When I fuel up at some, but not all, gas stations, the automatic shut-off clicks off repeatedly, so I have to keep restarting it. It seems like a few tenths of a gallon will go in and then the handle will click off. Any idea what causes that?

That is the way the pump nozzle is made, to shut off when the tank or in your case the filler neck has fuel in it. It shuts off, the gas in the filler neck drains into the tank. You then have some more space and can pump a little more gas in. Why it does in some and not others is dependent on how the nozzle was manufactured.

Turn the nozzle upside down when you are filling. Sometimes sideways, depends on the particular nozzle.

http://science.howstuffworks.com/question25.htm explains the nozel.

Some nozels foam the fuel more than others going into the tank. The foam is all it takes to trip the nozel.

You can try turning the nozel as mentioned. Also try holding the handle up so the fuel shoots down the pipe farther before hitting the wall of the tubing.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurasic Park)

The Ogre's Fiero Cave (It's also at the top of every forum page...)

With My S10 theres one gas station that does that, drives me nuts! The thing that sucks is this place always has the cheapest gas!

Jason

Most likely these nozzles have the gas fumes collection device on them. I've noticed that those nozzles have more back pressure causing the feedback to trip the overflow shutoff. Back in the day when the Fiero was designed they didn't have such devices so there is probably more pressure coming out of the filler neck and when coupled with the fumes collection mechanism, it trips the overflow cut-off. I thought the EPA mandated those collection hoses but now that I think about it, not all stations have them. Of course all stations will now be equipped with backup electrical generators though...

I've run into that problem before. Especially the pumps with vapor recovery. They click off real easy then they have the nerve to post a message saying "Do not top off your tank". Hello,,,, this is a Fiero and we need every drop we can get so I'll nurse it in til its topped off. Another fine mess the the EPA got their ample nose in where it should'nt be.

There are several types of vapor recovery nozells running around. Some look almost like non recovery ones.

The way the nozell works... pressure in the neck doesn't matter. The usual problem is fuel hitting the top area of the pipe where the tank vent passage is trying to unload fumes. This makes the foam splash around the nozel end where the sensor opening is. All it takes is a little foam hitting that opening to kick the pump off, especially if the nozel is set on the sensitive side as ones on many high speed pumps are.

That brings me to another point... many of the larger chains use a faster pump to keep people moving. These are capable of filling some cars a little faster than the pipe can easily drain.

Holding the handle up so the fuel discharges more downward into the pipe can help with both problems.