ML320CDI crank but no start - PeachParts Mercedes-Benz Forum

smacmoyle · #1 01-31-2011, 09:18 PM

This is the craziest thing. When the vehicle is stopped and a restart is attempted while the engine is warm it will crank but not fire. wait 5 minutes still not start. wait 30 minutes and it fires right up and drives like nothing ever happened. this has happened twice now. the exact same thing. no start until I wait 30 minutes. I guess I should change the fuel filter. (thats diesel 101 for winter operations) but I dont think that fits the problem. I have read about crankshaft position sensors being a problem. that sounds resonable. please help. Its winter here in NJ and getting worse. I need this vehicle badly.

Thanks,
Scott

nhdoc · #2 01-31-2011, 09:33 PM

CPS is known to fail under those conditions (when heat soaked) so it is a possibility. Has the car thrown a check engine light? You might still check it for stored (pending) codes with an OBDII scanner.

smacmoyle · #3 01-31-2011, 09:43 PM

No codes, I need to buy a new code reader to check pending codes. It sounds like a prime suspect to me right now. looks like I will be spending more time with Mr. Google tonight. Thanks for the fast reply.

Otherwise, this is the most awesome vehicle I ever owned. It gets 27 MPG all the time. Even more if I baby it. lots of power too.

smacmoyle · #4 01-31-2011, 10:30 PM

Can anyone tell me how hard it is to change a CPS on this engine ? the EPC pic doesnt really help much. I found one on the web. I will see if I can get one locally tomorrow.

smacmoyle · #5 02-01-2011, 11:35 AM

I found it. Its under the exhaust manifold. Left side. It doesnt look hard to do. I still have warranty left. the recall has been done already. I wonder if it would be covered under warranty. It would cost me $125 diagnosis fee if warranty was rejected.

smacmoyle · #6 02-01-2011, 03:47 PM

Never mind, I figured it out. Its under the LH exhaust manifold. Guess why it fails when hot.... ( that was sarcasm) anyhow. $40 and 2 screws and one plug. Not bad....

vstech · #7 02-01-2011, 06:25 PM

I just noticed on a 95E320 I was working on, that MB put not only a heat shield, but also a cold air duct on the MOTOR MOUNT under the exhaust manifold... is there anything like this on the CDI?

Jeremy5848 · #8 02-01-2011, 06:33 PM

Quote:

Originally Posted by vstech

I just noticed on a 95E320 I was working on, that MB put not only a heat shield, but also a cold air duct on the MOTOR MOUNT under the exhaust manifold... is there anything like this on the CDI?

Our '96 E300D also has an air duct to the right motor mount.

smacmoyle · #9 02-01-2011, 07:56 PM

its got a shield but no air duct. an air duct sounds like a good idea.

smacmoyle · #10 02-02-2011, 10:30 PM

she failed again tonight... Same thing... started fine after a 45 minute cool down. This time after I got home I waited 15 minutes, attempted a restart, it failed to start, I shot a little starter fluid in the intake and it fired and quit, I poured cold water on a rag, put the rag on the pump, cooled it down and got it to start. So I guess it could be the pump. There is also a fuel temp sensor and some other sensor or something with a connector on it. I will try disconnecting the fuel temp sesor tommorow and see what happens. I ordered a fuel filter today. I dont think it will help but I have to rule it out. I could really use some help here. There is got to be someone out there that knows this engine.