This 'cranking' session is only about half as long as some of the worst, but you get the idea and should realize it is excessive.

See it at the link below

http://www.youtube.com/watch?v=AXv61x3gz7s


SQ

 

Crankshaft Position Sensor.

 

Any supporting evidence?

 

Mine never does that. It always cranks right up. If its been sitting for 3 or 4 days in freezing temps its a lil rough at initial idle, but thats to be expected. I guess I'm just lucky.

 

Check the mercedes boards if you don't believe me.

Here's an easy test:

1. Use AC Multitester
2. Disconnect CPS
3. measure AC voltage across cps while cranking.
4. if you have voltage, then the CPS is fine. If you don't have voltage, then your CPS is broken.

Have you noticed that the problem is getting worse over time?

 

The problem hasn't really become worse over time - it is really inconsistent, but if I had to show someone I would drive the car hard and then let it sit for 30mins, then go and crank it.

Can the CPS be intermittently 'broken'? In other words, if I remove it and measure voltage while cranking, will it read good sometimes and bad the other?

I did check the MB boards - and most of them seem to think it is a fuel issue.

For the record, the car has never stalled, or tried to stall at a stoplight like a lot of the CPS problems I read about. It did have one episode where my wife let it idle for 15mins in the AM while she finished getting ready for work. She went out to the car and the car was running rough with a check engine light. She tried to pull it out of the garage and it was running so bad she pulled it back in and took another car. I got home to check it out and all was well.

SQ

 

check here , Mine does this if i tap the key ..
but if i manually start it does not ...

https://www.crossfireforum.org/forum...light=cranking

FOUND THIS

automatic power ignition - 08-17-2004 , 09:48 PM

-----------------------------------------------


hi guys&gals, anyway,the new topic is about the ignition switch in our car, its smarter than you know! if you would like to prolong the life of your ignition, next time when you start your car, just turn the key to crank the car , than let it go immediately, the ignition will continue to crank until the car starts , all by its self !!! its the coolest thing! try it for yourself. well,bye for now , and take care of your investment, its a lot of car for the money!!!!!!

 

I'm familiar with this feature and this definitely isn't what I'm referring to.

 

Yes, it can be intermittently broken. Testing is the surest way. Anyways, your videos showed cranking taking 3.5-4 seconds, not 7-10 as you say. It's not that I don't believe you, but I counted the time on the video.

Fuel problems - ok, fuel problems are something else. When you start the car and put the key in the ignition, the fuel pump starts up. You should immediately have fuel for the engine when you crank. Fuel pumps rarely break intermitterntly. Same with Fuel Filters. With an SRT6, with its high gasoline needs, your car would be dying all the time if either of those units were at fault. When you turn the key to position 1, you should hear a "whirring" noise. That is a combination of a few things making noise but one is your fuel pump. It is shooting fuel through your fuel system and that is on an open loop through the injector fuel rails back to the fuel tank. You should be getting fuel.

OK, assuming that your ECU isn't broken then either your car isn't getting spark or it's not getting air. You don't have VALVETRONIC or anything on this car it is a good old fashioned throttle body, so you're getting air. Which means that your engine isn't sparking. If your engine isn't sparking, then we have to think about your coil packs, wires or plugs. Since this car is coil on plug, probably not wires and probably not coils. So the other thing that the engine uses to start spark is to read the timing on the car by use of the Crankshaft Position Sensor.

CEL - OK, you didn't mention this before and this is good. This means that your engine threw a code and now you must get the code read. Go to autozone, pep boys or checkers and ask for a code-reading tool. They will give you one for free to use. BTW, a good OBD2 scanner should be able to show you fuel rail pressure so take note if you can!!! My bet is on ECU Code "O2 Sensor reading low/high" something to that effect.

 

I agree - as stated, the current video is not the best (or worst, depending which you prefer). However, it is obviously having trouble firing and shouldn't take 4 seconds to do so. There have been a dozen or more times when the car will crank all the way through it's cycle (which I believe is 8-10secs) - at this point, the car realizes it is not going to start and then shuts off the starter. Try it again, and it fires right up - everytime this has happened, no problems starting on the 2nd try. I haven't been able to catch this on video yet, but I'll keep trying.

I always hear the CPS issues cause a car that wont start at all, and wont stay running. They also say the car stalls. This has never happened, however it could be on the horizon I suppose.

The fuel pump definitely initiates when the key is in the 'on' position - no problem there. However, there is a check valve that holds pressure in the lines when the car is turned off. This supposedly prevents the fuel from returning to the tank when you shut the car off, and allows quick fuel when you hop in to start the car. This is prone to leaking on the SLK32's from what I've read, which causes hard starts.

Here is a section I found in the SRT-6 Service Manual, Page 14-4:
"DIAGNOSIS AND TESTING - FUEL PRESSURE LEAK DOWN TEST
Use this test in conjunction with the Fuel Pump Pressure Test and the Fuel Pump Capacity Test.

CHECK VALVE OPERATION
The electric fuel pump outlet contains a one-way check valve to prevent fuel flow back into the tank, and to maintain fuel supply line pressure (engine warm) when the pump is not operational. It also is used to keep the fuel supply line full of gasoline when the pump is not operational. After 30 minutes the fuel pressure may drop to 2.5 bar (36psi), but the liquid gasoline will remain in the fuel supply line between the check valve and fuel injectors. When the fuel pump is activated, the fuel pressure should immediately (1-2 seconds) rise to specification.

Abnormally long periods of cranking to restart a hot engine that has been shut down for a short period of time may be caused by either fuel pressure bleeding past a fuel injector(s), or fuel pressure bleeding past the check valve in the fuel pump. "

It continues on with how to fix it....

Seems to make sense...

Upon getting home after my wife told me about the CEL, I undid the battery - did this dump the codes or just clear the light? If it dumped the codes, then I am SOL.

Thanks for the info.

SQ

 

have you tried turning the key on the on position for 10-15 seconds just to make sure that the pump is priming the fuel lines fully....and then cranking the engine up?

 

Yes, I have...and it will still crank excessively at times.

However, should I have to do this? There are no glow plugs or heater grids like I've got on my diesel. I should be able to insert the key, crank, and start...shouldn't I?

 

Your right you shouldnt have to do this, i was just trying to rule out the possibility of lack of fuel. Since its not a return style system it doesnt sound like fuel is leaking straight back into the tank.

 

Shawn,

CEL codes should be stored in NVRAM (Non-Volatile RAM) and are still readable.

I'm putting my money on O2 sensor reading rich caused by missing spark on stumbling.

 

I had this when I first bought my car. It was the fuel pump. I did post the repair invoice. Don't remember the title of the thread. Took the dealership like 2-3 days total. Was diagnosed right away. Was lucky enough to long crank right in front of the service advisor. Mine would always crank long first, then start on the next one. I believe they told me there were 2 pumps and was the one outside of the tank.
Good luck,
Cruzinquick

 

Cruzin,

I was the one who asked you for that invoice and I took it with me to my dealer who 'could not duplicate the problem'.

I know now that 'could not duplicate' stands for 'could not solve', so I'll be going to another dealer.

SQ

 

That was a while back. You deserve the Most patient SRT owner award. I wasn't happy with my dealership at first, but they always seemed to fix the problems. It's definately time to find a new dealership. It sure sounds like the fuel pump problems I had. Wish I could help out more.
Cruzinquick

 

I'm a little patient...but when you go to the dealer and they ask if you had your seats custom embroidered (they saw the SRT logo), You learn really quickly not to expect too much out of them !

I found a dealer within 20 miles that has an SRT certified mechanic who has done a decent amount of work on the SRT-6. I'm hoping to take it to him mid next week, with your invoice and my video. I just thought I'd ask to see if anyone else has had it happen yet, and if there were any other ideas for a cure.

Thanks for the help.
SQ

 

BTW, this car has one fuel pump, not two.

 

That should be on a shirt. LOL, 100 octane gas is needed to get away from this dealership in a hurry.
Cruzinquick