87 300d stutters in the passing gear - PeachParts Mercedes-Benz Forum

777funk · #1 06-19-2007, 09:40 AM

I have a 603 turbo that when I floor it up a hill begins to take off like a rocket then starts to stutter sort of rythmically. Any ideas?

I noticed the EGR vacuum hose is off of the EGR. Could that be a problem?

babymog · #2 06-19-2007, 10:30 AM

EGR only works at part-throttle, not at idle or full-throttle.

Could be the fuel filter, that'd be my first check.

If it's shuddering with the engine pulling strong it could be a slipping clutch in the trans.

777funk · #3 06-19-2007, 10:50 AM

It's definitely an engine issue. It's almost as if it had a govenor. The fuel filters are new so I don't think that's it.

777funk · #4 06-19-2007, 10:51 AM

Oh... and the EGR is unplugged (the vac line is missing).

777funk · #5 06-19-2007, 11:26 AM

Someone just PM'd me that the tank screen may be plugged. I'll check that out. That sounds likely to me. I just changed the two fuel filters why didn't I think to clean the tank screen. I'll be checking that right away tonight.

777funk · #6 06-19-2007, 11:33 AM

Also,
Anyone know what all the vacuum lines under the air cleaner box are??? I see one line that goes to something by the turbo (under the EGR) and a whole gob of lines under the air cleaner. One has a filter that looks like a fuel filter. What is all of this mess???
Thanks,
Nick

babymog · #7 06-19-2007, 01:58 PM

Try it with the fuel cap off too, might be a clogged vent.

The two vacuum devices control the EGR, and the wastegate. You don't need the EGR IMO, plug that line back in with a BB in the rubber hose is the preferred way to disable it, the wastegate (lower hose on the turbo) is necessary.

Bio300TDTdriver · #8 06-19-2007, 02:02 PM

Quote:

Originally Posted by 777funk

Also,
Anyone know what all the vacuum lines under the air cleaner box are??? I see one line that goes to something by the turbo (under the EGR) and a whole gob of lines under the air cleaner. One has a filter that looks like a fuel filter. What is all of this mess???
Thanks,
Nick

Do a search for EGR. That junk is all related to it. You can get a kit and remove the EGR for "testing" purposes, along with the junk.

Chris

777funk · #9 06-19-2007, 03:28 PM

I drained the Fuel tank and it flowed out very quickly. This leads me to believe the fuel tank strainer is not plugged. Now I have NO idea why the engine hesitates at speeds over 50 or 60mph when I floor it.

Brian Carlton · #10 06-19-2007, 04:51 PM

Quote:

Originally Posted by 777funk

Also,
Anyone know what all the vacuum lines under the air cleaner box are??? I see one line that goes to something by the turbo (under the EGR) and a whole gob of lines under the air cleaner. One has a filter that looks like a fuel filter. What is all of this mess???
Thanks,
Nick

You'll find a four way connector at the outlet of the vacuum pump. Two of those lines head over to the right side of the vehicle behind the headlight. You can remove those two lines and every single device that you find downstream of those two lines.

M/B makes a nice "F" connector to replace the four way connector and have a perfect underhood look. I can probably dig up the p/n if you want it.

777funk · #11 06-19-2007, 05:08 PM

I just talked to the nearest Mercedes dealership. The diesel tech said that the EGR could cause such a problem. I'll have to try blocking that when I get time.

777funk · #12 06-19-2007, 05:33 PM

Brian, what advantage would those two lines removed have on the car's performance. I don't know what they do so I thought I'd ask.
Thanks!
Nick

Quote:

Originally Posted by Brian Carlton

You'll find a four way connector at the outlet of the vacuum pump. Two of those lines head over to the right side of the vehicle behind the headlight. You can remove those two lines and every single device that you find downstream of those two lines.

M/B makes a nice "F" connector to replace the four way connector and have a perfect underhood look. I can probably dig up the p/n if you want it.

bobman006 · #13 06-19-2007, 06:00 PM

Quote:

Originally Posted by 777funk

I drained the Fuel tank and it flowed out very quickly. This leads me to believe the fuel tank strainer is not plugged. Now I have NO idea why the engine hesitates at speeds over 50 or 60mph when I floor it.

Did the fuel pour out of the tank strainer itself? The send and return lines on your car are almost level with each other on the '87, last time I looked back there. You can also swap the send and return lines to back flush the tank strainer instead of pulling it to clean it. Also, don't discount your fuel filters just because they are "new", especially if you are running WVO.

I have replaced my fuel filters, primary and secondary (mostly primary), more times than I can count since I started blending WVO in with my diesel at low concentrations: 20-40%WVO 80-60% Diesel. I still have an algae problem! I need to get some StarTron!

Anyway, filters are cheap, replace and see how it goes. It really sounds like a secondary filter plug to me.

Bio300TDTdriver · #14 06-19-2007, 07:09 PM

Quote:

Originally Posted by Brian Carlton

You'll find a four way connector at the outlet of the vacuum pump. Two of those lines head over to the right side of the vehicle behind the headlight. You can remove those two lines and every single device that you find downstream of those two lines.

M/B makes a nice "F" connector to replace the four way connector and have a perfect underhood look. I can probably dig up the p/n if you want it.

601-078-06-45 I bought one so when I put the kit on I could get rid of the solenoids as well as the EGR.

Chris