CLK430 start cycle goes beyond 5 plus seconds
Thread Starter
Newbie
Joined: May 2020
Posts: 14
Likes: 0
08 Mercury Milan
CLK430 start cycle goes beyond 5 plus seconds
Hello everyone.
I've had quite the challenge with a 2001 CLK430 lately. We thought we had it solved when we replaced a faulty fuel filter with a faulty fuel regulating valve. Our issue is that when we start the vehicle, it takes 5+ seconds to start... whereas most vehicles will start almost instantly. As a matter of fact this vehicle has started in the past almost instantly and does so sometimes still. With the fuel filter, we thought that the fuel was being allowed to drain back to the tank because of the faulty valve in the filter; preventing sufficient fuel from being available at the engine on the start command. Before, we knew the valve in the filter was defective because our fuel pressure gauge wouldn't hold pressure when the ignition key was turned off, but did once we replaced the filter... we now have sufficient pressure at all times.
So, basically, I cannot understand why we are experiencing such a long duration for the engine to start. With the fuel pressure present on the pressure gauge, it seems likely that our problem may lie within the ignition system and not the fuel system. Any possible ideas from you guys on why the ignition system might be imposing a slight delay on allowing the engine to start?
Thanks.
I've had quite the challenge with a 2001 CLK430 lately. We thought we had it solved when we replaced a faulty fuel filter with a faulty fuel regulating valve. Our issue is that when we start the vehicle, it takes 5+ seconds to start... whereas most vehicles will start almost instantly. As a matter of fact this vehicle has started in the past almost instantly and does so sometimes still. With the fuel filter, we thought that the fuel was being allowed to drain back to the tank because of the faulty valve in the filter; preventing sufficient fuel from being available at the engine on the start command. Before, we knew the valve in the filter was defective because our fuel pressure gauge wouldn't hold pressure when the ignition key was turned off, but did once we replaced the filter... we now have sufficient pressure at all times.
So, basically, I cannot understand why we are experiencing such a long duration for the engine to start. With the fuel pressure present on the pressure gauge, it seems likely that our problem may lie within the ignition system and not the fuel system. Any possible ideas from you guys on why the ignition system might be imposing a slight delay on allowing the engine to start?
Thanks.
MBWorld Fanatic!
Joined: Nov 2001
Posts: 1,258
Likes: 209
From: Boston North Shore
2001 CLK320 Cabrio
Was glad that installing another fuel filter corrected the former, really long starting time issue (after the vehicle was parked).
Because the pressure regulator is built into the filter, substandard filtering material etc., there have been quite a few problems when the replacement was a knock off part (Uro, Purolator etc.) vs. a non genuine MB or it's OEM supplier.
I always purchase parts from one of the forums on-line suppliers, who offer both genuine MB and/or OEM at comparable prices.
Example: https://www.fcpeuro.com/Mercedes~Ben...5&b=9&d=208&v=
At this time, have you checked yourfuel delivery vs. the MB test specifications?
The fuel pump should deliver 1 liter of measured fuel in 35 seconds.
The fuel pressure with the engine at idle should be between 3.7 bar (55.66 psi) and 4.2 bar (60.92 psi).
The fuel pressure leakage numbers should be greater than 3.0 bar (43.5 psi) after engine shutoff and greater than 2.5 bar (36.3 psi) after 30 minutes.
Because the pressure regulator is built into the filter, substandard filtering material etc., there have been quite a few problems when the replacement was a knock off part (Uro, Purolator etc.) vs. a non genuine MB or it's OEM supplier.
I always purchase parts from one of the forums on-line suppliers, who offer both genuine MB and/or OEM at comparable prices.
Example: https://www.fcpeuro.com/Mercedes~Ben...5&b=9&d=208&v=
At this time, have you checked yourfuel delivery vs. the MB test specifications?
The fuel pump should deliver 1 liter of measured fuel in 35 seconds.
The fuel pressure with the engine at idle should be between 3.7 bar (55.66 psi) and 4.2 bar (60.92 psi).
The fuel pressure leakage numbers should be greater than 3.0 bar (43.5 psi) after engine shutoff and greater than 2.5 bar (36.3 psi) after 30 minutes.
Thread Starter
Newbie
Joined: May 2020
Posts: 14
Likes: 0
08 Mercury Milan
Thread Starter
Newbie
Joined: May 2020
Posts: 14
Likes: 0
08 Mercury Milan
Was glad that installing another fuel filter corrected the former, really long starting time issue (after the vehicle was parked).
Because the pressure regulator is built into the filter, substandard filtering material etc., there have been quite a few problems when the replacement was a knock off part (Uro, Purolator etc.) vs. a non genuine MB or it's OEM supplier.
I always purchase parts from one of the forums on-line suppliers, who offer both genuine MB and/or OEM at comparable prices.
Example: https://www.fcpeuro.com/Mercedes~Ben...5&b=9&d=208&v=
At this time, have you checked yourfuel delivery vs. the MB test specifications?
The fuel pump should deliver 1 liter of measured fuel in 35 seconds.
The fuel pressure with the engine at idle should be between 3.7 bar (55.66 psi) and 4.2 bar (60.92 psi).
The fuel pressure leakage numbers should be greater than 3.0 bar (43.5 psi) after engine shutoff and greater than 2.5 bar (36.3 psi) after 30 minutes.
Because the pressure regulator is built into the filter, substandard filtering material etc., there have been quite a few problems when the replacement was a knock off part (Uro, Purolator etc.) vs. a non genuine MB or it's OEM supplier.
I always purchase parts from one of the forums on-line suppliers, who offer both genuine MB and/or OEM at comparable prices.
Example: https://www.fcpeuro.com/Mercedes~Ben...5&b=9&d=208&v=
At this time, have you checked yourfuel delivery vs. the MB test specifications?
The fuel pump should deliver 1 liter of measured fuel in 35 seconds.
The fuel pressure with the engine at idle should be between 3.7 bar (55.66 psi) and 4.2 bar (60.92 psi).
The fuel pressure leakage numbers should be greater than 3.0 bar (43.5 psi) after engine shutoff and greater than 2.5 bar (36.3 psi) after 30 minutes.
The good news is that the customer has recently reported that the time between initial start sequence and actual engine starting has improved drastically... almost to a normal state. He and I believe that there may have been some hint of air in the system that created some issues on the prolonged start sequence after I replaced the filter and it just took a few start cycles and some drive time to work out the air... who knows, haha.
Regardless, thanks for all your help and suggestions as it appears we might be back to where the customer is once again a happy one.
Best!!
MBWorld Fanatic!
Joined: Aug 2006
Posts: 7,053
Likes: 398
From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
Usually this delay starting caused by:-
weak fuel pump armature, or some of injectors valves went bad, or bad Engine harness..!,,
did you check any of these..??
-;-ZAYED-;-
weak fuel pump armature, or some of injectors valves went bad, or bad Engine harness..!,,
did you check any of these..??
-;-ZAYED-;-
