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Matt
Matt, Mechanical Engineer
Category: BMW
Satisfied Customers: 22258
Experience:  BEng hons Mech engineering, in auto industry 22 years
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bmw 330d sport auto 2002 car starts perfect every morning.

Resolved Question:

bmw 330d sport auto 2002 car starts perfect every morning. after a short journey when you switch off it will not restart. R A C MECHANIC said it was the fuel pump which has been replaced, but the problem is still there. If left over night it will start as normal. Please can you help.
Submitted: 3 years ago.
Category: BMW
Expert:  Matt replied 3 years ago.
Hello

thre are 2 electric pumps on this car, the 1 in the fuel tank and another underneath the car

the one under the car is more importantso if that hasn't been replaced then consider doing so

it’s also worth considering fitting a new fuel filter as if only slightly blocked this can lower fuel supply pressure and choke the main pump, the pump will be more sensitive to this when its cold as diesel thickens considerably with low temperatures.
and it may have developed an air leak on the fuel supply pipe from the tank to the engine. If a leak has developed on the fuel suction pipe then air entering the system will air lock the pump.
Try having the ignition on then crack off / loosen each injector pipe in turn while cranking the engine and getting an assistant to operate the primer. This will expel air from the injection side and the engine should fire up. The problem will be cured by checking the supply pipe along its length for signs of leakage and repairing any you find.
If you daub each pipe joint with heavy grease and the issue goes away then wipe the grease away one at a time to highlight the problem joint
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