2000 Volvo s70 awd crank no start after fuel pump replacement

[IanDeez]

I recently replaced the fuel pump on my s70 because it seemed to be running lean while driving and driving rough but rich at idle with gray and black smoke coming from the cat and a strong smell of gas and rubber now that the fuel pump is replaced and was installed correctly along with a new fuel pump relay I get a crank no start with no pressure at the fuel rail I've checked all my grounds and wiring between the relay pins and fuel pump connectors and when power probed I get the 12.4 volts I need but running off just the battery with the new relay in i am only getting around 8 volts at the connectors

[Vova585]

So you have fuel delivery issue.
From simple to hard
1.verify you have gas in tank(I am not joking or make fun here. If you 100% sure gas is there than ok)
Install old fuel pump relay and try to prime pump/start the car. No noise from the pump despite old relay-ok.now take test bulb(i like H7 since it is easy to connect wires to prongs and connect wires to it. On one wire install 10 amp fuse in line(optional). Now remove old/new pump relay and create a "bridge" between 30 and 87 posts. Can use a piece of wire with male connectors and stick them between 30 and 87. (Can add in the middle 10amp fuse). Now with your H7 bulb check between big wires at fuel pump connector- bright light, ok great, supply is solid until here. No light/dim light- look what side is weak power or ground via substitute from chassis ground ar battery post. Based on findings repair broken/defective wire.
Solid bright light-. Remove the "bridge". Open the fuel tank and look if any of the connectors are broken. What pump you used? (Oem, bosch?). Sometimes they are broken from the box. So look at wiring to the pump itself and test with test light(h7, open car, preferably outside of the car, no fumes...safety). If light is bright and pump is not working- congratulations your pump is junk. Put in the old pump and old relay and try to start the car. If the car starts- great. Now check the pressure in the fuel rail and see what it is. Try to apply gas pedal rapidly and see if it is able to hold steady at 3bar vs dropps down significantly....