Mercedes-Benz Forum banner

stall after car park for few days and in the morning

1K views 14 replies 8 participants last post by  johnma 
#1 · (Edited)
Ml500 is experience an issue in the morning after parked for a day or 2+. When I startup the car in the morning, it will stall right away. What I did was to turn the key to ON position for few seconds, follow by startup the car, it will startup and good to go. Don't have any issue afterward for the next time vehicle seats for a day or 2.

No code found by scanning. No warning lights.

I am trying to tracking down the issue and fix it before a bigger problem..

Possible fuel pump? or some how fuel pressure was lost over a day or 2.

Thanks.
 
#2 ·
Do have a fuel pressure gauge or access to one?

If so screw it on to the fitting at the end of the rail after it has been sitting
and it should show about 31-33psi. If it does not then it is a fuel feed issue
that in many cases is pretty easy to resolve. More than half the time the
fuel pressure regulator built into end of the filter gives up and the pressure
is lost there.
 
#4 ·
I'm back on this thread again. Fuel filter was replaced during spring time. Everything works fine until those few cold days where I had to crank the truck 3 times to get it started. Drive fine after started. This appears to happen only during days below 32 degrees.

Fuel pressure tested using gauge. engine running ~55, engine off ~50. after 4 hours, pressure went down to 0. However, I was able to start even at 0 pressure. This might be problem for freezing temperature days.

Is there a check valve in the fuel pump to hold the pressure after shutdown?. or it's all in the fuel filter.?

JM.
 
#12 ·
I did the test over the weekend. Here are the results of pressure lost.

55psi engine running
50psi engine off - 0 min
48psi - 40 mins
23psi - 70 mins
~0psi - 4 hours

Weather was in the 40s during the time. I was able to startup without any issues.
 
#11 ·
Check fuel pressure using gauge set designed for CIS injection. Put gauge inline with feed hose to injector rail. CIS gauge set has valves before and after the gauge. By closing valve you can quickly determine which side is causing pressure loss.

Loss of pressure to 0 overnight on feed side is not a problem as long as it recovers with one key off/on cycle.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top