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 10-14-2016, 02:42 PM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,544
M103 starting poorly still: Fuel pumps not priming?

I have been chasing the starting issues on my 190E for several months now and haven't driven the car in a couple of weeks because it is an inconvenience to have to take 2 minutes to get it to start and run well enough to pull out of the driveway. I have tried so many things but had an idea last night: maybe the fuel pumps aren't priming.

It takes about 15-20 seconds of cranking to get it to sputter to a start and idle at 450rpm then has to run for about a minute before I can move it without it stalling. Once it warms up, it runs like a M103 typically does, like a slouch in the low end and better in the upper end. I tried to hear the pumps priming last night as I cycled the key on and off but couldn't hear them though I could hear them on my parts car back when that still had the engine in it. Is it possible that the pumps are not priming in the "run" position of the ignition but starting to pump once I put it into the crank position? Is there a good way to test this theory?

__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #2  
Old 10-14-2016, 03:07 PM
Registered User
 
Join Date: Feb 2011
Location: Modesto CA
Posts: 2,966
Quote:
Originally Posted by w123fanman View Post
Is it possible that the pumps are not priming in the "run" position of the ignition but starting to pump once I put it into the crank position? Is there a good way to test this theory?
Method I -
Hook up a test light to the pumps, with leads that are long enough for you to see the light when you are seated in the car. Then cycle the key; the light should be on for 2-3 seconds per cycle.

Method II -
Have another person cycle the key while you listen under the car close to the pump location.
Reply With Quote
  #3  
Old 10-15-2016, 02:27 PM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,544
Quote:
Originally Posted by Frank Reiner View Post
Method I -
Hook up a test light to the pumps, with leads that are long enough for you to see the light when you are seated in the car. Then cycle the key; the light should be on for 2-3 seconds per cycle.

Method II -
Have another person cycle the key while you listen under the car close to the pump location.
I listened to it, it was extremely quiet and only cycled for about 1/4 second. I'm assuming that's not right?
__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #4  
Old 10-15-2016, 02:57 PM
Registered User
 
Join Date: Feb 2011
Location: Modesto CA
Posts: 2,966
Quote:
Originally Posted by w123fanman View Post
I listened to it, it was extremely quiet and only cycled for about 1/4 second. I'm assuming that's not right?
Not right, indeed. Look to the fuel pump relay as the most likely culprit. If you are so inclined, after removing the relay from its socket, pop off the cover, and carefully examine all the solder joints and traces. Cracked and/or cold solder joints occur quite frequently.

When the relay is out, jumper circuit 30 to circuit 87 (typically pins 7 & 8). The pump should run continuously, and the engine should start promptly.
Reply With Quote
  #5  
Old 10-16-2016, 06:17 AM
oldsinner111's Avatar
once a happy man
 
Join Date: Nov 2008
Location: bristol,tn
Posts: 5,719
does this car have a cold start injector?
__________________
only people with alot of possesions afraid of death, a poor man looks forward to end misery
Reply With Quote
  #6  
Old 10-16-2016, 07:21 AM
optimusprime's Avatar
Trevor Hadlington
 
Join Date: May 2014
Location: Worcestershire in England
Posts: 1,295
Link number 7 and 8 on the fuel pump relay with copper wire , it will then run all the time .So remove the wire after you have done it .If you dont it will flood the engine...
Reply With Quote
  #7  
Old 10-16-2016, 09:30 AM
Registered User
 
Join Date: Mar 2003
Location: Southern California
Posts: 2,154
Search for a thread stated by me: Fuel accumulator failure analysis and run the simple on-the-car test. This component is often overlooked, but given you symptoms, it's the number one suspect.

Duke
Reply With Quote
  #8  
Old 10-16-2016, 10:55 AM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,544
Quote:
Originally Posted by oldsinner111 View Post
does this car have a cold start injector?
Yes it does. I have been trying to find out information on how to test it but still not sure what to do.
__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #9  
Old 10-16-2016, 10:56 AM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,544
Quote:
Originally Posted by Duke2.6 View Post
Search for a thread stated by me: Fuel accumulator failure analysis and run the simple on-the-car test. This component is often overlooked, but given you symptoms, it's the number one suspect.

Duke
Your symptoms sound a lot like mine though it has to have been sitting at least a few hours before it has problems starting again.
__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #10  
Old 10-18-2016, 11:42 AM
Registered User
 
Join Date: Mar 2003
Location: Southern California
Posts: 2,154
That's typical. A small crack in the diaphragm as in the photo attached to the thread I recommended you review will cause the accumulator to bleed down slowly and take time to fill up the leaking accumulator to build fuel pressure during cranking.

It sounds like do didn't look up the thread I recommended... your choice.

Duke
Reply With Quote
  #11  
Old 10-18-2016, 01:28 PM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,544
Quote:
Originally Posted by Duke2.6 View Post
That's typical. A small crack in the diaphragm as in the photo attached to the thread I recommended you review will cause the accumulator to bleed down slowly and take time to fill up the leaking accumulator to build fuel pressure during cranking.

It sounds like do didn't look up the thread I recommended... your choice.

Duke
I did, which is why I said your symptoms sound similar but not the same. I'm going to test it later this week.
__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #12  
Old 10-23-2016, 02:29 PM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,544
I removed the rubber line from the outside side of the fuel accumulator and pulled vacuum on it and got 40ml of gas in my catch can. It then held vacuum fine. I think it is probably fine. Next, I'll test the cold start injector.


I also tried the clear line plus priming the system, didn't seem to do anything but I had already pulled all of the residual fuel out of the accumulator.
__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #13  
Old 10-23-2016, 03:46 PM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,544
Injector tested at 10.6 ohm, did not fire with the engine cold but it's about 70F out here. Should it fire when it is this warm?
__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #14  
Old 10-23-2016, 11:35 PM
w123fanman's Avatar
Registered User
 
Join Date: Jun 2011
Location: Georgia Tech, Atlanta, GA
Posts: 1,544
Injector sprayed when jumped. The plug was only giving it about 2 volts. I have ordered a rebuilt MAS relay that was on ebay for $40, ordering an OVP relay since it's cheap insurance, and a new CIS coolant temp sensor.
__________________
80 300SD 183K
83 300D manual 100K chassis
86 Yugo GV 48K
88 Yugo GVX 9K
90 300D 230K
90 Lexus LS400 189k
91 F150 4.6 4v 160K
93 190E 3.0 Sportline Limited Edition 230K
93 190E 2.6 Sportline Limited Edition 91K
96 MGM LS 242K- RIP
03 Sprinter Passenger 220K
06 MGM LS 105K-sold
Parts cars:
77 240D Auto-RIP
79 300SD- RIP
80 300SD
83 240D-RIP
85 240D-RIP
87 190D-RIP
91 190E 2.3- RIP
93 190E 2.6-RIP
Reply With Quote
  #15  
Old 10-24-2016, 01:33 PM
Registered User
 
Join Date: Mar 2003
Location: Southern California
Posts: 2,154
[QUOTE=w123fanman;3647697]I removed the rubber line from the outside side of the fuel accumulator and pulled vacuum on it and got 40ml of gas in my catch can. It then held vacuum fine. I think it is probably fine. QUOTE]

Your test is not clear to me, but it's not the test I recommended to check for a leaky fuel accumulator diaphragm.

Duke

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 02:20 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page