m117 cold start issue (560SEL) - PeachParts Mercedes-Benz Forum

JamesDean · #1 10-18-2010, 09:38 AM

Hello everyone,

A friend of mine has a 560SEL MY90 and is having trouble starting it in the cold. He told me that it took a good few minutes of cranking for the engine to start up and once it did, he had no power until the engine was a bit warmed up..

Anyone have any thoughts on this? Tune up is recent too.

pawoSD · #2 10-18-2010, 10:11 AM

Could be an issue with the idle air control, or the temp sensors on the engine. My 300 did the same thing when I got it, wouldn't start well, no power until warm...etc. I changed all the sensors and idle air valve and hoses, and it was much much better.

david s poole · #3 10-18-2010, 10:15 AM

check the fuse[s] on the ovp relay.the description you gave is perfect for limp home on that car.

JamesDean · #4 10-18-2010, 10:32 AM

if the ovp fuse was out wouldnt other idiot lights on the dash be on as well? ABS, etc?

pawo, the idle air stuff has all been replaced.

Temp sensors and the like, I'm not sure about.
The only thing I know is that the O2 sensor is disconnected, however that shouldn't effect start up, I don't believe.

He's also complaining about no heat, he flushed out the coolant system last week and replaced the main radiator hoses.
I suspect it just needs to be burped, it had heat prior to the flush/change.

And the final thing he's after is (1) accumulator and (1) hydraulic ram.

david s poole · #5 10-18-2010, 02:08 PM

not necessarily if double fuse version.

JamesDean · #6 10-19-2010, 09:55 PM

i checked fuses, and they were OK.

I just thought of this today, it might be OVP related actually. Does anyone know if cold start injector is (indirectly) connected to ovp?

Also, I just remembered the ABS idiot light is missing (wires hanging behind cluster, no fixture)

So, more investigation is needed.

JamesDean · #7 12-28-2010, 12:25 PM

Alright everyone,

So We managed to fix a high idle problem on the car however, we've still got some odd behavior under and around 60C.

Starting the car cold is hard. When it starts up it runs pretty rough. If you dont keep your foot down (rpms up) the engine will stall out. We checked the cold start injector and its getting voltage during cranking.