The bike repair biz in general is less than lucrative. Running a mobile bike repair business is pretty tricky - lots of people have tried it, few have succeeded. The big thing, as it is with most new businesses is marketing. At least with a shop people will ride, drive, or walk by and see the location. I tried running my own little mobile bike repair business once. I used an Xtracycle rig (see www.xtracycle.com) so that I could carry a bicycle repair stand and lots of tools but not have any gas, insurance, or registration to deal with. The problem with that setup is that you are limited in what parts you can carry and more often than not, the customer has no idea what kind of bike they have or what components are on it. Which makes it quite hard to anticipate exactly what you'll need to bring. A van with a well thought out stock of parts would be better and you can get there faster, but of course the overhead will be much higher. I did manage to get some business solely by having a website, however, the search engines changed their algorithms so that the most relevant sites do not come up first. For instance, if your business was located in Portland and was called "Bob's Mobile Bicycle Repair Service" and someone typed "Portland Bicycle Repair" into a search engine, it used to be that you'd have a fairly high chance of coming up first. Now you'd be buried way below a bunch of irrelevant garbage since the most important thing is now how many sites link to yours rather than how directly it matches the inquiry.

Regardless, if you want to use the van for a repair service, be prepared to spend tons of money on advertising, spare parts, and painting a nice big logo on it. Also, commit to the thing full time and have lots of money saved up so that you could last quite a few months without any income. If you are willing to do that, then you have a small chance of success. Otherwise, sell the van and buy more bikes.