'88 300E Starving for Fuel

This morning I got a mile or so from the house and seemed to be losing power, when I started lifting the throttle, it found a point where it wanted to make power again. When I pressed down again, it would lose power again. It then smoothed out for a little while then started it again.

It felt exactly like a carbureted car with a clogging fuel filter. I finally turned around and headed home after about 8 miles out. I made it back at about 45 MPH. If I gave it too much throttle, it stumbled and lost power.

Do you think this is simply a clogged fuel filter or could it be the fuel pump not making enough pressure?

Everything electrical seemed fine, I don't think the OVP relay is the problem.

Any thoughts?

BTW, I got back home and got out the C Class, it had a flat tire. I guess this is my day to pay the car Gods.

Have a great day,

[Mike Richards]

Larry:

You know alot more about MBs than I do, so I sort of feel silly responding.

Your situation does mimick that of a carb-engine with a plugged rear fuel filter. Have seen Acoords do this more than once. MB maint manual indicates 60K service for that beer-can fuel filter your 103 motor has. I personally think that's too long. I never let mine go more than 20-25K. How long has your's been on?

If it's been awhile, I'd back your 300E up on some ramps for easier access and remove/replace the filter for starters. OEM Mann/Bosch units are around $25. Dealers prices on these things more than doubled about a year ago.

Regards.

Mike,

Thanks for the response. I feel that a fuel filter will fix it up. I try to replace it about every 30 or 40k miles, but I drive so much it can get away from me. I did not have time this morning to check the logbook to see when it was changed.

More important than when it was changed is; am I getting nasty fuel. I started buying fuel at a Phillips station on my beaten path after 9/11. The reason for my change is that Phillips uses no crude from the middle east. The station is relatively new, but they may have some junk in their tanks. Or, I often get fuel at 4:00 AM by paying at the pump. It could be that the truck comes there at 3:30AM and stirs up the junk in the tank.

I'm going to get a filter today and stick it on tonight. I feel pretty confident that will cure the problem.

Thanks again for the response,

[ctaylor738]

Clearly, the algae from your diesels has mutated and is now attacking gasoline.

But semi-seriously, I would start from the tank and work forward to see if or where you are losing pressure. My book does show a strainer in the fuel tank.

Good luck.

[robi99]

Larry,
Please post a follow-up to let us know if the filter did the trick. I had an identical problem a couple of years ago on a busy interstate, 200 miles from home. I thought I was going to have to stop but "Da Benz" kept going and improved enough to get me home. I replaced the filter the very next day and the problem seemed to go away however, a few days later, I experienced a minor version of the same problem and long story short, continue to have it happen occasionally. It typically happens right after start up on initial acceleration and it goes away. Rarely it happens at highway speeds, lasts for awhile and goes away. Maybe I have a lot of junk and the new filter was polluted after just a few days??
Let us know
Thanks

Will do, however, I leave for Switzerland on Saturday and will be gone over a week. Hang on 'til I get back.

Have a great day,

[csnow]

Robi99,
Those were the same symptoms I had prior to my fuel pump failure. More intermittent than Larry's problem.
Surprising is this would go 2 years without escalating, however.

I was not able to remove the filter screen at the bottom of the tank for cleaning- corroded in place for good! I imagine the screen (if fouled) could cause this, or Larry's problem as well.

There is also that pressure balancing device next to the filter and the pump. This could certainly cause Larry's symptoms, though I'm not sure if it could cause intermittent problems. Not sure if these are prone to failure...

I put a fuel filter in last night and drove about five miles. It ran fine. There may be more problems in store as some of you have experienced, but everything's good for now.

Thanks for the responses,