280e fuel pressure problems

1968 - 1976: 220, 220D, 230, 230.4, 230.6, 240D, 250, 250C, 250CE, 280, 280E, 280CE, 300D
Post Reply
User avatar
1973_280E
A Class
Posts: 13
Joined: Wed 27 Jul, 2005 3:57 pm
Model you own: w114
Location: Brisbane, QLD

280e fuel pressure problems

Post by 1973_280E »

I'm at the tail end of a full engine reconditioning process for my w114 280E M110. Going through the engine testing phase we have found the fuel to be a bit lean. The 280E has 2 fuel regulators from what I can gather (one for in flow and one for out flow), making it difficult to tune the fuel pressure correctly.

I find that all the manuals available to me go out of their way to avoid the 280E fuel and injection system... so annoying!

Has anyone else had a similar experience in adjusting fuel pressure on this engine model? Anyone have some data on seting the pressure between the two regulators?
User avatar
OzBenzHead
300 SLR
Posts: 2140
Joined: Mon 22 Aug, 2005 9:11 am
Model you own: w126
Region: New South Wales
Location: NSW Central West

Post by OzBenzHead »

G'day, 280E :)

Might be worth trawling through this manual: http://handbook.w116.org/.

Sure, it's for the W116 mostly, but it covers the M110 with both D-Jetronic and K-Jetronic systems.

Good luck.
OzBenzHead
Currently:
1983 C126 500 SECBruno
2003 BA Falcon ute 4.0L Barra 182Henry
Formerly:
1955 W180 220a – Ponty
1964 W112 300 SE/C – Béla
1965 W111 220 S – Hektor the Heckflosse
1970 W108 280 SE – my first Benz – Karl
1973 W116 280 SE Crayford Estate – der Rolfwagen
1975 W116 450 SE – Goldy Horn a.k.a. Thirsty Merc
1980 W116 280 SE – Boris
1989 W124 300 E – Hester
1992 W201 180 E – Babe I
1992 W201 190 E 2.0 – Babe II
+ numerous W108/116 rolling spares
Prior to my M-B epiphany:
53 cars including many British oil-leakers (e.g. 14 P4 / P5 Rovers!), frequently cursed by Lucas the Prince of Darkness. Learnt to drive grey Fergie tractor and '27 Nash paddock-basher ute aged 8. First car owned (age 13): 1953 Fiat 500.
User avatar
Nutz
E Class
Posts: 74
Joined: Fri 30 Dec, 2005 8:44 pm
Model you own: w116
Location: Hawaii [ Maui ]

Re: 280e fuel pressure problems

Post by Nutz »

1973_280E wrote:I'm at the tail end of a full engine reconditioning process for my w114 280E M110. Going through the engine testing phase we have found the fuel to be a bit lean. The 280E has 2 fuel regulators from what I can gather (one for in flow and one for out flow), making it difficult to tune the fuel pressure correctly.

I find that all the manuals available to me go out of their way to avoid the 280E fuel and injection system... so annoying!

Has anyone else had a similar experience in adjusting fuel pressure on this engine model? Anyone have some data on seting the pressure between the two regulators?
Set it at 30 psi ( 2 bar) 8) The regulator is adjustable from 28 psi to 32 psi and if you can't achieve this,replace. Good luck
Last edited by Nutz on Sat 31 Dec, 2005 6:56 am, edited 1 time in total.
User avatar
OzBenzHead
300 SLR
Posts: 2140
Joined: Mon 22 Aug, 2005 9:11 am
Model you own: w126
Region: New South Wales
Location: NSW Central West

Post by OzBenzHead »

G'day, Nutz! :)

Good to "see" you over here! Long way from Alaska! :lol:
OzBenzHead
Currently:
1983 C126 500 SECBruno
2003 BA Falcon ute 4.0L Barra 182Henry
Formerly:
1955 W180 220a – Ponty
1964 W112 300 SE/C – Béla
1965 W111 220 S – Hektor the Heckflosse
1970 W108 280 SE – my first Benz – Karl
1973 W116 280 SE Crayford Estate – der Rolfwagen
1975 W116 450 SE – Goldy Horn a.k.a. Thirsty Merc
1980 W116 280 SE – Boris
1989 W124 300 E – Hester
1992 W201 180 E – Babe I
1992 W201 190 E 2.0 – Babe II
+ numerous W108/116 rolling spares
Prior to my M-B epiphany:
53 cars including many British oil-leakers (e.g. 14 P4 / P5 Rovers!), frequently cursed by Lucas the Prince of Darkness. Learnt to drive grey Fergie tractor and '27 Nash paddock-basher ute aged 8. First car owned (age 13): 1953 Fiat 500.
User avatar
Nutz
E Class
Posts: 74
Joined: Fri 30 Dec, 2005 8:44 pm
Model you own: w116
Location: Hawaii [ Maui ]

Post by Nutz »

OzBenzHead wrote:G'day, Nutz! :)

Good to "see" you over here! Long way from Alaska! :lol:
Thanks for the welcome 8) Lurking was sort of boring :lol:
User avatar
ADow
C 111
Posts: 854
Joined: Tue 21 Jun, 2005 4:25 pm
Model you own: w108
Location: Gilberton, Adelaide, SA
Contact:

Post by ADow »

Great collection - how do you keep them out of the weather?
Alastair
1971 280SE 3.5 - Don Ottavio - sold
1980 300D (formerly daughter's) - Heidi - sold
1999 C200 Elegance (currently daughter's)
1981 300D (son's) - Hektor (departed)
1998 Puma Clubman with 250 RWKW SR20DET - Percy
2011 VW Tiguan
2007 Jeep Cherokee
http://www.youtube.com/user/adow77
User avatar
Nutz
E Class
Posts: 74
Joined: Fri 30 Dec, 2005 8:44 pm
Model you own: w116
Location: Hawaii [ Maui ]

Post by Nutz »

ADow wrote:Great collection - how do you keep them out of the weather?

3 of my W116's are stuffed in my garage,the rest except my 6.9 (heated storage)are dealing with the elements.
User avatar
1973_280E
A Class
Posts: 13
Joined: Wed 27 Jul, 2005 3:57 pm
Model you own: w114
Location: Brisbane, QLD

Post by 1973_280E »

Thanks for the tips guys. I'll have to take it in to my mechanic again as I don't have the appropriate tools for checking the pressure.

Further to my previous explanation on the symptoms, the fuel pressure seems fine on starup. It's only once the engine has warmed up that the idle gets 'bumpy' and it starts to die on me.

Nutz, I assume the regulator pressure you mentioned refers to the one leading into the engine. Any ideas on what the one coming out of the engine is for (on the fuel return line, lower in the engine bay)? And what the effects of adjustments to this are?
User avatar
Nutz
E Class
Posts: 74
Joined: Fri 30 Dec, 2005 8:44 pm
Model you own: w116
Location: Hawaii [ Maui ]

Post by Nutz »

1973_280E wrote:
Nutz, I assume the regulator pressure you mentioned refers to the one leading into the engine. Any ideas on what the one coming out of the engine is for (on the fuel return line, lower in the engine bay)? And what the effects of adjustments to this are?

Do you have a photo of the area on your M110? I haven't seen a D Jet setup on a M110 yet.Going by the setup on my M117's,the feed line goes to the first regulator then to the second one.I have no regulator on the return line,so I'm a bit confused :lol:
User avatar
1973_280E
A Class
Posts: 13
Joined: Wed 27 Jul, 2005 3:57 pm
Model you own: w114
Location: Brisbane, QLD

Post by 1973_280E »

I'll have a look around for photos and get back to you. I took many photos during the engine dismantling stage. :wink: I'm sure I've got a clear pic of it somewhere.
User avatar
1973_280E
A Class
Posts: 13
Joined: Wed 27 Jul, 2005 3:57 pm
Model you own: w114
Location: Brisbane, QLD

Post by 1973_280E »

I managed to find a decent photo of the fuel setup. The green arrows show the fuel lines coming in and the red ones show the fuel exiting to the return line.

Image

I can't find this setup in either the w114 or the w116 manuals :(
User avatar
O319-coach
Mercedes Guru/Admin
Posts: 456
Joined: Mon 20 Jun, 2005 5:29 pm
Model you own: w124
Region: New South Wales
Location: Canberra
Contact:

Post by O319-coach »

Top one is the fuel regulator. Lower one is a damper.

You check the pressure by taking the line of the cold start injector and testing with the engine running.
Kind regards, / Mit freundlichen Grüßen,

John Green Member Institute Automotive Mechanical Engineers

www.mbspares.com.au Ph (02) 6239 1099
User avatar
1973_280E
A Class
Posts: 13
Joined: Wed 27 Jul, 2005 3:57 pm
Model you own: w114
Location: Brisbane, QLD

Post by 1973_280E »

Thanks O319-coach. As Nutz kindly mentioned, the fuel regulator should be set at 30psi. Just for clarification, does the damper require some tweaking for setting the pressure as well? If so, what are the settings for the damper?
User avatar
O319-coach
Mercedes Guru/Admin
Posts: 456
Joined: Mon 20 Jun, 2005 5:29 pm
Model you own: w124
Region: New South Wales
Location: Canberra
Contact:

Post by O319-coach »

30psi?? Are you working on an English car? Adjust to 2.0 bar.

The fuel damper is not adjustable.
Kind regards, / Mit freundlichen Grüßen,

John Green Member Institute Automotive Mechanical Engineers

www.mbspares.com.au Ph (02) 6239 1099
User avatar
1973_280E
A Class
Posts: 13
Joined: Wed 27 Jul, 2005 3:57 pm
Model you own: w114
Location: Brisbane, QLD

Post by 1973_280E »

Thanks John. 8)
Post Reply