Mercedes-Benz Forum banner

1 - 11 of 11 Posts

·
Registered
89 300e
Joined
·
4 Posts
Discussion Starter #1
Hi, i have a 89 300e, its been sitting for a year while i underwent cancer treatment. Now I am fine but the benz wont start. There seems to be good fuel pressure into the fuel distributor. I do not have a gauge, but can not stop it with my finger, but there is very little pressure at the injector. Gas flows out but with almost no pressure. When i take the cold start injector tube off, there is lots of pressure there.
Any thoughts???
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,744 Posts
Remove the injectors and have them cleaned. If you have a compressed air source, fill one end of the injector and then hit it with air. Or, soak the injectors in carb cleaner for a day. Remove and blow them out with the compressed air.

Glad you are back on your feet. Last year I went through 658 hrs. of chemo therapy so I know where you are coming from.

Good Luck, welcome to the forum and please take a few minutes to complete your profile. It allows us all to be of more help to you.

Jayare
 

·
Registered
89 300e
Joined
·
4 Posts
Discussion Starter #3
Thanks for the info, i might have to do that, but i am talking about the feeds to the injectors not having pressure. I am afraid the fuel distributor is clogged up.
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,744 Posts
Fuel will not exit the distributor unless the air plate is slightly depressed. It is connected to a plunger pin on the bottom of the fuel distributor. Plate goes down, pin goes up to release fuel.

Good Luck and thanks for completing your profile.

Jayare
 

·
Registered
2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
Joined
·
5,445 Posts
I recommend pulling the lines off each injector and putting a cup under each. (which I am guessing is what you did minus the cup...) start the fuel pump pump and depress the airflow plate and measure the total quantities of fuel between each.

Manual states:
http://www.w124-zone.com/downloads/MB CD/W124/w124CD1/Program/Engine/103/07.3-1609.pdf

idle : 4cm^3 /min
part load: 30cm^3 /min
WOT: 100cm^3 /min

max difference tolerated:
part load: 4cm^3 /min
WOT: 10cm^3 /min

If you don't get those values, FD is clogged or the little valves are stuck.

Before "replacing" it though. Try letting it soak in carb cleaner for a day like you would with injectors. It is worth a shot....FD's are too expensive not to attempt this.
 

·
Registered
89 300e
Joined
·
4 Posts
Discussion Starter #6
Thanks for the info, i tried the test on #1, in 10 secs got less than 8ml at wide open, thats about half the flow. And the gas seemed to dribble out, not come out with any force. Then the third time i tried, nothing. The cold start injector flows like crazy.

Can i take the "dosificador" as we call it here, or distributor off with just the three screws in the top??? Is there anyway to save the o-ring for the time being(just for testing), i live days away from parts.
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,744 Posts
By chance have you checked that both fuel pumps are in order? Fuel filter new? There are no servicable parts inside the fuel distributor, unless you are in the business of re-manufacturing them.

Jayare
 

·
Registered
2008 E350 4M, 2016 Audi Allroad, 2019 Audi Q5
Joined
·
5,445 Posts
Ok so you have confirmed a restriction -- now confirm if it is fuel pump related or distributor related.

Look at testing the fuel pump first to rule it off:
http://www.w124-zone.com/downloads/MB CD/W124/w124CD1/Program/Engine/103/07.3-5701.pdf

The fuel distributor can be serviced, although it can be difficult. There are a number of O rings that can be replaced. I am yet to do it myself, but plan to in the next month or so when I head to the junkyard and pull one to use as a test dummy.

---

Yes you can remove it. Just disconnect all the fuel lines, unscrew the three bolts and remove carefully. More than likely the O-ring underneath will stick to the bottom due to age. Just let it soak in boiling water so it can become soft again if you must re-use it.
 

·
Premium Member
'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
Joined
·
10,378 Posts
Old trick I learned yrs ago; find some brake cleaner with Tetrachloroethane or find some carbon tetrachloride. Soak O-rings, rubber/neoprene seals etc for exactly ten minutes and remove. Providing there are no cracks or visible deformities, this will restore them to almost like new condition. Some of the green colored gas rated O-rings will require more time because they are Buna-N (Nitrile)....tough stuff.

I got in a horrible argument once with a chemist about Tetrachloroethanes and Trichloroethanes. They even have sub numbers to identify slight differences and slightly different spellings. That's why I say stick with brake cleaner with Tetrachloroethane because I know it works. There are even more seal tricks you can do with this stuff but hey, I gotta have some secrets.:thumbsup:

Kevin
 

·
Registered
89 300e
Joined
·
4 Posts
Discussion Starter #10
Found the problem

Thanks for all your help, after fighting for a day to remove one of the nuts on the cover over the pumps and filter, got them of and found the filter clogged, and one pump bad. Then i tried to drain the fuel tank took over a day to drain out about 8 gallons. So pulled the tank and found an inch or more of rusty sludge in the bottom of the tank. So I am cleaning the tank and looking for the money for two new pumps. Down here in Costa Rica they are about $150 each for bosch pumps

thanks again
 

·
Premium Member
'92 300TE 4matic 280,000miles, '92 300TE 4Matic 'Ice Blue Metalic' 101,000miles
Joined
·
10,378 Posts
Must be a combination of lousy gas and climatic conditions. I would assume that your fuel accumulator is bad as well-so replace that too.:thumbsup:

Kevin
 
1 - 11 of 11 Posts
Top