Hi i have a lancia delta 1.6 16v 103hp ( 182a4000) same engine with fiat bravo/brava/marea1.6 16v .I had a problem with the original fuel pump walbro mss 071 and left me on the road..I looked to find a new one original but they stopped the production of this pump. So i started looking for an aftermarket fuel pump as up to now i have changed 4 diferent fuel pumps and neither of them works properly .the pumps who i had tested are: a new hoffer 75063 , a new walbro ess452 , i tried a used black bosch pump from dedra and now i have a meat&doria
7506201 inside the box i found a walbro AOU 202-9 (i cant understand why in a meat &doria box is a walbro pump). with this pump i am 2 months now it works but my car wont accelerate too good especially in low rpms and in hight rpms i saw difference .
Anyone knows what is the correct aftermarket fuel pump to make this car work properly?

Something with pressure regulator inside the unit.
Bravo/brava/marea 1.6/1.8/2.0 have the fuel pressure at 3bar (>120l/h) so fuel sender units from those should do for parts or something aftermarket with same specs.
1.4 wont do as it has lower pressure.
1.8 has same mss071
older 2.0 has bosch 0580453408
1.2/2.0 have bosch 0580313011 (complete unit)

Are you sure your pressure regulator is working correctly?
Garages should have tools to test the pressure from the line.
Also measure the voltage the pump is getting when it is running, bad contacts might cause voltagedrop and pump might not output enough pressure.

Yes i had changed the fuel pressure regulator with a new one original (webber mareli) and measured the fuel pump pressure in a friend's garage with a gauge the pressure is 2.6 bar when the engine is running idle.Injectors are all at 15.8 -16 ohm. (i think its ok) and took them for an injection cleaning
Other things i had changed in that car is a coil pack ,sparks, spark cables , air temprature sensor , oxygen sensor and a used original catalytic converter in good condition. Last week i went to lancia dealer and they took diagnosis with examiner tester and no fault found. What other things i can see?

Αfter many days problem still exists i dont know what fuel pump to buy because i had spend money in previous pumps and i have a little disappointing with the these pumps .anyone can tell me a workable pump ?? or a name of fuel pump manufacturers you've tried successfully? or your opinions about this thing

Did you measure the voltage at the pump when it is running?

And this is the engine with pastic upper intake manifold (older aluminium one has regulator on the injector rail and a returnline to tank)?

How does the engine behave, does it lose power and run lean, or does it just cut out?

yes i have the old one with aluminium intake and the return line to the tank and i had changed the fuel regulator with a new one weber.the engine looks like it has delay when accelerating and has difficulty to accelerate over 120-130 km is shown as having power loss.
Also i hear a metallic sound from the injectors when accelerating hard especially in high rpms above 3000-3500 rpm like it dries from gasoline?