Fuel line blockage - PeachParts Mercedes-Benz Forum

gtwendt · #1 06-20-2009, 07:14 AM

I recently changed out the fuel filter and fuel pump on my 1976 450SL. I noticed that the fuel line between the fuel and the pump was blocked at one of the connections. How in the world was the engine getting any fuel at all? The car has ran very sluggish and would backfire through the throttle plate. Could this have been the cause? I haven't fired it up yet since the change out due to other issues that I'm working on. Thanks for any and all input on this.

ctaylor738 · #2 06-21-2009, 05:20 PM

You didn't say where the blockage was, but it doesn't take much fuel to keep the engine running and idle and low load, so the pump was probably able to push a bare amount through with enough pressure to open the injectors. The symptoms you described are those of insufficient fuel volume, so you should be pleased with the results of your repair.

gtwendt · #3 06-22-2009, 04:24 PM

The blockage was at the connection to the fuel filter. After installing the new pump and filter, I can't say that the car runs any better. It still backfires through the throttle plate and runs sluggish. Any ideas?

nobby · #4 06-23-2009, 04:13 AM

Quote:

Originally Posted by gtwendt

The blockage was at the connection to the fuel filter. After installing the new pump and filter, I can't say that the car runs any better. It still backfires through the throttle plate and runs sluggish. Any ideas?

What kind of blockage? Dirt and debris?
If so, maybe the in tank fuel screen is "blocked" as well.