D. I. G. means Dead In Garage. I drove it in there a few days ago. It sat quietly for 4 or 5 days. I go to start it the next time, the engine spins happily for 6 or 7 seconds, but without a hint of trying to fire. No sputter or any attempt to fire, it just cranks for that length of time then stops cranking. I can repeat the process, and it cranks some more, but no hint of start. I searched through this forum and found 2 different common causes for no start on Crossfire... the CPS Crankshaft Position Sensor and the RCM Relay Control module. (Thanks to all the givers of their knowledge here on this forum!)

This is an '05 SRT6 Coupe purchased new, now has 11,000 miles on the odo, the battery is about 6 months old and very strong. This car is gloriously unmodified, bone stock. I have had zero problems with it for 6 years, until just now.

I bought and installed a new CPS as outlined here, still no start. I removed and re-soldered the RCM pins that cause some cars not to start, still no start.

So does anyone know what else I might try to flush out this problem? I've got a Service Manual CD, tools, and above average wrenching skills, but most of what's under my hood is still a mystery to me.

I'd appreciate any suggestions that any of you folks have to offer. Thank you.

 

Sounds like the CPS Crankshaft Position Sensor. There have been folks that bought new ones only to find they are bad.
Do you still have the old CPS? Test it with a multimeter to see if you have continunity through it.

Did you check for fault codes?

 

I would find a way to see if the camshaft sensor is good. Using a scanner, see if you have any codes. Also try to read if you are getting any rpm while cranking the engine.

Fuel. Do you hear the fuel pump working momentarily with the key on without starting the engine? The pump should run 2-5 seconds when the key is turned to 'on'. If so, you need to check for fuel pressure.

James

 

You've already repaired/replaced the obvious, James has mentioned the Fuel Pump above. If none of these, sounds like the security system is preventing the start?? Have you tried your other spare key?

 

you say cranked 6 or 7 times and no start. As in dead battery no start. Like it runs down the battery or am I wrong here? I had an issue with this once, and it was the corroded connections on the battery terminals. They looked clean but weren't clean enough as it turned out. I also will assume you have disconnected the battery and reconnected it. Just sounds electrical to me. Check ground wires, especially to the starter...

 

No no.... when I turn the key the engine spins normally and strong.... for 6 or 7 SECONDS, then stops cranking. I can repeat this over and over.... the battery is very strong. The engine just refuses to fire... like not one pop of one cylinder at all.... just cranks for 6 or 7 seconds then times out.

In discovering this problem, I now realize that Mercedes Benz engineering logic let's you crank the engine for those few seconds, but then they have an automatic timeout for starter motor engagement, until you wind the key backwards and start it again. I had never run into this timeout before, as the car ALWAYS started within a second of cranking starter engagement.

 

I'm not a big fan of ether, but that would let you know if it's fuel related. Not advising to do it either, but someone with more experience there might have some input. Have you noticed you don't have to hold the key in the start position? It's almost like turning the key activates a timed relay. The valve on the fuel rail should let you know if you are getting fuel pressure. If you have pressure I'd have to give a +1 to the bad CPS thoughts.

 

OK, I misunderstood. I am in the CPS mode now. There are new ones out there that just don't work. I bought my last one at Auto Zone. It has been fine for sometime now. Although it usually would start acting up and give you some warning. Sound like this isn't the case with you. So many sensors on these car. Throttle sensor, security system.....just have to start weeding them out....

 

Yes I have the old one still, I will check it tomorrow.

Fault codes..... hmmmmm... that's the next thing I need a tutorial on. I don't know what I need to read this car's fault codes. I know on some older cars, the digital radio dial acted as a code display screen, but I think you're probably talking about the scanner gizmo that plugs into the (OMB???) socket under the dash somewhere. Where do I get a scanner?

 

Check engine light on? If not it hasn't sent any codes.. and yes the OBD II scanner.. can get on Amazon for about a $20 dollar bill.

 

I've probably scored a lot of cylinder walls in reluctant old engines over the years using ether.... I'm not a fan of it either.... at least for this car....

Yes, I did notice that the key strikes the "start" position and can then be released, doing as you suggest probably activating a timed relay, that cranks the engine until it fires, or until 6-7 seconds passes, whichever occurs first. I'll check the audible on the fuel pump tomorrow.

A bad CPS out of a sealed bag, made by Bosch, would be a bummer.

 

If I recall all the bad components mentioned have been camshaft sensors, A Bosch part should be golden.
I am all for the fuel not being present, if so then the pump will be the culprit. If you hear the pump it should be good, if not that will be the problem. I assume you have not let the tank run out of gas.
You should smell gas if it is an electrical fault.

 

Spray starting fluid in the throttle body to eliminate the fuel system as a problem.
If it doesn't start and run while you spray then it's most likely not fuel related. (Be careful!)

 

I believe the auto run activated starter is due to the 'pulse module' used in the circuit. It allows the starter to crank for a specific time OR until the engine starts.

DJ - One thing to remember about starting fluid. If there is ABSOLUTELY no fuel sitting in the engine, starting fluid will not allow it to run. Yes most of the time there is enough fuel to allow the starting fluid to work, but not always. Been there done that many times.

 

This is exactly the same thing that happened to me when my CPS failed.

Most of them will give you a warning, mine did not. Parked the car at Steve's house one day to grab a car part, got back in, and it was dead. Would "crank" all day long but never fire. We replaced the camshaft sensor front of the motor, behind the belt) and that was a waste of time. Put the OE cam sensor back in, and swapped the crankshaft sensor (back of the motor) with a Bosch unit. Fired up immediately. No problems since.

$45 and my issue was fixed.

 

On listening for the fuel pump : if you are my age ( or 180's age ) then maybe you should lie down with your head at the front of the passenger side rear wheel and have someone else switch on the key ( this is where the fuel pump is located ).

 

Clogged fuel filter/pressure regulator ???? Just a thought !!!!

 

Thanks to everybody for your suggestions and comments so far. My next move is to get an OBD II scanner and see if any error codes are issuing. I do hear the fuel pump turn on when I turn the key to position one.
As far as Check Engine light.... I get no individual lights (OK, one light, the seatbelt light) when I turn key to position one. When I turn to start position, 14 dashboard lights come on and stay on until I turn the key back to off. So, no specific Check Engine light.
I have less confidence that it is a fuel delivery problem, than an electrical ignition problem. If the fuel system, the fuel pump, the fuel filter, regulator, were failing, I would think that I would get at least a sputter, even one pop, when I first tried to start it. But when it quit, it quit cold turkey. Not even the slightest effort of lighting a mixture.
I think something is shutting down the computer, and that is withholding both spark and/or fuel injector signal. Something like the CPS sensor..... but I replaced the original CPS with a new Bosch unit.... still no start. I have to find out what other sensors have the same effect on the computer.

"Pulse Module"..... got it, thanks for the clarification.

I'll keep posting back here until I get this problem solved. Thanks all.

 

"Sounds like the CPS Crankshaft Position Sensor. There have been folks that bought new ones only to find they are bad.
Do you still have the old CPS? Test it with a multimeter to see if you have continunity through it."

Since you are now experienced with pulling the cps.. I'd be real tempted to pull your new one (installed) and check it. Just a thought.