fuel injected engine hesitation

[sepulvedac]

I got a 79 Super Beetle fuel injected. Engine was rebuilt less than a month ago. It was g\running great. On the way home my lady filled the tank up and lost the tank cap. We installed a cheapo gas tank that it looks like a bus one. Now the car hesitates while driving and it is getting worst by the minute. Does the fuel tank has to be pressurized? Any way to find out if it is the cap doing this? I checked everything electric and all check out fine. What else to check?

[Randy in Maine]

Get a correct gas cap please.

Could you check the resistance of the Temp Sensor II both dead cold and as it warms up to operating tests. Compare over here please....

http://www.ratwell.com/technical/TempSensorII.html

Could you humor me and also check the aux air regulator and see if that little boot at the end is split and leaking vacuum?

http://www.itinerant-air-cooled.com/viewtopic.php?t=6867

[Jaygyver]

Your tank needs to be VENTED. Not pressurized.

[zeroman]

the stock super gas cap on the FI engine doesn't have a vented cap does it?

I had horrible hesitation when I knocked a hose off the junction that's attached to the engine compartment on the drivers side hinge. The hose still was hanging like it was attached.. but it wasn't. It would barely run. Maybe if one is cracking would do that?

[sepulvedac]

new cap did the trick. No more hesitation. she drove from Pipe Creek,TX to Galveston,TX (302 miles) without any problems at all.
Thanks.