Plugged fuel line ? Crappy Idle Shake Rattle & Roll

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Plugged fuel line ? Crappy Idle Shake Rattle & Roll

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Mercedes Forum >> Mercedes Benz Models >> Diesel Discussions >> Plugged fuel line ? Crappy Idle Shake Rattle & Roll

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Plugged fuel line ? Crappy Idle Shake Rattle & Roll - 5/23/2008 6:53:11 PM

LT1_1993

Posts: 11
Joined: 4/16/2008
Status: offline

Hello , All ... I am trying figure out why my 84 300D Turbo w 317 000 runs strong just idle's like crap, Under 1000 rpms or so. I have searched the threads and found possisbly Rack Damper Screw is worn and weak , Motor Mounts and or Tranny Mount & Engine Shocks are most likely shot , The filters have been changed , Primary and Secondary and recently the Tank Screen which was squeaky clean
( probably due to the illegal WVO mix i ran ) The problem is when i disconected the fuel line from both sides and try to blow air through either side i am not able to . There is simply way to much resistance to flow at all using lung power . My question is .... Should there be be any resistance at all ? There is no check valve or somthing strange like that is there ? Possibly a pinched metal fuel line ? I am going to orchard to buy a nozzle for my 100 psi cheap compressor and force some air through there. Hope this does not hurt anything , Seems wierd that the Tank Screen would be clean yet the fuel line would be plugged . Any idea's will be appriated . Thank You MercedesForum

< Message edited by LT1_1993 -- 5/23/2008 6:58:25 PM >

Post #: 1

RE: Plugged fuel line ? Crappy Idle Shake Rattle & Roll - 5/23/2008 10:56:08 PM

LT1_1993

Posts: 11
Joined: 4/16/2008
Status: offline

Just got finished trying to blow through the metal fuel line . The air compressor i have is weak , I don't think it can blow 20 psi. No success going from the rear to the front . From the front to rear better somewhat better , by all means do i think it flows freely at all. When i blow compressed air ( 25 psi max ) from the rear metal line ... It will not blow through and all the pressure spitsback immediatly . I dont under stand how my car is able to draw fuel through so much resistance amazes me. Feels like there is a check valve or somthing, or the stock meatal fuel line is clogged or kinked . Do i need a much stronger compressor ? Yes my car idles smooth when i am disconected from the tank doing a Diesel Purge .{ with transmission fluid $ 1.26 @ walmart } Can't find Liqui Moly anywhere besides online. I know my car can idle smooth , as it does once i a while when it feels like it. Help... I know she starving for fuel sometimes because it will loose power and struggle to even run ... When i check the clear fuel filter it is nearly empty .... Let it sit for a minute and it will start and drive as usual only with very rough idle. Thank You for your patience.....

(in reply to LT1_1993)

Post #: 2

RE: Plugged fuel line ? Crappy Idle Shake Rattle & Roll - 5/27/2008 10:14:13 AM

paddo

Posts: 42
Joined: 12/20/2007
Status: offline

What I have done before, is put a piece of flexible tube on the engine end of the incoming line, and suck on it to see how the resistance is. Can get much more suction force with your mouth than blowing force. I found there is quite a bit of resistance but it comes through - you should be able to suck air at a steady slowish rate and soon fuel will appear. If not there's a block. If you are running diesel, I'd suggest using a fair length of clear plastic line you can get from hardwares, so you can avoid the fuel gettign in yoru mouth.
Mind you, getting old used VO in your mouth isn't exactly heaven either but I've done it a few times with no ill effects, with accompanying uncouth spitting into the street gutter.

(in reply to LT1_1993)

Post #: 3

RE: Plugged fuel line ? Crappy Idle Shake Rattle & Roll - 5/27/2008 4:46:40 PM

LT1_1993

Posts: 11
Joined: 4/16/2008
Status: offline

Ok im a idiot !!! Upon inspecting pictures from diesel giant . I found that my fuel lines somehow got switched . I dont know how it ran at all . Suprisingly it does not run to much different , a little more throtle response now. Rough idle is still there .... I know the filters are not blocked . Time to replace the Motor Mounts , Valve adjustment , Diesel Purge , Then the Rack Damper Screw. If it still idles rough i will replace or service the fuel injectors. Thank You for the sugestions.

(in reply to LT1_1993)

Post #: 4