Hello guys I'm new to this site any help would be appreciated. I have a 01 Thomas School Bus 3800 dt466e my first question is I lost the key can I just replace the ignition switch with another one from auto parts store or what do I need to do. My second problem is I bought my bus a couple weeks ago the first one I've ever owned hoping to convert it the guy said the motor was just overhauled I thought it was a good deal till the next day I drove it about 20 or 30 miles I drove it hard I came to a stop it shut off on me I sprayed ether in it it started up idle good for a couple minutes I put it in drive it shut off again spray ether in it hit the gas put it in drive made it to my tire shop .i start it up after with either.i left next day would not start no matter what turns out it was a pressure release valve I replace the pressure release valve ran fine drove it 20 or 30 more miles just to make sure it was alright came to a light it shut off had to spray ether in it made it home let it cool down it would start run idle fine I don't know if this has ever happened to anyone else I had a school bus mechanic that fix the p r valve tell me to change the fuel filter that there was no secondary fuel filter system on this truck that it probably just sat and it needs a filter but I was just wondering I was going to do that tomorrow but I lost the key if anyone can help me please let me know thanks in advance