I changed the fuel pump already and the rcm but still no start only cranks anyone have any idea?

 

Crankshaft sensor comes to mind, around $30 and if your handy with tools it's not too hard

 

I already changed the sensor as well, I even bought a new rcm to see if that was the problem still only cranks but no start

 

How about the camshaft sensor on the front of the engine?
Have you checked for codes?

 

I bought a brand new RCM, I installed a new Bosch Crankshaft and Camshaft sensors and my car will not start. It attempts to crank but it doesn't start, there's no codes, also changed fuel pump

 

You have not stated the condition of the battery. Also, did you change the gas filter or just the pump? And have you checked the fuses to see if any are bad?

 

Yes I even went to autozone to check the battery and battery was perfect, I changed everything fuel pump and filter, I haven’t check any fuzes though any suggestions on which one?

 

Make sure the connector on the RCM is tight or that the wire isn't broken or loose.
The only fuse for the fuel pump is the one on the RCM as far as I know. See the picture below for details.

 

thanks but as I just said I bought a brand new rcm so its not the rcm

 

True, it might not be the RCM, but you should check if the connectors are on tight, the fuses are okay, or if the wires aren't frayed. Sometimes it's the simple things that get us. My car started running badly and it turned out to be one of the connectors on a fuel injector had come loose. Not sure how that happened, but I snapped it back in, and I was good to go.
-Jerry

 

I’ll check right now, but as i said before i bought a brand new rcm, BRAND NEW so it shouldn’t have any issues,

 

You may check the crankshaft position sensor to be sure its completely clean and seated. I replaced mine and the car would quit at 4000 rpm. I put the original one back in and plugged, unplugged and replugged it until I was positive it had a secure connection. It's still in there.

Les

 

Something I learned the hard way on several occasions is just because you bought a new part, it doesn't mean it's good. Brand new parts right out of the box can be bad. Just a suggestion.

 

I already tested the part and guess what It didn’t have any problem) thanks for all your help I’ll just keep looking till it turns on

 

I just spent $411 on a Mercedes refurbished part from Mercedes dealership that was bad for my wife's CLK500. Frustration isn't the half of IT.