I just had my diesel injector pump, vacuum pump, lift pump, and alternator replaced and I am noticing a problem when I start up my truck. When I do a cold start after it is sitting a while it starts up fine, but when I drive for 30 minutes or longer then turn it off and then start it up again 20 minutes later it takes a while to crank over about 3 to 5 seconds. Any ideas what is wrong?

 

It sounds like you may have a fuel pressure issue.