380SL stalling problems at idle - PeachParts Mercedes-Benz Forum

rnelson · #1 09-04-2008, 12:46 PM

Hi everyone, I am in dire straights here and can not figure out this problem. I did a bunch of searches on this problem and started replacing things that I thought might be causing the problem.

I replaced the Fuel Pump Relay, Fuel Pump (loud whineing), and fuel filter. and before that I repleaced the fuel accumulator. I thought the problem was fixed and then all of a sudden it stalled again.

This is what happened last after the fuel pump/relay/filter replace. It was about 100 degrees outside, I drove it about 3 miles, I was stoped at a stop light, and the car just shut down. I pushed it off to the side of the road and about 10 minutes later is started back up. Compared to last time, before (fuel pump/relay/filter replace) it would not start back up for like an hour!

This last time when I got it to finally to start is was running a little rough, and when I would push on the gas pedal the car would barely move. So, that is where I am now.

This car is new to me and I want to start from the top. I have been doing numberous searches on this board and others. This was my brothers car and he had the stalling problem as well before he gave it to me. His mechanic did put a new fuel accumulator in the car just a few months ago and we thought the problem was fixed.

Basically, I would like to start to verify the vacum lines, timing, check the standard stuff like plug condition, rotor cap, etc...

Where should I start and more importantly where can I get a good cheap repair manual, which one do you guys recommend?

Any information on the vac lines?

Thanks for your help,

86560SEL · #2 09-04-2008, 07:11 PM

I had a 1985 380SE (same engine) that did the exact same thing, but it would always instantly restart. I took it to a MB mechanic and had it checked. He said my injector seals were leaking causing the stalling. They were apparently sucking in air, because there were no fuel leaks.

rnelson · #3 09-05-2008, 11:25 PM

Thanks for your advice, i will definitely check the seals this weekend. Does anyone else have any advice?

What about where to get a repair manual for the 380SL? Which one to get? Is there a specific one or are they all general?

86560SEL · #4 09-05-2008, 11:50 PM

Quote:

Originally Posted by rnelson

Thanks for your advice, i will definitely check the seals this weekend. Does anyone else have any advice?

What about where to get a repair manual for the 380SL? Which one to get? Is there a specific one or are they all general?

No problem. I am not sure how they went about checking mine, but he said that was the issue. Good luck!

pchmalibu · #5 09-06-2008, 01:01 PM

I'm not very technical but I do have that car with a similar issue. If you have a timing light I would hook it up the next time the car won't start to see if you are getting spark from the coil. If you are not the cause may be your ignition control unit or the green wire that runs from the unit to the distributor.

pchmalibu · #6 09-07-2008, 10:14 PM

i don't know if this is applicable but On another car I experienced similar issues because the +/- leads on the coil were loose.

Oracle12345 · #7 09-07-2008, 10:26 PM

Check for vacuum leaks. To see if your getting spark plug while running a ground it to metal. Also this test will identify what clyinders arent firing. When you pull a plug the motor behavior should change

rnelson · #8 09-11-2008, 08:43 PM

Okay you guys, here is a very frustrating update.
Just to recap...I have replaced the following:
Fuel Accumulator, Fuel Pump, Fuel Filter, Fuel Pump Relay, Just replaced the Ignition Control Unit, Distributor Cap, Rotor.
Okay, so since the last stall I started from the ground up. I checked the plugs (good), Dist. Cap was horrible, pitted and corroded as well as the rotor so I replaced those. When the car stalled on me the time before last it restarted fairly quickly after i messed with the Ignition Control Unit, So I found an aftermarket unit Hueco for $65 bucks so I decided since everyone was thinking this could be an issue I decided to just go ahead and replace this as well. Then I found some disconnected vac lines, I reconnected them. Finally, I checked and re-set the timing, per some instruction I found on here to 10 degrees BTDC, with vac line disconnected.
So, now here is the last stall. On the way to work this morning and hit shuts down in mid drive, I was going about 30mph in traffic and it was as if it just stop getting fuel and I coasted to a stop. I could not get it to start again. I tried for about 10 minutes and nothing. So the main difference here is that I was not at idle, I was driving.....
Now what? Where do I go from here? If it was a horse, I would shoot it!

86560SEL · #9 09-11-2008, 09:11 PM

Did you ever check the injector seals?

Quote:

Originally Posted by rnelson

Okay you guys, here is a very frustrating update.
Just to recap...I have replaced the following:
Fuel Accumulator, Fuel Pump, Fuel Filter, Fuel Pump Relay, Just replaced the Ignition Control Unit, Distributor Cap, Rotor.
Okay, so since the last stall I started from the ground up. I checked the plugs (good), Dist. Cap was horrible, pitted and corroded as well as the rotor so I replaced those. When the car stalled on me the time before last it restarted fairly quickly after i messed with the Ignition Control Unit, So I found an aftermarket unit Hueco for $65 bucks so I decided since everyone was thinking this could be an issue I decided to just go ahead and replace this as well. Then I found some disconnected vac lines, I reconnected them. Finally, I checked and re-set the timing, per some instruction I found on here to 10 degrees BTDC, with vac line disconnected.
So, now here is the last stall. On the way to work this morning and hit shuts down in mid drive, I was going about 30mph in traffic and it was as if it just stop getting fuel and I coasted to a stop. I could not get it to start again. I tried for about 10 minutes and nothing. So the main difference here is that I was not at idle, I was driving.....
Now what? Where do I go from here? If it was a horse, I would shoot it!

rnelson · #10 09-12-2008, 11:28 AM

I did not check out the injector seals yet because I found the other issues so I figure I would tackle those first. Plus if I am going to start to check them I should just replace them because they could be brittle, right? So, that is my next step. But look at what happened below last night.

Okay, so here is another thing to add. When I went to go pick it up last night it would not start at all so I swaped out the Ignition Control Unit with the old one and what do you know it started. Then I swaped it back, no go, then back to the old one and it started right back up! It seems that the brand new after market Hueco Ignition Control unit for only $64 sucks! I will have to call the place where I bought and see if they can get me another one.
Do any of you guys have any idea about this control unit? There is no way I want to spend the money for an OEM one.... I could always try the junk yard. What do you guys think?

pchmalibu · #11 09-13-2008, 11:21 PM

I went through 2 ignition controls from sun alley mercedes dismantlers that were no good

the tenor man · #12 09-14-2008, 06:03 PM

A number of years ago, my wife had a 1989 260E with similar symptoms. I found the problem...

It was the connection of the fuel pumps to the wiring harness under the rear seat. The connector had become badly corroded and the fuel pumps would work most of the time, but not always.

I removed the connector and soldered the wires...I never had the problem again....

Just a thought...
The Tenor Man

Lenny · #13 12-08-2009, 06:06 PM

I had a similar problem with my SL. It turned out to be the ICU (I bought an MB ICU - not cheap). This solved the problem. Does your engine hunt at idle (speed up and slow down drastically) and then die? Do you get erratic tach reading at idle and when you are on the road? The ICU provides the rpm signal for the fuel pump relay (fuel pump relay will shut down fuel pump with out this signal) and to the tach. The ICU is to the left of the radiator inside the engine compartment.

ctaylor738 · #14 12-08-2009, 10:49 PM

Check the screen in the gas tank outlet. Sounds to me like it is clogged and the engine runs out of gas. Then it sits for a while and will run.

popscat · #15 12-13-2009, 06:22 AM

aux air valve? spray carb cleaner on all your vacuum lines and around your injectors to see if you have a vac leak also check your over voltage relay or blown fuse for the ovp. replace your injector seals. also check your wiring harness in the truck as the wire for the fuel pump goes thru the tail lights also could be your cis. pressure reg on the fuel distributor. i had that go bad. also manuals i have a web site www. northernresource.com/ w107