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Good morning fellas!
I'm brand new here and I live in Houston, TX. I'm hoping I can get little help/advice on my current "randomly wont start" issue from someone more experienced than myself on these cars.
I just recently purchased a 2003 E55 AMG (first Mercedes I've owned but I've always liked the E55's). I needed an affordable daily driver/work car that would still be nice and enjoyable to drive so I figured the E55 would be a solid bang for the buck option. Shortly after I began looking, this one popped up local at a good price.
I've had the car for about a week now. It has a few mods, mileage was reasonable at 103k. It seems to have been pretty well cared for. Price was more than fair at $6k for a clean title/clean history E55. 😬
Mods:
-74mm clutchless upper
-AMG belt wrap kit
-Aftermarket front mounted H/E
-Split cooling
-BMW power steering reservoir for additional coolant capacity
-BCracing coilovers
-Resonator/muffler delete with X pipe welded in
-KMC 19" wheels
Anyway, car has been great all week until this morning when it just randomly wouldn't start. The car turns over like it wants to start but just wont fire up. In the short time I had to mess with it before work, it seems like the fuel pumps are failing to prime/power up.
Previous owner said he just replaced the radiator, fuel pump setup and installed the coilovers not long before I bought the car.
Any ideas as to what my issue may be? My first thought was... fuel pump fuse/relay. I only had about 20 mins to mess with it before work. From what I googled, fuel pump fuse and relay are in the fuse box in the trunk but when I looked, I had a small 7.5 amp fuse in #004 which was still good and the relay in spot #A (without testing it) appeared to look normal. My car being an 03 E55 AMG, I read somewhere that those 2 spots are correct for non-AMG cars and that my fuel pump fuses are in a different location.
Can anyone point me to where they would be on my 03?
I plan to mess with it tonight after work. I'm mechanically inclined and I work on my own vehicles 90% of the time unless its something big that i dont have the space or time to mess with. On this E55 though, i just dont know much about them. This will def be a learning experience. Lol
Passenger side trunk area under the trim for the relay.
If it passes, other possibility is the CPS, common failure but I can't remember if that causes a crank and no start or just a no start without turning over condition.
Passenger side trunk area under the trim for the relay.
If it passes, other possibility is the CPS, common failure but I can't remember if that causes a crank and no start or just a no start without turning over condition.
Good luck!
Ok. Thank you! I'll dig on that side tonight to find it. Also plan to pull the doors off over the fuel pumps to take a look at see if theres anything pinched or visibly wrong.
I've ready about the CPS but figured when I couldn't hear the fuel pumps, that was most likely the culprit... unless they're just really quiet or they dont come on until youre turning the car over in which case they'd be difficult to hear.
I think if the cps is bad the tach won’t move when cranking. I had one go bad but it was while the car was running.
Good tip. I cant remember if it moved or not. I'll check that when I get home. What I do remember is every light on the dash being illuminated while cranking. That's prob normal while it's trying to start and then they turn off once it fires up but I just didnt notice that before now. Even the lights on my air ride buttons were illuminated... even though they dont do anything anymore since the car is on coilovers.
CPS will give you code. If no code is the starter. It happened to me 3 weeks ago. Paid $580 to replace a new one.
Hmm. I have a OBD2 scanner I can plug it up to see if its throwing any codes but since it wouldnt start... idk what lights would stay on or turn off again once it's actually running. I'm not sure it's the starter. The car turns over nice a quick like the battery has good power and the starter is working like it should. It just goes through its 3-4 seconds of turning over like it wants to start and then stops.
It could be as simple as a bad relay. I had a intermittent no start issue that would happen at weird random times. Relay socket and wires looked perfect.
It could be as simple as a bad relay. I had a intermittent no start issue that would happen at weird random times. Relay socket and wires looked perfect.
Im thinking the fuel pump relay will most likely solve the problem unless I have a bad connection somewhere from them replacing the pump recently. The fact that the pump doesnt prime tell me the CPS is prob just fine and my issue is fuel related.
So... I ran around after work grabbing a few specialty tools and the fuel pump relay.
I came home to start working on it and before I started, I figured I'd try one more time to see if it would start and boom... it fired right up. No check engine light or anything. 100% like it never happened in the first place. 🙄
So now... I'm assuming since there no light... CPS is prob ok. I'm assuming I have failing relay. Any other ideas as to what could cause a ghost symptom like that? Lol
So... I ran around after work grabbing a few specialty tools and the fuel pump relay.
I came home to start working on it and before I started, I figured I'd try one more time to see if it would start and boom... it fired right up. No check engine light or anything. 100% like it never happened in the first place. 🙄
So now... I'm assuming since there no light... CPS is prob ok. I'm assuming I have failing relay. Any other ideas as to what could cause a ghost symptom like that? Lol
CPS won't throw an error code until it's so far gone your car is literally stalling when pulling up to a red light. Relays rarely intermittently fail. They stick, or the wiring is burned preventing conductivity.
CPS won't throw an error code until it's so far gone your car is literally stalling when pulling up to a red light. Relays rarely intermittently fail. They stick, or the wiring is burned preventing conductivity.
Well damn. I thought no CEL would be my green flag that the CPS is good. Nevermind. Lol
It did kind of stumble to a start though when it started the first time i tried but after it idled for about 30 seconds, I turned it off and then started it again. The second time was 100% quick like normal. I just assumed the stumble to life the first time was from either a shortage of fuel or being flooded on fuel from trying to start it several times this morning with no luck. It's normal now though.... for now.
I guess I will check wiring tonight and pick up a CPS to carry with me incase that's the issue.
Well damn. I thought no CEL would be my green flag that the CPS is good. Nevermind. Lol
It did kind of stumble to a start though when it started the first time i tried but after it idled for about 30 seconds, I turned it off and then started it again. The second time was 100% quick like normal. I just assumed the stumble to life the first time was from either a shortage of fuel or being flooded on fuel from trying to start it several times this morning with no luck. It's normal now though.... for now.
These cars don't flood. CoupeSedan gave you solid advice to check the CPS. It's $25-30 item, and I would replace it regardless if you don't know the condition of it. It may or may not be related to your start issue.
How high is the fuel level in your car at the moment?
These cars don't flood. CoupeSedan gave you solid advice to check the CPS. It's $25-30 item, and I would replace it regardless if you don't know the condition of it. It may or may not be related to your start issue.
How high is the fuel level in your car at the moment?
Ok. I'll run up the road and grab one so I can put it in tonight then. Better safe than sorry for $30.
Another update... The car started up on the first try this morning and I drove it to work. No issues. I haven't replaced anything yet. I ran out of time to mess with it last night. From what I've read though, it seems the CPS going bad would cause the failure to start after the car is already warmed up at running temp or stalling when coming to a stop at a light. Mine doesn't do either of those things. Mine happened on a cold starting in the am with a 60* outside temp. Wish I would have realized 100% whether or not the fuel pump was priming at that time. I dont think it was but I could be mistaken. If the fuel pump was priming, it could very well be the crank position sensor. If the fuel pump was not priming, that should tell me my issues is fuel related and not CPS related right? Would a failing CPS cause the fuel pump to fail to prime/come on?
Another update... The car started up on the first try this morning and I drove it to work. No issues. I haven't replaced anything yet. I ran out of time to mess with it last night. From what I've read though, it seems the CPS going bad would cause the failure to start after the car is already warmed up at running temp or stalling when coming to a stop at a light. Mine doesn't do either of those things. Mine happened on a cold starting in the am with a 60* outside temp. Wish I would have realized 100% whether or not the fuel pump was priming at that time. I dont think it was but I could be mistaken. If the fuel pump was priming, it could very well be the crank position sensor. If the fuel pump was not priming, that should tell me my issues is fuel related and not CPS related right? Would a failing CPS cause the fuel pump to fail to prime/come on?
I'll throw this out there for you: when my starter went bad, the car would occasionally crank but not start. Stop ignition sequence, have car start again, and then it would fire up. No fuel issue, no spark issue. Just acted odd. Almost felt like the car "missed its chance" to start in the first two seconds of cranking, and then the motor electronics cut the fuel.
So if its this kind of random, could be your starter going out too. I found out it was the starter when one day the starter groaned in a parking lot, and the car never started again until it was replaced. Never had the crank issue since.
Last edited by equitiesguy; 05-01-2020 at 02:23 PM.
I'll throw this out there for you: when my starter went bad, the car would occasionally crank but not start. Stop ignition sequence, have car start again, and then it would fire up. No fuel issue, no spark issue. Just acted odd. Almost felt like the car "missed its chance" to start in the first two seconds of cranking, and then the motor electronics cut the fuel.
So if its this kind of random, could be your starter going out too. I found out it was the starter when one day the starter groaned in a parking lot, and the car never started again until it was replaced. Never had the crank issue since.
Hmm... that's strange. Good to know though. I'll keep an eye on that as well. I guess I'm just more familiar with domestic cars in which a bad starter is a more obvious issue (sounds bad/rough/loud or just doesnt work at all).
Hmm... that's strange. Good to know though. I'll keep an eye on that as well. I guess I'm just more familiar with domestic cars in which a bad starter is a more obvious issue (sounds bad/rough/loud or just doesnt work at all).
In my case it was so weird I thought it was something with the Keyless Go, but it was the starter. No real indication of a bad starter before it failed. Depending on age/mileage, might want to factor that into the equation since you appear to have spark and fuel now without intervention. The only reason I mentioned about the fuel level is in case your pumps were too weak to pump fuel to the other side of the tank, but that isn't the case with your current situation of a minimum of 1/4 tank on that side.
04-30-2020, 08:26 AM
