Chevrolet Repair: ses light keeps comming on, service engine soon light, diesel fuel

Question
i own a 94 chevy 6.5l turbo diesel. whenever i'm going uphill or passing on the freeway the service engine soon light comes on until i let off the throtle and then push it down again. also i've noticed that after my first drive in the morning to work when it is parked, there is a rainbow looking patch that i can see after it has rained that stretches out past the front wheels, i'm pretty sure it is diesel, what i am wondering is if it is loosing a lot of diesel because it isn't actually making a puddle, is it dangerous, and do you think the two problems are conected. thanks

Answer
The two problems could surely be connected.
Not a safety hazzard, as far as catching fire is concerned, but I would sure want to find it.
Look on top of the engine, and see if there is diesel fuel down in between the heads.
A fuel filter or injector pump line may be leaking.

Van