99' E300 fuel delivery problem and computer problem - PeachParts Mercedes-Benz Forum

EdzBenz · #1 08-19-2008, 04:09 PM

I had the shut-off valve, applicable o-rings, and some fuel lines replaced on my car about 2 weeks ago. After about 500 miles of driving, I am now unable to get the car started. Here's what's happening and my steps to address the problem:
-Engine cranks and sputters, but does not turn over
-While cranking the engine, I notice a lot of air bubbles passing through the clear fuel lines
-I replaced my fuel pre-filter and my regular filter. Each filter was filled with fuel before replacement. Symptoms still occurred
-I put a vaccuum on the fuel pre-filter line. It did pull some fuel, but it pulled a ton of air. The air did not stop after 5 minutes of vaccuum.
-I disconnected the fuel supply line to my filter. After disconnection, I tried cranking the engine. I hoped that fuel would shoot out of the supply line. No fuel came out after multiple cranks.
-I gave up my personal quest and took it to the mechanic
-My mechanic has been trying to diagnose the problem, but has now encountered two more problems: 1. The starter is now dead. 2. The engine computer diagnostic system is not being recognized.

Anyone have any ideas?

TMAllison · #2 08-19-2008, 04:19 PM

Sounds like you may have forgotten to install the oring beneath the pre-filter when you replaced it? Wouldn't be the first time it was inadvertently thrown out.

Air leaks wont create a code.

EdzBenz · #3 08-19-2008, 04:31 PM

Terry,
That is a good idea. I'll definitely check that, although i'm quite sure I put the o-ring in there.
This problem was happening even before I replaced the fuel filters though.

TMAllison · #4 08-19-2008, 04:52 PM

What about the oring behind the SOV?

Did you put a new oring on the main filter bolt? Overtighten maybe?

Sounds like you need to start with the basics and find the point of entry. The fuel path (am doing this from memory) starts at the prefilter, then out the bottom of the prefilter to the SOV, from SOV over to lift pump, out lift pump up to main filter, out main filter back to SOV and then into IP.

Start at the beginning of the fuel path and find the first line with air in it. The leak precedes that point.

EdzBenz · #5 08-21-2008, 03:57 PM

Update: I spoke with the mechanic today. He said that as far as he can tell, that its the SAMS computer which has failed. Total=$300 for the repair.

TMAllison · #6 08-21-2008, 04:26 PM

Your first post says you have bubbles present when attempting to start.

Although possibly bad, a computer is not going to fix an air leak.

It is usually best to fix leaks on the 606 first, and then troubleshoot whats left next. Oftentimes once leaks are fixed other issues disappear.

nhdoc · #7 08-22-2008, 09:21 AM

Quote:

Originally Posted by TMAllison

Your first post says you have bubbles present when attempting to start.

Although possibly bad, a computer is not going to fix an air leak.

It is usually best to fix leaks on the 606 first, and then troubleshoot whats left next. Oftentimes once leaks are fixed other issues disappear.

X2. Terry is absolutely right. 99% sure your problem is the pre-filter o-ring not something electronic. Your mechanic is incorrect so find someone else or fix it yourself for $1 and in 5 minutes. I bet you had a problem the first time you tried to start it with a low level of fuel in the tank or the nose was pointing up? Those are classic symptoms of leaks in the fuel system.

EdzBenz · #8 08-22-2008, 12:35 PM

Oh crap. The car is supposed to be ready today. I'll talk to the mechanic. Thank you for the suggestions.

Mike-In-Sky · #9 02-13-2010, 08:33 PM

Quote:

Originally Posted by nhdoc

X2. Terry is absolutely right. 99% sure your problem is the pre-filter o-ring not something electronic. Your mechanic is incorrect so find someone else or fix it yourself for $1 and in 5 minutes. I bet you had a problem the first time you tried to start it with a low level of fuel in the tank or the nose was pointing up? Those are classic symptoms of leaks in the fuel system.

I am so glad I read this. After my wife and I both had problems starting our 99 E300TD. The common denominators were, we both had low fuel and parked with the nose high. I thought someone would laugh at me if I suggested that the nose being higher than the rear may have something to do with our problem. I have parked the car in my garage for over a week now. (scared to drive it. In fear of it not starting on the road). Since parking it, It has started easily every time. At least once every morning and evening. I have been reading a lot of threads on this forum since parking it. This has helped me realize it is a fuel problem. I was going to order a Viton o-ring kit from www.fryerpower.com. A delivery valve removal tool, delivery valve copper seals and o-rings from www.*********.com, crush washers and o-ring for the banjo bolt, (overflow valve), a shutoff valve o-ring, and new fuel lines. Then I was going to remove the IM and go to work. I just walked into the garage after reading this post and found that the top of the prefilter is cracked into two pieces and a little loose. Can it be that simple? I will find out as soon as I locate a new prefilter and replace it and the fuel filter. Hopefully that will get us back on the road. I will keep you posted.

There are some great folks on this forum. With their help I was able to replace all of my glow plugs and injector nozzles. What a big difference that made.

notfarnow · #10 02-14-2010, 01:35 PM

Quote:

Originally Posted by Mike-In-Sky

This has helped me realize it is a fuel problem. I was going to order a Viton o-ring kit from www.fryerpower.com. A delivery valve removal tool, delivery valve copper seals and o-rings from www.*********.com, crush washers and o-ring for the banjo bolt, (overflow valve), a shutoff valve o-ring, and new fuel lines. Then I was going to remove the IM and go to work.

You can change the o-rings and lines without removing the IM. Take out the window washer jug, and the fuel filter housing. That gives you full access to the fuel lines. (but not the delivery valves)

nhdoc · #11 02-15-2010, 07:26 AM

Quote:

Originally Posted by Mike-In-Sky

...Then I was going to remove the IM and go to work. I just walked into the garage after reading this post and found that the top of the prefilter is cracked into two pieces and a little loose. Can it be that simple?...

Yes, absolutely, positively. That seal is critical to keeping the fuel system primed. Understand that the fuel (lift) pump on these cars is under the hood and it is imperative that every joint between the pickup and the pump be perfect or else the pump will lose its prime and will not pump fuel. Downstream of the lift pump those failures will result in a leak (the fuel is under positive pressure after the pump), so look for leaks downstream of the lift pump but upstream leaks will cause air infiltration only and normally you won't see an external leak from one of those joints. Fix your prefilter housing failure and your no-start conditions will go away.

Finally, you only need to replace the o-ring on the DV seals if they are leaking so if the top of the IP is dry save that for another day. It is best to solve one problem at a time.

Mike-In-Sky · #12 02-15-2010, 08:52 AM

[QUOTE=TMAllison;1943113]Sounds like you may have forgotten to install the oring beneath the pre-filter when you replaced it? Wouldn't be the first time it was inadvertently thrown out.

I didn't know there was an O-ring beneath the prefilter. Is it attached to the filter? or does it sit inside the housing on the bottom? Now I must go and have a look see.

Mike-In-Sky · #13 02-15-2010, 09:39 AM

Quote:

Originally Posted by nhdoc

Finally, you only need to replace the o-ring on the DV seals if they are leaking so if the top of the IP is dry save that for another day. It is best to solve one problem at a time.

There are a couple of reasons I will remove the IM. First, it will make the job of replacing all of my O-rings and lines a piece of cake. Also, I want to replace the delivery valve O-rings while the IP is so easily accessed. And I will replace the O-ring and crush washers on the banjo bolt / overflow valve, and the shutoff valve O-ring. I took off the IM when I replaced my glow plugs and injector nozzles. I thought it was no big deal. It does help a lot to have a friend help putting it back on though. My buddy that helped me has the same car. He will be working side by side with me on this project also. Together we may someday open our own MB repair shop. Kidding! LOL! This forum is such a big help. Without it, I would have never dreamt of attempting these projects. After this problem is solved, I intend on replacing the wheel bearings on all four corners and brakes if needed. The car has 190K on it, and is starting to make a woo woo sound at the passenger side rear wheel when moving.

Mike-In-Sky · #14 02-15-2010, 09:51 AM

I cant seem to find the 2nd o-ring for the prefilter either in the fuel delivery scematic or listed in the Viton o-ring kit on the www.fryerpower.com site. Both only show #29 o-rng that goes on the prefilter. ???????????????????????????????????????????????????????

What's a boy to do?

TMAllison · #15 02-16-2010, 12:55 PM

#29 is the pre-filter oring. It fits up under the rim of the pre-filter before its installed. The only other oring is the one on the end of the fuel line that plugs onto the top of the prefilter.