momentart miss and shut down fuel odor - PeachParts Mercedes-Benz Forum

NEAL560SL · #1 03-31-2006, 08:44 AM

I have a 1986 560SL with 36,000 miles, new spark plugs and ignition cables. When starting after having been run and sitting for a half hour or more, it will miss on a couple of cylinders for about 5 to 15 seconds then smooth right out and run perfectly until the next time. Yesturday I started it for the first time since last fall and it started right up and never missed a beat. It sat all day at work and when starting it after sitting all day, the usual miss then smooth. When I got home last night I parked it in the garage, then came back into the garage an hour later I was aware of a fairly strong gas odor. I looked under the car everywhere and could find no leaks, nor did it seem stronger smelling in any particular spot. This morning I thought I would drive it to work again and the same miss when started but only for a few seconds. I feel the odor and the miss are probably connected, but don't want to start trowing parts at it. Anyone with any ideas?

Thanks

kbannister · #2 03-31-2006, 10:04 PM

I read on one of the forums somewhere the miss at start up could be leaking injectors. It is an easy fix and not costly to replace the seals. I would start there. Don't know what to tell you about the odor

NEAL560SL · #3 04-03-2006, 07:56 AM

Thank you for the reply. That was my thought also, but when you talk about seals, don't you still have to replace the entire injector? I wondered if the gas odor could also be from the injectors leaking into the intake causing the odor from air intake area. The cheapest I've found them is around $50 each online.

kbannister · #4 04-03-2006, 12:12 PM

I would suspect the gas odor could be related to the seals also. I don't know why you would need to replace the injectors unless they are clogged beyond cleaning or really worn. I wouldn't think with the low miles they are worn, just the victim of aged seals. I sometimes have the same problem with my 500Sl. Seem to be worse in colder weather.

ctaylor738 · #5 04-03-2006, 03:18 PM

The missing at startup is probably a weak injector. The gas smell is probably something malfunctioning in the tank ventilation system.

GSMITH · #6 04-08-2006, 10:46 AM

Check the vent line on the fuel pressure regulator that is located on the driver side. The plastic vent line should run to the rubber vent hose that connects to the rear passenger side valve cover. If the diaphram goes bad it leaks gas into the crankcase and the fuel odor will be hard trace down.

If this is the problem change your oil as the gas will thin it out.

Let us know how you fixed this.

Gary