S80 Difficult to start

Well, it really depends on what kind of car you have. If it's an older car with a carburetor (pre 90s), then this is normal. Let's assume you have a newer, fuel injected car.

I would start with a basic tune-up. Your car isn't starting quickly, which is a common indicator of a car being out of tune. Change the spark plugs, distributor cap and rotor (if your car has them). Depending on the condition, you could also change the spark plug wires.

Additionally, you should run some kind of fuel system cleaner through the gas tank. I prefer Seafoam. If you have 8 or less gallons in the tank, add one can. More than than, add two cans. It would also be beneficial to change the fuel filter.

All of these things can be done DIY, or you can have it done at any shop.

If that doesn't solve the issue, you may possibly have an issue with your fuel pump, fuel pressure regulator or fuel injectors. Start with the cheaper tune up, though.

First off.... You have to make sure it IS getting fuel. Are you sure the fuel pump is getting 12volts... the fuel filter is installed in the right direction? Have you disconnected the supply line at the throttle bodt to verify fuel pressure and volume? If it starts with ether... there is definately a fuel supply issue from the tank

You need to run an engine control module scan for fault codes Known as an OBD2 fault code test.. Autozone and others do this for free. If no fault show then hook up a test fuel gage the next time it stalls and see if maybe the fuel pump is failing.

Did you change fuel filter??

Does the fuel pump relay come on?

Please check the fuel pressure pump in the fuel tank.
It looks like in tank filter is blocked or the fuel pump is weak.

I'm assuming you mean the injector pump and not the fuel lift pump. I would recommend if the fuel injector pump is proved to be the fault to look at Ebay for a replacement. there are thousands of these engines broken for spares. Fitting the pump can be a bit tricky. If it's the lift pump you need to remove the fuel tank as the pump is fitted on the top side of the tank and is an internal unit, Best done when the tank is empty. Hope this helps as i'm sure your landrover will still be running when a Jeep is in the dump. All the best.

Possible leak or failure of gasket or a possible damaged fuel pump body, if theis fault is quite evident then you must change the pump or have the line checked once again to confirm the fault of the pump or the fuel lines to and from the tank.

You can't just remove the battery and replace it on this mercedes. you have to enter the proper code on the dash by the radio. take the vin # into the dealer and they will give the code

If it is not a fuel problem, then it has to be either not enough air or an electrical starting problem. Try starting it without the air filter in place. It could also be a bad plug or more likely a bad spark plug or coil wire.