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 ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 10-14-2002, 06:48 PM
lombrozo
Guest
 
Posts: n/a
Low manifold vacuum 1978 280SE

Hi guys: I have a California 1978 280SE W116.024, M110, K-Jetronic.
I have good compression, and it runs fine although the idle is very lumpy. Power is good.
Manifold vacuum at idle is only about 9 inches; even goosing the throttle and releasing does not bring it above 15 inches.

I have been unable to find an intake leak, using unlit propane torch or carb spray.

I have systematically disabled all the vacuum consumers that I can find - transmision modulator, ACC, distributor, door locks, power brakes; I have disabled the EGR, even remving and blocking its attachment to the intake manifold.

I am measuring vacuum both at the connection for the ACC/door locks, and I tapped into the line to the warmup compensator, they read the same.

I had to remove and replace the cams, had a flat lobe that was welded and reground (by a reputable cam grinding shop).

I aligned the cams properly, although looking at the marks, I thought I might be less than one link off from perfect - did not put in an offset woodruff key.

Valves are adjusted and fairly quiet. Exhaust is all new. As I said, power is good and mileage is about 18MPG in country driving.

I have done the pressure testing of the K-Jetronic system, everything is in order now that I installed a check valve at the fuel pump. Starts instantly hot or cold; fast idle warmup is good.

Just a lumpy idle and low vacuum. Any ideas?
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 12:34 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page