i changed my rims (lucky it was in the garage), when i went to start it all it does is crank but won't turn over. first, i already checked the battery, it has fuel, tune up has been done, fuel filter has been changed. i did nothing to the engine except an oil change about a month ago, everything i listed was done a few months ago before the summer. all i did was take off the rims and put the new ones on. problem is i don't hear the fuel pump activate. i switched out the relay and still nothing. hit the schrader valve and there's no pressure no fuel came out. i do have an intermittent problem with the ignition switch but it hasn't acted up in a while. about a year ago my truck did the same thing where it would crank but would not start, i messed with the steering wheel tilting it up and down and all lights went on and it started up. hasn't given me a problem til now. it cranks and will not start, my question is would the ignition switch cause there to be no fuel pressure and the pump not to activate. or is the pump going out now or the fuel pressure regulator going out. i do most of the work myself but i take it to somewhere if i don't know how to do something or i don't have the equipment. it ran fine earlier no problems, started and ran fine took it on some errands and came home and changed the rims, did not touch the engine at all. it's a 98 oldsmobile bravada 4.3 engine runs like a champ til today. i put some of that throttle spray in and it starts but dies out then just cranks. thought there was no spark but there is and the battery connections are good also i took them off and check and re tightened them. i'm at a loss, is there any way to maybe jump start the fuel pump to maybe get it to a shop if i change the ignition switch and it turns out not to be the problem. i bought one to change it out but had no time, and since it hasn't given me any trouble i figured i wait til this weekend since i have my vacation to do the work.thanks for the help. hopefully i won't have to take it to a shop