Fiesta problems

[thepoet]

I have an XR2 (1988) engine in a Quantum 2+2 kit car. Recently had the fuel pump changed and the car was OK when first stated, then it cut out and wouldn�t start again. The garage took off the air filter and with a hand over the carb, it started first time and ran well. Air filter back on, wouldn�t start. The garage tell me that the breather sytem and the vacuum tube are OK, but can�t explain or solve the problem. Any suggestions??

[chevrolet1.8]

i'm no expert but is the gasket under the carb ok and not leaking air in? if the mechanic took the air filter off and put his hand over the top of the carb was he pushing down on the carb and so sealing any leak. try starting it with someone pushing down on the carb with the air filter on and see if it makes any difference. good luck