Not sure if this belongs here or in the General category but here goes. I have an 87 Duke 5spd. The car has been great to me. No issues after getting it on the road last year. Today after 25 miles of highway driving I got off and pulled into a gas station. I filled up, adding an extra .3 gals of fuel after the pump shut off. When I started the car the RPM's went to 3k and stayed there. I only work a mile from the gas station so I drove it to work and parked it. I assumed my egr had come loose. It did this once last year and acted the same way. I went out at lunch, checked the egr and it was tight, I couldn't see anything out of the ordinary. All soft vacuum lines were replaced last year. I started the car and it was fine. 2k rpm, drop to 1500 after 5 seconds, 900 after a minute or so. Could force feeding the tank that .3 gals of extra fuel some how cause this to happen? It sure acted like an exhaust leak... a fairly large one too. Thanks for your time guys.
Fiero gas tanks are small, so it's tempting to get as much fuel in it as you can, but don't do it. What may have happened is fuel was siphoned up the vapor line to the canister, and into the intake manifold. The bad part about that is liquid fuel will ruin the charcoal in the canister....so if you notice increased fuel smells in the future, that is probably the reason.