96 C280 hard to start - PeachParts Mercedes-Benz Forum

steve dale · #1 07-29-2008, 03:51 PM

I own a 1996 C280 with 196,000 miles. I love the car! I have had very few issues with it, just the routine things. Recently I have had a hard time starting. I turn the key and the engine will turn over and over and over before igniting. I have changed the MAF two years ago. This took care of a missing problem. New plugs went in last summer, non platinum, along with new wires and connectors. This took care of acceleration and some missing also.
Not sure where to look with regards to this problem. It seems simple, but needs to be resolved quickly to keep the engine wear and tear to a minimum.
Please advise.
Thanks
Steve Dale
1996 C280
2001 E430

mpolli · #2 07-29-2008, 03:54 PM

Did you try doing a search?

Ethan · #3 07-29-2008, 08:35 PM

1) how old is your battery? how old is your oxygen sensor?

2)how oild is your fuel filter?

3)how old is your air filter?

Then you go down the line of what next for each category of fuel, air and ignition.

You need to visually inspect for torn rubber or loose electrical connections, then you need to use the search functon here as posted earlier.

I ask about the O2 sensor, because it would probably throw a code if bad, but I installed a new O2 sensor on my C230 and it starts so much better then before ( I have 108k miles )

mpolli · #4 07-29-2008, 09:58 PM

I don't see how those first 3 would cause his symptom (except the battery). The O2 shouldn't affect starting since it is cold and not doing anything at startup. The fuel filter would cause power problems not starting problems. Same for the air filter. Sorry I don't have a good idea of what it is though. I assume this car has no distributor. Assuming multi coils I would guess they all wouldn't fail at the same time. Have you scanned for codes? Is there any difference cold start vs. warm start? Weak battery would be a problem but I would guess he would be reporting slow cranking. Scan for codes.

Arthur Dalton · #5 07-29-2008, 10:01 PM

First suspect with you condition on that chassis is OVP relay...second is Crank Position sensor.

Next time condition exist, tap the OVP and retry to start.
Don't ask where it is cuz I don't know anymore , but the Archieves does....

Once you get to the Archieves , you will see that relay has been updated to a new part# and design to eliminate the originals faults.

crashone · #6 07-29-2008, 10:04 PM

I have better cold starts now after changing the fuel filter and sparkplugs. If all the other suggestions check out, try these.

Arthur Dalton · #7 07-29-2008, 10:07 PM

Crash is correct...the third suspect would be fuel and the test for that would be a simple fuel pressure test at the test port on the fuel rail...........

Also, if you are experiencing any flicker of the ABS indicator lamp , go right to the OVP diagnosis. OVP is power feed to BOTH ABS module and ECU, so ABS lamp is a tell...............[ but not always]
Your car is Full electronic, so it will not start without an OVP signal..[ whereas the earlier CIS would]

crashone · #8 07-29-2008, 10:14 PM

I don't have a way to check fuel pressure right now, I didn't know how old the filter was so I changed it. It needed it. I'm not sure how old the plugs were, but they looked tired......changed them too. Try some injector cleaner.

Ethan · #9 07-29-2008, 10:20 PM

www.club202.com has some good threads on OVP and Crank Angle Sensors.

mpoli - it's the craziest thing, I put in a new O2 sensor I my car starts quicker then I can remember. I used to think my Crank Angle Sensor was going south but since the new O2 the starting is amazing. Cold or Hot the starting is better. Of course I have no data or way to prove - or it could be coincidence

Arthur Dalton · #10 07-29-2008, 10:26 PM

Here is an old OVP testing post in the Archives ..it is a Highly Technical and Specific Procedure, but it has worked for many....

M104 Code 11 on pin 14 re-start problem

Arthur Dalton · #11 07-29-2008, 10:33 PM

<< Of course I have no data or way to prove - or it could be coincidence
>>

The 02 sensor is not active until the car goes into closed loop engine mangement, and that requires running until the sensor reaches 600 degrees F..... so I will go with the coincidence.

mpolli · #12 07-30-2008, 12:55 AM

I thought the crank sensors usually went bad at high temp. And his car does get started. Would a bad crank sensor act that way? I have no idea.

steve dale · #13 07-30-2008, 10:44 AM

I changed the ari filter this summer. The fuel filter is getting changed this week.
I do, on occasion, have the ABS light come on. Usually during warmer weather.
Having looked further on this expense saving board, I suspect the OVP. I am in the process of purchasing a new one this week. I will install, along with the fuel filter, this week.
I believe this is the main culprit.
I will inform later.
Thanks again for the input.
Steve Dale

1996 C280
2001 E430

Arthur Dalton · #14 07-30-2008, 12:44 PM

Check the OVP part# on the side..see if it is the Original one...the new modified version has a different #.

< [ By Siemens] ................ Replaced by 000-540-67-45>>

steve dale · #15 08-29-2008, 02:10 PM

Well, I changed the OVP. No change. Now I think it maybe the fuel relay.
What are your thoughts?
Steve Dale
1996 C280
2001 E430