2000 ml-430. 113,000 mostly trouble-free miles.

replaced fuel pump and filter at abt 50,000 miles. shows 50 psi on the
fuel rail at engine.

replaced CPS. still, no start. tach hangs around 200 rpm while cranking.

get short blink from red LED above fog lite switch, so DAS is ok (?)
tried 2 keys and valet key, no start.

timing light on a plug wire shows i am getting fire during cranking sequence.

whats next? compression test or pull valve cover to see if timing chain
has let go??

dead in the water

dan, longview texas

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dan

The three things that i've seen replaced alot on ML's is the passenger seat recongnition sensor, CPS, and the Ignition switch. Did you check all your fuses to see if any of them are burnt?

yes, i have checked EVERY fuse under the hood and in cabin on pass. side.
all ok.

ignition switch? how do i troubleshoot that? it does crank and i do have
voltage on spark plug wire.

so, try again with my wife in pass. seat?

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dan

I have nothing useful to offer this thread, but I am curious as to how the passenger seat sensor could cause a no-start. I'm just wondering what little "feature" would explain that.

Curious, that's all.....

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-tp


1990 300SE "Corinne"- 145k daily driver - street modified differential - PARTING OUT OR SELLING SOON - PORTLAND OR. AREA - PM ME FOR DETAILS
1988 560SEL "Gunther"- 190K passes anything except a gas station
1997 S420 - 265k just bought it with a rebuilt trans. Lovely condition

When the key is, there should be power to the coils & to the injectors. The computer creates the ground to fire them.

Is there power to the coils with the key on?

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
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190E 2.3 16V ITS SCCA race car (sold)
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Retired Moderator

Also - you need to buy a "NOID" light to check for fuel injector pulse. make sure the gas is getting squirted into the engine.

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Do it right or dont do it at all!

I pulled #1 A plug. it looked perfect. put compression tester in. ran cranking
cycle (again, no start) 180 psi.

so, i have compression, gas and fire. (didnt use a noid light yet). figured
its got to be the gas.

drained the tank dry, using a piece of #14 stranded between + batt term
and right side of fuel pump fuse socket, with fuel pump relay and fuse removed.
I use ac gauges to measure fuel pressure and it was easy to open the
valves and dump fuel in 5 gall gas cans. dumped the bad gas, for now,
into my 100 gal boat gas tank.

went across the street, to a different gas station, put 5 gall of fresh gas
in her.

IT STARTED! ran very rough, but started. put the big bottle of chevron
fuel system cleaner in tank, after re-draining, then poured 10 gal. of fresh
gas on top to mix. ran a little better, good enough to get to work. let it
sit overnight.

check wallet light comes on with various cryptic cylinder misfire codes.
just like the ones i see when MAF fails. switched out the MAF with a spare.
she coughed and sputtered a bit on my commute, then suddenly,
smooth as silk. topped her off with fresh tank of premium. clearing
MILs with code scanner, will see whats next..I doubt the original MAF is
bad....only about 50k miles on it.

thanks all for advice. its a long ways to the nearest dealer.

NOID lights.......hmmm....prob. should replace fuel filter, but have good
solid 50 psi on the fuel rail..

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dan