The problem could be a shorted park netual safety switch . Do you know what a wiring diagram is ? It shows all the componets involved in a electrical circuit ! You IGN.1 fuse 40amp , GM calls it IGN A fuse 40 amp . It feeds the ignition switch and pin 30 at the starter enable relay .When you turn the key to the start position it sends B+ voltage to #8 crank fuse , located in the I/P fuse box ,from there it goes to the park netual safety switch , to pin 86 or 85 of the starter enable relay ! If you pull the relay out of the fuse box an look on the bottom you will see this four set's of numbers ,30,87 & 85 ,86 You can test at the fuse box where the relay plugs in . Here is a video on how to test . The guy presenting the video uses a horn circuit , but it works the same way . It happens a lot , the park netual safety switch shorting out . It may or may not be the problem . VEHICLE RELAYS Operation Diagnosis
Here is a web site for free wiring diagrams
http://www.bbbind.com/free_tsb.html Enter your vehicle info . then under system click on engine , then under subsystem click on starting . Then click on the search button an a link will pop up , click on it .You will see all the componets , connections , wiring colors etc... for the starter circuit for your vehicle .
exhaust resonance is unlikely
vibration is caused by something spinning that is out of balance
it can also be from a misfire or a mechanical problem
considering the mechanical problems
harmonic balancer - replaced delete reference unless loose bolt
loose clutch pressure plate --no information as to auto or manual--possible
cracked flex plate--no information as to auto or manual ---possible
failing cam shaft lobes --cam nobes wearing off causing valve timing problems --very possible
faulty hydraulic lifters --pumping up and holding a valve off the seat -possible
hydraulic follower failure --excessive valve clearance altering valve timing --very possible
ignition timing too far advanced -- tune up should have checked that but is a possibility
failed water pump bearings --noisy but a possibility
viscous fan hub ( if not electric fans )-- a distinct possibility--bearing failure and fan running off center-off balance
injectors --- any injector squirting but not the same amount as the others will cause a harmonic unbalance --possible
except for the cam shaft as mentioned , the engine has done 30.000 miles so any fault in the rebuild would be shown up before that mileage was done
drive line problems ---unlikely as you state it vibrates when stationary and that confines it back to the engine and transmission
only parts spinning are the engine parts and the input shafts , torque converter or clutch
if you want to check timing,, place timing mark to 0 and remove distributor cap look if rotor point to number 1 cylinder if not timing belt problem
hope it helps
IF your ****** was removed and re-installed there is a good possibility that there is a problem withe torque convertor. either it is not installed or seated properly or the weight block welded to it may have come off. Also your flex plate ( the part that your torque convertor mounts to) may be warped or bent during re-installation Hope these ideas help you out..
you may have a couple of blown fuses. dash lights are usually fused separetly to other vehicle lights. you might also want to check your dimmer switch on your left hand dash, it will make them go out if turned down. if the lights have auto memory, check to make sure it's set correctly. hope this helps.
You probably have a damaged flywheel. Take the starter off and using a socket on the front pully bolt, rotate the engine and look in the hole where the starter goes to inspect the teeth on the flywheel. If the teeth are damaged, the transmission has to come out to fix it.
