w140forlife

hello,
recently my cousins (7-94) s320 its been having some starting issues.
it started by running fine until one morning the car wouldn't start. it would keep crank and crank but would not run . after a few days staying in the driveway would start without a problem would run and drive fine for a day or so and all in a sudden the problem persists again cranking but wont turn over . started by checking fuel pressure but there is none in the fuel rail changed the fuel pump (30a) fuse in the trunk and fuel pump relay and still no difference, tried to test the voltage at the fuel pump plug wire and there is 0 volts with the key in position 2. what would the problem be a bad ecu unit , a bad cps or ignition module.?? and also which one is the LH and ecu in this box. thanks all

oldsinner111

My case no pump or fire.I had been having trouble with my ignition switch now it quit .Mine has 170,000 miles,so it made it that many key ons.
Might be your problem.I don't know if pump has a relay,there are several in the trunk

w140forlife

thanks for your reply. yes there is a 30a amp fuse for the fuel pump in the fuse box in the trunk and also next to that fuse box there is the fuel pump relay as well. changed those both and still no difference no fuel pressure at all in the fuel rail. car cranks and cranks but wont start. if the key is worn out does that have to do anything with the fuel system by preventing the car to no start but only crank?
anyone else experienced this on their s320's?

oldsinner111

It might but I believe in might be the switch,there plastic

CLKTHEO

Hi im having a similar problem did you resolve it? could you pass on any info that could help me please?

Thanks for your time.

Delamoya

Try replacing the fuel pump? My guess would be the pumps have failed.

burgca

If your issue is with a CLK320 M112 engine have you replaced the CPS?

oldsinner111

have you checked fuel pump relay,next to rear fuses,they can go bad.