Fuel check valve confusion...

[Rus]

Hello!

I have recently replaced the fuel pump in my 535iA with a Bosch unit that I purchased from BMA. In the part description, BMA states: External Check Valve Does this indicate that the check valve is built into the pump? The pump seemed identical to the one I removed from the car. The reason for my concern is that the engine takes about 2 seconds to start, which seems a bit long for a fuel injected engine. So far I've replaced all the vacuum lines, intake boots, cleaned the AFM track (as per instructions from this site), replaced everything but the coil in the ignition, and replaced every bit of fuel line. So the question is: Do new pumps come equipped with the check valve or should I install a separate one? If its not a check valve issue, I guess I have a leaking injector that depressurizes the system. All comments welcome. Thanks in advance.

Best regards.

[Blitzkrieg Bob]

That’s not too bad, leaky stuff usually takes several cranks to get going.

Leaky injector will make the motor flood, noticeable on warm/hot starts..gotta floor it to get it to start. Gas smell too.

Leaky check valve takes several cranks to get going, as the pump only runs when the crank is turning repressurizing the system.

[Rus]

I guess I'm just too used to my engines starting from just a bump of the starter. My carbed 4-cylinder Honda catches on the first turn. The big 6 isn't having any issues in terms of power or flooding, so I'll just live with it. It has yet to force me to crank the engine over twice to start. Thanks for the reply.

Best regards.