Please help. Engine starting problem
Thread Starter
Newbie
Joined: Jul 2013
Posts: 4
Likes: 0
99 C280
Please help. Engine starting problem
Hello. I have a 99 C280 and am having problems getting the engine to turn over. It acts like it is trying to start. If I put a little gas in the air intake, it runs like normal for up to 10 seconds. I have fuel coming to the fuel rail, and spark since it turns over when I put gas directly into the intake. There is also a loud whirring/buzzing sound coming from the throttle body. The fuel gauge needle is still jumpy for a few seconds even after replacing the sending units. I have replaced the crankshaft sensor, fuel pump and filter, and both sending units. Any help would be appreciated.
Last edited by jameshigdon100; Mar 15, 2016 at 06:51 PM. Reason: Left out info
Junior Member
Joined: Jul 2015
Posts: 24
Likes: 1
From: Baton Rouge, LA
'98 E430
My car has an anti-theft device, which allows the engine to crank and it even sounds like it starts for a moment, but it won't run. If you spray some ether in, it will run for a few seconds before it quits. I didn't know about this feature, but it screwed me over two separate times.
So, if your car thinks it is locked, the feature kicks in. My car has a red and green light on the rear view mirror. Use the key fob and make sure the green light is on, not the red. In my case, the car started instantly when it was green versus red.
This may not be your problem, but I know it was mine 2 separate times til I learned about it.
So, if your car thinks it is locked, the feature kicks in. My car has a red and green light on the rear view mirror. Use the key fob and make sure the green light is on, not the red. In my case, the car started instantly when it was green versus red.
This may not be your problem, but I know it was mine 2 separate times til I learned about it.
Thread Starter
Newbie
Joined: Jul 2013
Posts: 4
Likes: 0
99 C280
Still no luck on getting it to start. I have tried locking and unlocking the door. I have tried pointing the key fob at the mirror and pressing the buttons. It seems it is not an uncommon problem. However, could it be a problem with the fuel injectors or a relay? I don't know which relay operates the fuel injectors though.
Super Member
Joined: May 2002
Posts: 540
Likes: 39
From: Suburban Washington DC
1995 S280 5-speed
You need to get a fuel pressure tester gauge to plug into the fuel rail. You're just chasing your tail until you know what that pressure is. I had the same symptoms last week on my 94 that's been sitting a while. Checked the pressure and it was near zero. Went to the hassle of removing the fuel pump, but when no gas spilled out, I knew it was out of gas even though the gauge said otherwise. Even put power to the pump and it worked fine. Put everything back together and filled it with 5 gallons. Cycled the pump a few times and saw the pressure gauge go up to normal. Started right up.
Thread Starter
Newbie
Joined: Jul 2013
Posts: 4
Likes: 0
99 C280
I got it running. The new crank sensor I bought was faulty. Then, the new fuel pump ruptured one of the rubber fuel lines. But, now it is mostly good. The fuel gauge is not accurate still...even though I just replaced both sending units. I'll have to see if they need to be syncronized or something in the computer.
