced all of the bad vaccum lines and coolant temp sensor(one that sends signal to the ecu) oh and someone before i owned it disconnected the egr valve and jb welded the port on it shut and suggestions on where to go next?

 

I think I would suspect a leaking injector. Pull your plugs and look for one that is burning too rich. Just an idea.

 

checked those and do not seem to be leaking at all

 

Maybe you should get the rid of that bad EGR valve and replace it with a new and see if that makes any difference.

 

hello i have a 2000 astro
my van was shaking the hole dash in gear at idle
but it ran fine off idle
i replaced both motor mounts and the tranny mount
now it is smooth
i had thought it was running ruff
but the shop i took it to showed me
he jacked up the motor and the shaking stopped
hope this may help

 

i tried to replace it and did not change too much my motor mounts looked to be in really good shape i could not hardly move the motor at all any other suggestions