'68 250 SL - Hard start...lurching/lunging/sputtering engine?????? - Mercedes-Benz Forum

 
LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old 07-22-2002, 02:26 PM Thread Starter
BenzWorld Newbie
 
Date registered: Dec 1998
Posts: 0
Mentioned: 0 Post(s)
Quoted: 2 Post(s)
(Thread Starter)
'68 250 SL - Hard start...lurching/lunging/sputtering engine??????

My SL has sat for about 9 months w/just some occasional start-ups.<br> <br> The engine was totaly rebuilt in '94, and has about 2500 miles on it since. Compression on all cylinders is high and all are even, as tested about a year ago. The engine usually starts up, is a bit rough, but settles to idle after you run it for a while.<br> <br> However, it took about 2 minutes of constant cranking to get it started recently. Then it kept stalling. I got it going again, but it felt like the engine was lurching and lunging, and could not stay running unless I put the gas down at least half way, and had it at 3000+ rpm.<br> <br> The radiator was flushed last fall, and the collant, oil levels are fine. The car will move under its own power, and is mooter in neutral.<br> The only thing that has happened, is the rubber ring that holds the muffler up at the back of the car broke, and the muffler was hanging down for a while. I attached a ring to hold it up for now. But, I am not sure if the muffler pipes or manifold connectors might have bent or twisted causing a problem with the exhaust output.<br> <br> Any guesses welcome....is this lunging/lurching a sign of a bad fuel injection pump, water pump, fuel pump, bad gas???<br> <br> Thanks!
Guest (MBNZ) is offline  
Sponsored Links
Advertisement
 
post #2 of 5 (permalink) Old 08-12-2002, 11:07 AM
BenzWorld Newbie
 
Date registered: Aug 2002
Vehicle: 1968 250SL
Location: Gilbert, Arizona
Posts: 4
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
I had a similar problem a while back and ended up havin the the injector pump rebuilt. Ru...

I had a similar problem a while back and ended up havin the the injector pump rebuilt. Runs like a charm now. I would definitel look down this road. I would start at the fuel pump and work my up.

Randy Corral
68mercedes is offline  
post #3 of 5 (permalink) Old 08-28-2002, 12:38 PM
BenzWorld Member
 
MercedesMax's Avatar
 
Date registered: Aug 2002
Vehicle: 280SL Pagoda, BMW318
Location: Shropshire, United Kingdom
Posts: 98
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Italian tune ups work wonders

Quote:
My SL has sat for about 9 months w/just some occasional start-ups.<br> <br> The engine was totaly rebuilt in '94, and has about 2500 miles on it since. Compression on all cylinders is high and all are even, as tested about a year ago. The engine usually starts up, is a bit rough, but settles to idle after you run it for a while.<br> <br> However, it took about 2 minutes of constant cranking to get it started recently. Then it kept stalling. I got it going again, but it felt like the engine was lurching and lunging, and could not stay running unless I put the gas down at least half way, and had it at 3000+ rpm.<br> <br> The radiator was flushed last fall, and the collant, oil levels are fine. The car will move under its own power, and is mooter in neutral.<br> The only thing that has happened, is the rubber ring that holds the muffler up at the back of the car broke, and the muffler was hanging down for a while. I attached a ring to hold it up for now. But, I am not sure if the muffler pipes or manifold connectors might have bent or twisted causing a problem with the exhaust output.<br> <br> Any guesses welcome....is this lunging/lurching a sign of a bad fuel injection pump, water pump, fuel pump, bad gas???<br> <br> Thanks!
Given the car has been sitting idle quite a bit it's possible the fuel is fowl or that it just needs a good clean out. These cars need to be run regularly if you can to keep everything working (fuel inj pump included).

My recommendation before you go wasting money is to give it a reeeaaaaalllly good run. Throw a can of decent fuel injector cleaner in, warm it up nicely, and floor the daylights out of it to blow all of the crap and cobwebs out - this is especially needed if the car is driven gently all of the time.

If this doesn't work, you may then have to spend some money,

MercedesMax
Shropshire, UK.

280SL Pagoda
BMW 318i SE
Seeking rare, reliable E Class CDI!
MercedesMax is offline  
post #4 of 5 (permalink) Old 10-02-2002, 05:39 PM
BenzWorld Senior Member
 
Greg S.'s Avatar
 
Date registered: Aug 2002
Vehicle: 85 300GD LWB
Location: Newfoundland, Canada
Posts: 501
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Send a message via MSN to Greg S.
Don't run your starter continuosly for 2 minutes!! I assume you didn't but just thought to...

Don't run your starter continuosly for 2 minutes!! I assume you didn't but just thought to add my 2 cents worth.

As for the rough running, have you checked your ignition system? Can you get a sample of your fuel before it gets to the IP? You may find crap or likely water in your fuel. Dump some methyl hydrate in the tank and see if that clears it up. Best of luck!

Greg S.
'86.5 Porche 928
'85 300GD
'73 Unimog 416 Doka
'73 Unimog 406 AG
'63 Unimog 404 (sold)
Greg S. is offline  
post #5 of 5 (permalink) Old 01-21-2003, 09:13 PM
BenzWorld Junior Member
 
Date registered: Aug 2002
Vehicle: 450 SL, 230 SL
Location: Massachusetts
Posts: 13
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
I just got a 64 230 SL which exhibited a similar problem. Hard starting, backfiring, rea...


I just got a 64 230 SL which exhibited a similar problem. Hard starting, backfiring, really having to nurse the thing along until warmed up. While checking for non-firing cylinders, I discovered a lot of leakage in the plug wires. After replacing them (and the plugs), it starts well and runs very smoothly. I don't know if sitting unused can cause deterioration of the plug wires, but it is sure worth checking out before you mess with the fuel system.

Good luck !

Chris Ryan
ryan28@charter.net
1975 450 SL
1964 230 SL
Chris Ryan 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