Oh Boy-Something was bound to start acting up- - PeachParts Mercedes-Benz Forum

Tims450SL · #1 07-10-2009, 08:25 AM

Hey folks- My first issue is coming up with my 1985 380SL with 85K miles...Two days in a row- I have started her up in the morning (here in Florida-at least 75-80 degrees outside) and for the brief couple of seconds i get no RPMS like giving her gas--- Is this a sign of the fuel pump giving out or a need for a fuel filter- after that little hesitation not probs all day and nite...your thoughts are greatly appreciated as always!! Thanks~~

dugald · #2 07-10-2009, 08:49 AM

I don't understand your problem. What happens?

MattBelliveau · #3 07-10-2009, 09:12 AM

You mean like for the first few seconds after you start it, it kind of stumbles and chokes, kind of like its not getting enough fuel? Does this only happen the first start of the day (cold engine)? How does it run after it warms up? How does it start once it warms up?

Tims450SL · #4 07-10-2009, 10:10 PM

yes it is a little stumbly- like water in the gas- maybe I got some bad gas- but then it is perfect runs a little different though...I have noticed the idle is up to 900-1000 without AC on. all of a sudden out of the blue this started. Could it be the cold start injector? Do they get stuck? there is a vacume hose missing from the front of what i think is the fuel distribitor on the top where the line goes out...gona take a pic in the am... but it is only for a minute when the car is cold from start. i think she is wasting more fuel than normal also.

meltedpanda · #5 07-11-2009, 08:04 AM

do you smell fuel at start up or after sitting?

Tims450SL · #6 07-11-2009, 03:03 PM

no fuel smells at all-

meltedpanda · #7 07-11-2009, 05:40 PM

do you hear the fuel pump spin up?. Leaking cold start would make for hard starting as would leaking injectiors , with puff of black smoke on start

Tims450SL · #8 07-12-2009, 02:24 PM

ron- there is no leak or fuel whine- yesterday I was determined to get to the bottom of the issue. I took off the aircleaner- check the filter (new) and the secondary filter at the edge(new) the front left side rear vaccume hse was not connected to the air cleaner.I checked all vac lines that I could. There is one on the small rectangluar unit that has 3 or 4 metal fuel lines coming out in the very front left where it looks like it is a sqaure little box-but one vac line that is not there. I disconnected the vac line next to the distributor and it droped to a significant reduction- puttinit on and off the round deal (Vaccume adjustment deal) it would like almost snap-high low high low...I then noticed the idle was perfect when I have the AC unit on (at 700) without it is at 1000- I guess maybe I never noticed this before- maybe it was adjusted higher to make sure the engine would not die during the idle with the AC on- any thoughts?? Thanks !

meltedpanda · #9 07-12-2009, 03:43 PM

your idle should advance with AC on , but a 1000 without it on is just a tad high. I sent you some info to your email, remember these units are vasuum dependent , missing lines should be rectified. The only acceptable line off is the conenction to the termal sensor on the air intake and I am not sure yours has it.

Tims450SL · #10 07-12-2009, 09:36 PM

ill study it -thank you..

slfan · #11 07-12-2009, 11:54 PM

The rectangular box you describe could be the Warm Up Regulator. This "box" has a vacuum like curved tube on the top which is supposed to be open. It measures atmospheric pressure, if I am not mistaken. On the sides near the bottom are two vacuum hoses which are not supposed to be open.