Bought a used GMC 2500 HD D/A last week. Got a dealer warranty with the truck. When I test drove the truck I noticed a surging idle and an erratic fule gauge. Had the dealer write it up so that those issues would be fixed without any deductible being applied. Fast forward to today. Ran some errands and when I came out to the parking lot there was a nice big puddle of fuel under the truck - at least a quart. Looked to be coming from the area around the front cross member but couldn't get eyes on it to see exactly where it was originating. Drove it home a few miles and let it sit. No leakage. But, when the rain dried from last night I noticed another spot where I had it parked overnight. Any ideas? Could an injector be getting stuck open intermittently dumping fuel into the crankcase and then out an overflow somewhere? I'm admittedly very much a newbie to this so please excuse me if that is a dumb suggestion. As of now it's going back to the dealer in the morning - I just would like to know what I should be looking for in the event I get one of those "Gee we couldn't find anything wrong with it" replies from the service department. I haven't dealt with these guys yet so my expectations are low, lol. Thanks.