328 engine flooding after sitting for a few weeks.

Did you send your fuel injectors out for testing and cleaning? Could it be leaking fuel into the cylinders?

 

My 328 GTS has got the problem of engine flooding after just switching the ignition key on, the fuel pump doesn't stop working

 

Sounds like you have two problems as even if the fuel pump runs with only the key "on" that shouldn't cause engine flooding. Please indicate what version 328 you have -- US or euro?

1. For the fuel pump running with just the key "on" = check to see if the safety switch is unplugged:

Image Unavailable, Please Login

If it is unplugged that will cause the fuel pump to run with just the key "on". Often this is applied as a quasi-fix for difficult warm restarts when the real trouble is that the system is not holding residual fuel pressure after engine shutoff (due to a bad fuel pump outlet check valve, a bad Accumulator, or a bad Control Pressure Seal in the Pressure Regulator of the Fuel Distributor).

2. For the flooding, the first diagnostic thing to do is unplug the cold start injector and measure the voltage between the two terminals in the harness connector with just the key "on" (engine not running) = should be 0V (if it is +12V DC = most likely a bad thermo-time switch). If it is correctly 0V, the next diagnostic step is to measure the cold and warm control pressures of the WUR and compare to the WSM specs.

 

Mine is a US spec , i have sorted out the flooding issue which was due to the safety switch , the present situation is that the vehicle would crank perfect but it won't start unless and untill I keep adjusting the airflow meter down with my hands , is it caused by a any valves in the fuel distributor or is it because of the wur

 

The flooding issue has been sorted , it was because of a bad safety switch , now the present scenario is that the vehicle cranks very well but it doesn't start unless and untill I start to adjust the airflow meter plate and with the airflow meter held down if i try to operate the throttle and remove the load from the airflow meter it comes back and the engine stops .
Would be because of too much pressure inside the fuel distributor system .
And I bought this car at an auction which was in a no start or no crank condition , it is a US spec

 

It can be a symptom of the WUR having too high a cold control pressure (which reduces the deflection of the fuel distributor plunger and keeps the FD slits more covered = supplies less fuel). When you hold the airflow metering plate down, you are artificially deflecting the fuel distributor plunger which opens the FD slits more = supplies more fuel. IMO, you should get the following items measured (these are the basic initial diagnostic steps for setting up any K-Jet injection system done with the engine not running, but fuel pump running -- i.e., with the key "on" and the safety switch unplugged):

1. Measure the regulated fuel supply pressure -- ensure in-spec.
2. Measure the cold control pressure from the WUR -- ensure in-spec.
3. Measure the warm control pressure from the WUR -- ensure in-spec.
4. Measure the fuel pressure at engine (fuel pump) shut-off -- ensure in-spec (not needed for engine running behavior, but can impact warm restarting and is basically a free measurement since it's the same as doing #1).

If all those items are OK, then the other possibility is that your mixture adjustment is just set way too lean (and that would be the next thing to adjust if #1-4 are all OK). Another good diagnostic step is to unplug the cold start injector and connect a 12V test light to the two terminals in the harness connector. During the first cold cranking attempt, the test light should illuminate for a second, or two -- this would confirm that the TTS is working, and the cold start injector would (correctly) squirt some extra fuel during the first cold cranking attempt. On a US 328, you should also check that the frequency valve is buzzing/vibrating (can be done just by touching it) whenever the fuel pump is running -- this confirms that the Protection Relay is working and the injection ECU has +12V to operate (this is important because the frequency valve is also used to provide extra enrichment during starting).

Good Hunting! It's always difficult bringing a car back from the dead because not only does it have something wrong, but probably every adjustment has been mucked with. This US 328 document from FNA has the fuel pressure specs for #1-4:

https://www.dropbox.com/s/e5pjuyiyo56vb13/328 tech specs and service bulletins.pdf?dl=0