Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 02-08-2007, 12:46 AM
Registered User
 
Join Date: Apr 2006
Location: Mountain View CA.
Posts: 74
420 SEL Poor Acceleration

Hi All,

I just had the timing chain and exhaust replaced as well as a tuneup on my 1988 420 SEL. The mechanic is having a hard time getting the car to run well. When the accelerator is depressed the car barely goes. It seems as though the harder the pedal is pressed the slower the car goes. The car sat for years and was running poorly when I brought it in. I had been told that the catalytic converter was clogged. The car runs worse than when it was brought in but it idles well now. Your help would be greatly appreciated.

Reply With Quote
  #2  
Old 02-08-2007, 01:26 PM
Registered User
 
Join Date: Aug 2006
Posts: 195
i have a 560sel with similar problem.once i changed the timming chain i had to adjust my timing since the other chain was slipping. i just turned the distributor some and the power returned.not the most high tech way but it worked.
Reply With Quote
  #3  
Old 02-08-2007, 01:37 PM
Registered User
 
Join Date: Aug 2006
Posts: 141
420sel

A clogged cat will give the symptoms you describe. Try driving the car with the cat loose and see if the power comes back.
Mike
Reply With Quote
  #4  
Old 02-08-2007, 02:17 PM
Tomguy's Avatar
Vintage Moderator
 
Join Date: Aug 2002
Location: near Scranton, PA
Posts: 5,411
If the chain had a lot of stretch, you may need to retime it as johnlo suggested. The distributor is driven by the timing chain. When you say it goes slower does it sputter or just not speed up? And is this in park or drive? A complete lack of power usually means a very, very retarded ignition timing.
__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k
Reply With Quote
  #5  
Old 02-08-2007, 02:17 PM
Registered User
 
Join Date: Apr 2006
Location: Mountain View CA.
Posts: 74
The timing was set and the entire exhaust and cat were replaced
Reply With Quote
  #6  
Old 02-08-2007, 02:56 PM
dkveuro's Avatar
Sword of Damocles
 
Join Date: Jun 2003
Location: Here an' there.
Posts: 2,548
Low fuel pressure or fuel not being delivered by CIS-e distribution head.
Have the O2 monitored...at WOT it should read 0.980vdc to 1.02vdc,
any lower indicates very lean .



.
__________________
[http://languageandgrammar.com/2008/01/14/youve-got-problems-not-issues/ ]

"A liberal is someone who feels they owe a great debt to their fellow man, which debt he proposes to pay off with your money."
Reply With Quote
  #7  
Old 02-08-2007, 03:21 PM
david s poole
 
Join Date: Mar 2005
Location: dallas
Posts: 1,822
are you sure that the mechanic set the timing up right[valve timing]?it is easy to make a mistake if you are not familiar with these engines and their quirks.drivers side cam sprocket has a timing washer that has the mark on it it has two keyway slots one top and one bottom if washer falls off and you didn't see it it can be put on upside down and will change the firing order on the left bank.call me if you need to.
__________________
David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
http://www.w108.org/gallery/albums/A...1159.thumb.jpg
Reply With Quote
  #8  
Old 02-08-2007, 05:07 PM
Registered User
 
Join Date: Apr 2006
Location: Mountain View CA.
Posts: 74
Thanks for your responses and David, thank you for your kind offer. I will relay the information to my mechanic and see if it helps. I also can describe the behavior in a little more detail; The car idles smoothly but acceleration is rough. Light depression of the accelerator yields better (still bad) response. Depressing the pedal significantly has an opposite effect from normal. It seems as though the engine pulls less the more the pedal is depressed.
Reply With Quote
  #9  
Old 02-08-2007, 07:05 PM
just-n-time's Avatar
Registered User
 
Join Date: Feb 2006
Location: Louisiana266 Maloy Rd winnfield71483
Posts: 804
Your eng. is out of time on that one bank,OR you are so dry roted from age and have massive air leeks at the intake system! but I think Dave hit it hard.

Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 04:18 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page