Sulaco

Car randomly decides not to start. Sometimes I turn the key and the starter doesn't even engage. Roll the key back and try again and it might start right up. Other times it fires right up but immediately dies. Try again and it might immediately die again. Ultimately it always starts and goes fine, but roughly 1 in 4 starts gives me this trouble. Installed new CPS last week and problem is still here. Whiskey Tango Foxtrot?

cm60k

Is that a genuine CPC..?, any codes appears after CPS installed..??

ZAYED,,

Sulaco

No codes before or after. It's a duralast cps...

cm60k

Is it the same Bosch quality..?,

BTW; if no codes, that will be soo strange.!,

check deeply for the CPS or starter or alternator wires or connectors, if they loose or wires connected to each others...?!?

ZAYED,,

Ausmbtech

I don't think you have a CPS issue, sounds like you might have an immobiliser issue. Have you tried starting it with another key?

Sulaco

It's a brand new key straight from MB and it's the only key I have.

RPB

Sounds like something is not communicating properly.

Sulaco

What could I do to test?

DRBC43AMG

Try a hammer

Just joking, but to me it also sounds something related to the key and sender

mickey13

Did someone say hit it with a hammer?

fredtga

If the CPS is bad, the engine would still crank but will not start.

If you turn the key in the ignition and nothing happens, won't even crank, then for some reason the key is not recognized by the system. I had this happen in many cars of mine and 99% of the time was the key. Over time, the key just "dies".
If you have another key, try with that one.
Since you're saying that in the end after many tries, the car starts, it means that every other component works fine.

If your CPS is new, you have no codes, and car immediately dies after it starts, i would start looking at the fueling system... FPR or fuel pump.

Sulaco

Thanks Fred. It's a brand new key. I can't afford yet another $230 key for testing. I'll see what I can do otherwise. And it's never more than 2 or 3 tries before it starts fine. It's not really a problem yet, I was being proactive.

It does 2 things at random: key doesn't engage starter (but activates all other electronics) or car starts then immediately dies. Sometimes it does both back to back.

For your enjoyment, 2 idling C43s. C43 idling in stereo:

Pagz

Sulaco,
EXACT same thing happened to me with my new key. I havent bothered to chase it any further I just use the older spare key and new key as backup - runs fine most of the time but it just has a random non start or start and die straight away issue.

cm60k

+1 with paul,

Key infrared signal could cause that miss ECU signal through "E. Starter Switch",

when dealer program new Key, they put the same infrared signal that saved in old Key, starter switch not reads the current signal during to the updated software in new Key program,,

IMO; MB should to replace both of them together, not only the Key...!!

ZAYED,,

Saaboteur

Are the battery leads on nice and tight, and no corrosion around them? Sounds stupid, but my motto is always to check the stupid stuff first.

If memory serves, there's also a cam position sensor, so perhaps you can check that, but these things are simple, just magnets really.

nkctb7

Hey Sulaco,

Did you notice any oily fluid on the bottom of the cps when you removed it? I was having the very same problem. Upon removing the old cps, I noticed an oily fluid on the bottom of the cps. When the outside temp. dropped to around freezing, my car would not start. I took a chopstick and put a cloth over the end and pushed it in the cps cavity to give it a good wipe. This corrected the cps issues. I'm not saying that this will work for you but, it may be worth a try.

Sulaco

Cps was dry. Perhaps my new key is bad? What's the warranty on a new one? I've had it maybe 6 months.

DRBC43AMG

I like the birds singing in the background...

DRBC43AMG

Chopsticks in the toolbox? That's a new one to me and never thought it could come in handy one day

Sulaco

Haha, and the chain rattle on my silver beast.

Thinking about removing resonator or something on it and letting the wife's car be the quiet one. Can't afford a damn thing right now though. Don't I need to have a X pipe or something custom fit?

DRBC43AMG

Yes, remove the secondary cats and resonator, then fit a ss tube in place. Saves weight too when you see what the cats and resonator weight ;-)

FrenchBenz

As DBR said, it's a pretty cheap mod and saves a lot of weight. I don't think you need an X-pipe, I just replaced the secondaries and resonator with a Y pipe and it works and sounds great. There might be a slight drowning but barely noticeable... It does free up the car at the top of the rev range though