noise under air filter

[Scott E Robbins]

Hello all,
I have a friend who's 17 year old daughter has a 1987 Accord LX, she has been having trouble with it stalling on her and not starting until cold, although sometimes it will not start at all. I looked at it tonight and it would not start, so I checked the plug wires, took off the air filter cap. I had her turn it over to see if I could smell gas and it started up?? filter is clean. The car ran fine, but there is a tapping noise comming from under the filter area. it is not the valves. Does anyone know what this is. Is there a fuel pump there? I did not have time to pull anything off the car to look into it more. The noise changes tempo this the rpm of engine. The car has over 170,000 miles on it, but ran fine while I was there.
Any Ideas would be a help, they dont have any money to have it looked at by dealer and her 17 year old boyfriends keep giving her bad advise (Its the alternator, its the battery, or the oil is supposed to go to the top of the stick.)
Thanks