GL350 Cranks but won't start when hot (sometimes)
Has been doing this for 20K miles, and progressively getting worse. (up to twice a week now) If you sit for a few minutes it will crank for a while then start.
I've monitored live fuel pressure once when it wouldn't start and saw rail pressure just a hair below 14K PSI. Then at that time it started and pressure was fine. Over this time period, I've ruled out poor fuel. Electric fuel pump is humming even when it won't start.
NO ERROR CODES! Driving me crazy!!
If it would stay in a failed state, it would be much easier to diagnose. And it almost aLwAyS happens when the wife is in it, except a couple times, so I have only gotten the C4 on it in time
once.... 
This thing runs amazing once started. Cold or hot weather doesn't make much difference.
Any insight fellas?
TIA
Clint
maybe change that if they are cheap?
and isnt there something about a differential pressure sensor that causes issues, not sure if they were no start issues
and what about eis? have seen that mentioned some
please let us know what the solution is when you figure it out
does not sound like a fun problem




Here is what the tech wrote:
"Replaced RELAY 002-542-26-19 $41.25.
71467 The car would start when hot after heat soak for 30 seconds. SDS TEST. No comm with CDI control module during no start. Found 87 Circuit relay F58kd not powering up CDI when hot."
The tech opened the relay and showed me that one of the internal contacts seemed burnt with no sign of being soldered.
I hope these helps.
Trending Topics
Noticed that rail pressure is just barely below 120BAR so I did the pressure regulator test, and it failed by letting too much fuel quantity bypass during crank. >2Tbsp. I had about a cup.
Whilst waiting on the new Bosch replacement, now I have a knock noise. It sounds serious. I'm really regretting the purchase of this vehicle.
The Best of Mercedes & AMG
but the differential pressure sensor screws up starting i think, not sure if it throws a code or not
seems the cold kills the dps if it is weak
it is a cheap part i think
have no idea on the knocking
good luck
I could write a lot on the subject, but feel free to read here:
https://sprinter-source.com/forum/sh...ad.php?t=27630
Those would be my next steps.
The knocking- get a mechanics stethoscope and listen carefully- does it come from the high pressure fuel pump on the front of the engine? That might be another reason why you experience hard starts sometimes.
I could write a lot on the subject, but feel free to read here:
https://sprinter-source.com/forum/sh...ad.php?t=27630
Those would be my next steps.
The knocking- get a mechanics stethoscope and listen carefully- does it come from the high pressure fuel pump on the front of the engine? That might be another reason why you experience hard starts sometimes.
Stethoscope sounds like its coming from the piston top, or cam. I disconnected the serpentine belt with no change.
Here's the video link to it
Keep in mind, this will go away for a few minutes, then the noise returns.
I'm very new in this forum. Anyway, i have GL320 2008 model Diesel which cranks but won't start when the engine is hot. I tried changing CPS but didn't help.
Now a different mechanic is telling me i need to replace 4 injectors. But i would like to be sure if there is a possibility that a bad injector(s) can cause this problem of engine cranks without starting when hot.
Thank you in advance for any insight that you may provide.
Thanks,



