Mercedes-Benz Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1
Hello all, I am new to this site and want say thanks for any info and help beforehand.
I'll try to keep this as detailed but as short as possible.......
My problem all occurred all in one day, car stalled at stops 3 times, all within 30 minutes. First time it started back up in about 30 seconds, second time it took about 2 minutes, and third time it started the next day (i left it and came back so it may have started sooner). After researching for a few days I came to the conclusion it was the crank position sensor. I replaced it and still no start. The fuel pump is "engaging" but only if you crank the car. What I'm saying is on "first try" to start the car you can hear the pump engage once the key is in the on position but if you do not fully turn the key to start the car and you turn the key back to the "off" position and then turn the key again to the on position the pump does not engage. The pump will only engage again if you try to crank the engine. Is that normal on the c280, as I know that is not the case with my other vehicles.
I did try to sand the small terminals on the fuel pump relay as was mentioned in another post. It did seem that the car seemed to wanna start a couple times after doing so but it did not.
Also there is a port on the throttle body (about a 1/2 inch in diameter and 1 inch long) positioned at about 1 o'clock when looking at it from the front of the car that I noticed had nothing running to it. Should this have a vac line going to it or possibly just need to be capped off?

Again, Thanks and any help is much appreciated.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #3
Car started and but died quickly when using starting fluid......unplugged MAF and car started right up....shut car off, plugged MAF back in and it started right up, started to set MAF on Throttle body and car died. Now it will not start with MAF plugged in or unplugged???
 

·
Registered
Joined
·
880 Posts
First, spray starter fluid after the MAF, and don't use a lot. It will wash oil from the cylinder walls.

Did you try ether again? It should only run for a second or so, but the purpose is just to show you have ignition.

The fact that it ran after you did this and that may just mean you have something intermittent in the fueling circuit.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #5
Sorry for the delay I have been out of town. Yeah it did only run for a second or two with starting fluid. After trying it with starting fluid (directly into TB) I unplugged the MAF as stated in my last post and thats when it started up fine with no starting fluid. Any other specifics I can check to eliminate different possibilities? Thanks much for your time.
 

·
Registered
Joined
·
4,103 Posts
Also there is a port on the throttle body (about a 1/2 inch in diameter and 1 inch long) positioned at about 1 o'clock when looking at it from the front of the car that I noticed had nothing running to it. Should this have a vac line going to it or possibly just need to be capped off?
Picture?
 

·
Banned
Joined
·
3,373 Posts
I would check the "Cam sensor"

Its located on the front of the engine head, and looks basically similar to the Crank Shaft Position sensor..

They not too expensive at all..

Cam Sensor - activates fuel pump to pump fuel according to the engines needs. (As far as I understand it)

Your car has fuel problem.. Just my 2 cents
 

·
Registered
Joined
·
17 Posts
Discussion Starter #9
MafiaDON...pretty good 2 cents you put in...Prior to reading your message today the car decided to run and I headed to the parts store to see what codes it is throwing and of course it quit on me about 100 yards from the parts place so had to have it towed but tow guy swung it by the parts store first and your right cam sensor and coolant temp sensor...does anyone know if the 97 c280 should have the same sensors in both ports of the throttle body housing?
 

·
Banned
Joined
·
3,373 Posts
cam sensor and coolant temp sensor...does anyone know if the 97 c280 should have the same sensors in both ports of the throttle body housing?
The coolant sensor will only make the temp gauge fail, and possibly allow the vehicle to over heat if it does not trigger the AUX fans at a certain temp. BUT, it will NOT prevent the car from starting..

The Cam sensor will. (Saw a similar case on an Audi A6 Quattro).. Just replace the Cam sensor (refer to pic for location.)

What does the throttle body have to do with the Cam sensor? The Cam sensor is on the front of the front of the engine as I mentioned earlier.

All the best! lets hope thats the only issue preventing the car from starting..
 

Attachments

·
Registered
Joined
·
2 Posts
Check the immobiliser

Just my tuppence worth...

I had a similar problem, after lots of head scratching and replacing parts it turned out I just needed to resync the key...

Do you hear rattling sound if you shake your key fob, if so its probably a loose RFI chip. Open your key fob and stick it back in place with double sided tape.

If not, resync your key by holding it up to the mirror, pressing the unlock button twice (some models need you to hold the button down) until the red and green lights begin to flash rapidly. Then place your key into the ignition and turn to position 2. (I believe '94 and later models need you to start the motor).

Try this and see if it works.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #13
Does anyone know if this could be a problem with the cam adjuster magnet? ODBII said code P0345 cam shaft position sensor A Bank 1. I replaced the cam shaft sensor but it still will not start.
 

·
Banned
Joined
·
3,373 Posts
Possibly the ECU? Or other engine control module.. Check those
 

·
Registered
Joined
·
17 Posts
Discussion Starter #15 (Edited)
ok guys im finally back home and have some time to work on this car...i got a fuel pressure gauge (one that works this time)..lol...i just checked the pressure and its just under 50psi with vac line on regulator....any suggestions on what to try now? thanks much...pulled all 3 coil packs and they are all reading about 9 ohms.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #17
it will not start so until it changes its mind i cant check it while running but yes i can if it does decide to start...whats the easiest way for me to test the fuel pump if the car will not start?
 

·
Registered
Joined
·
17 Posts
Discussion Starter #18 (Edited)
So these are my thoughts so far.....when running the car runs smooth..ruling out MAF, coils, plugs and wires? Checked fuel pressure and its right under 50psi. I bypassed the fuel relay (able to hear fuel pump constantly running) and it started, then I shut it off and put relay back in and it started, I shut if off 5 or six times and it continued to start so I let it run for about 10 mins and then drove 2 mins down road and on the way back the rpms bounced just a little at stop sign by house then 5 secs after pulling off from stop sign it stalled pulling into my driveway. Now it will not start with relay in or bypassed. I tried to start with starting fluid and it would still not start. I did not check fuel pressure while it was running because I thought I had found the issue to be the fuel relay acting intermittently. Any thoughts on this demon?
 
1 - 19 of 19 Posts
Top