A4 stalls after running for 5 miniute

[sail550@yahoo.com]

A4 Starts fine, runs for 5 minutes then dies.I checked elect fuel pump seems to be operating. Opened fuel cap no vacuum or vapor lock symptoms, changed racor fuel filter, replaced gas in tank ( pumped out old fuel replaced with new fuel ) did a visible inspection of fuel lines but cant see a reason why this happening. Note that primer bulb from fuel tank, once primed stays firm, then you can run eng. for 5 min. until it stalls then bulb is soft, I must reprime bulb for eng to run for another 5 min. cycle. but it will stall again. I'm stumped. Anyone else ever experience anything life this?

[Dave Neptune]

Welcome. First get rid of the squeeze bulb, they're illegal. Sounds like the fuel pump is dead or you would not need to pump the bulb again.

Electric or manual pump?

A fuel pressure gage will tell all. A good idea to install one.

Dave Neptune

[capnward]

This has not happened to me, but I have some ideas. First, see Don Moyer's video on unexpected shutdowns, if you haven't already.
When it dies, does it sound like you turned off the ignition, or like you had turned off the fuel flow? There is a slight difference.
Seems to me it's a fuel issue. 5 minutes is about as much gas as the bulb would send into the carb. I don't have a bulb, just a mechanical fuel pump with a hand bail you can use to pressurize the fuel line. Bulbs are not approved by the Coast Guard except for outboards. A fuel pressure gauge would help. How did you determine that your pump is operating? There may be crud in your inline filters restricting flow. Or there may be a blockage in your carb main jet. Was there water in your Racor when you took it out? Your water separator filter may have too much water in it, but since it's new I doubt it. Since you pumped out the old gas, you probably don't have too much water in the tank. Splashing new gas into the bottom of the tank may have stirred up any crud left there. You may have a small leak in a fuel line connection, not enough to spill gas but enough to pull air into the line. Electrical fuel pumps are less able to handle leaks like that. Seems to me if the bulb is soft, you have little or no fuel pressure from the pump. Try blowing through the fuel line back into the tank until you hear it bubbling. Not a pleasant task, but it may dislodge (perhaps temporarily) a blockage in the pick-up tube.
If you are using ethanol fuel, problems with clogs in the fuel line or carburetor are more likely, in my experience.
Good Luck, and please let us know how you fixed it.