1976 W114 won't accelerate on hard acceleration and hills - Mercedes-Benz Forum

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old 11-01-2012, 04:13 PM Thread Starter
BenzWorld Newbie
 
Date registered: Nov 2012
Posts: 4
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
Exclamation 1976 W114 won't accelerate on hard acceleration and hills

Hello people! I'm Nate and brand new to the forum. First time Mercedes owner as of just over a month now. I can't be happier with my W114, but she is one high maintenance little girl.

I am need of some advice. I have had my 1976 W114 in the shop for the past 4 days for the same problem. It has even stumped my mechanic(Stu Ritters Mercedes). Great guy, seems to know his cars, but can't seem to find a solution to my problem. The problem is when I put the pedal to the floor the car will lose oil pressure and appear to die out. If I let off the gas oil pressure returns to normal, I then can give it gas and it will accelerate fine. There are actually three separate occasions in which this problem happens: 1)Hard acceleration 2)Coming out of a turn and gentle acceleration 3)Hills when coming out of either a dead stop or at a slow speed.

Here's what has been done: 1)Replaced fuel filter(gas is clean/tank is clean) 2)Ran a cleaner through the system(I'm not sure what he put in it) 3)Who knows what else he did to diagnose the problem, but we are without a solution

Information that may help. This is a California Emission 280 inline 6cyl, which means it has a lot of other emissions equipment on it. My mechanic said that it is more than likely either a catalytic converter problem or a carburetor problem. My feeling it's more carburetor than catalytic converter due to the problem occurring when accelerating out of a turn and when accelerating up a hill from a stop. Maybe I don't understand enough about my set-up, but I don't see a catalytic converter being the cause. But then again it could be getting the fuel it needs, but not the air. What are your thoughts?
RoughDrapht is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 11-01-2012, 04:18 PM
BenzWorld Member
 
Date registered: Oct 2012
Vehicle: '73 280C
Location: OC, CA/Bozeman, MT
Posts: 137
Mentioned: 0 Post(s)
Quoted: 2 Post(s)
Carb or accelerator pump. Mine had a similar issue to a lesser degree. Was a combo of bad pump and poor tuning.
ssk831 is offline  
post #3 of 12 (permalink) Old 11-02-2012, 09:51 AM
BenzWorld Member
 
Date registered: Feb 2011
Vehicle: 1973 220D
Location: California
Posts: 295
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
Quote:
Originally Posted by RoughDrapht View Post
Here's what has been done: 1)Replaced fuel filter(gas is clean/tank is clean)

...

What are your thoughts?
I don't know (but when has that ever stopped me?) but doesn't this car have two fuel filters? One is the simple plastic in line thing and the other is a bigger thing in a metal canister. Perhaps your man replaced that one too - but worth asking.
frankflynn is offline  
post #4 of 12 (permalink) Old 11-24-2012, 12:28 AM
BenzWorld Junior Member
 
Date registered: Jan 2012
Location: NE corner of the 4 corners
Posts: 47
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Send a message via Skype™ to An.vil
I strongly suggest replacing the main fuel filter (the can style) it happened couple of times with mine. Advance auto parts had it for less than $10 and car worked perfectly right after exchange.


W115 1975 300D (entertaining reasonable offers)
An.vil is offline  
post #5 of 12 (permalink) Old 11-24-2012, 11:26 AM
Premium Member
 
Date registered: Nov 2012
Posts: 1,241
Mentioned: 0 Post(s)
Quoted: 59 Post(s)
Premium Member
this a m110 engine , does this problem occur when the gas tank gets below 1/2 ???? .there was a problem on those carb where the needle seat would be loose [ press fit ] , this would cause the fuel to shut off . the other problem was that the float chamber of the carb is vented thru a vacuum controled valve assembly , this , when malfunctioning would under hard acceleration cause a vacuum to be present in the float chamber , this would act like fuel starvation .i used to disable this system by swithing a spring position in the carb float chamber vent valve . this valve [ part of the cab top ]connect to the charcoal cannister . this valve if i recall should be open when engine if off , to vent the fumes into cannister , but MUST be closed with engine running .it s been a while since i have seen a carb m 110 .
agillot is offline  
post #6 of 12 (permalink) Old 11-24-2012, 11:31 AM
Premium Member
 
Date registered: Nov 2012
Posts: 1,241
Mentioned: 0 Post(s)
Quoted: 59 Post(s)
Premium Member
i forgot one thing , does the needle assembly in the second stage lift when you push open the secondary flaps by hand , also the 2 flaps are spring loaded , this is a very light spring loaded action , adjust this tension firmer , more tension . if the 2 needles dont lift when you push the flaps down , there is a bad plastic cam in there .hope this help .
agillot is offline  
post #7 of 12 (permalink) Old 11-25-2012, 11:54 AM
BenzWorld Extremist
 
kavadarci's Avatar
 
Date registered: Aug 2008
Vehicle: 1971 250C
Location: Toronto, Canada
Posts: 1,056
Mentioned: 0 Post(s)
Quoted: 14 Post(s)
this sounds like my problem.
what i found is the carb black membrane was torn in one place and once there is need for more fuel it will loose pressure and the car will not go.

once replaced this puppy was a rocket.
kavadarci is offline  
post #8 of 12 (permalink) Old 07-04-2013, 10:04 AM Thread Starter
BenzWorld Newbie
 
Date registered: Nov 2012
Posts: 4
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
Here's an update. I know it's been months, but Stu Ritter had me get a second opinion. I ended up taking the car to 5601 Garage back in November and they told me it was loss of compression. I took their word and ended up parking the car in my garage until I found the time to rebuild. Well that time came and I began thinking a third opinion might be best so I had it towed to German Motors inc.

Let me just say that if you have W114 with the solex carb and are in Colorado they are the place to take your car. They had me back up and running after about 2 hours of adjustments. Agillot it appears you were right.

I've now run into another problem of it passing emissions. It's running better than it ever had but it's at 6.49 on the CO2 emissions, when I'm only allowed a 2. So I'm running really rich. Not sure if this is because of poor tuning or if it is in fact a problem with the catalytic converter. Like I said the car runs great, but if they tune it down and if it gets less fuel I worry it'll run poorly again.

Any thoughts would be great.
RoughDrapht is offline  
post #9 of 12 (permalink) Old 07-04-2013, 04:54 PM
BenzWorld Extremist
 
kavadarci's Avatar
 
Date registered: Aug 2008
Vehicle: 1971 250C
Location: Toronto, Canada
Posts: 1,056
Mentioned: 0 Post(s)
Quoted: 14 Post(s)
Do you need to pass emission for such an old car? There is no such thing in Canada the car is too old to meet the new standards as you found yourself



Sent from AutoGuide.com Free App
kavadarci is offline  
post #10 of 12 (permalink) Old 07-04-2013, 05:30 PM Thread Starter
BenzWorld Newbie
 
Date registered: Nov 2012
Posts: 4
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
(Thread Starter)
If it was a '75 I'd be able to register it as a classic here in Colorado and wouldn't need to pass emissions. I don't know why they chose '75 to be the cut off year, but it is what it is. An option that came to mind is just running the car with half a tank of E85 to make it lean. Not sure if that's wise with these motors or not.
RoughDrapht is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > General Mercedes-Benz Forums > Vintage Mercedes-Benz

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
     
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode



    Posting Rules  
    You may post new threads
    You may post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On

     

    Title goes here

    close
    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome