engine starts and dies right away - PeachParts Mercedes-Benz Forum

blueshield11 · #1 02-29-2008, 01:01 PM

Now I have another problem with my 380SL 1982.

The engine only starts once, for about 2 seconds and then it stops. And no way it is going to start again, not even when I put some fuel spray in the "hole" of the air filter.
When I wait for a couple of hours the engine starts and stops right away.

I have checked the vacuum hoses and there is nothing wrong there.

When I loosen up 1 hose of the fuel distributor the fuel comes out.

I have checked the sparking plugs and they are dry.

It looks like when the car is standing for some hours the engine has become the fuel it needs to start but it dies right after that.

I hope you understand my english.

does somebody have any idea (s) ???

tecqboy · #2 02-29-2008, 02:24 PM

Plugged fuel filter?

pop & blow · #3 02-29-2008, 02:44 PM

Cup your hand over the carburator and use your hand as a choke and see if the car trys to stay running don't block off all the air to the carburator let it have a little air, if it will run with your hand over carb , then check you choke and see if it is working. sounds like a choke problem.

blueshield11 · #4 02-29-2008, 02:46 PM

Quote:

Originally Posted by pop & blow

Cup your hand over the carburator and use your hand as a choke and see if the car trys to stay running don't block off all the air to the carburator let it have a little air, if it will run with your hand over carb , then check you choke and see if it is working. sounds like a choke problem.

thanks for your reply, but this car has no carburator.

other ideas?

blueshield11 · #5 02-29-2008, 02:48 PM

Quote:

Originally Posted by tecqboy

Plugged fuel filter?

Thanks for your reply.

When I loosen 1 of the 2 hoses at the fuel distributor the fuel is coming out.

Do you mean that the amount of fuel is too little ?

aam · #6 02-29-2008, 06:29 PM

Your car has an idle speed control valve.
Turn the key on and off you should hear the valve click.
If not remove the valve, and see that it is open.
With key on ck to see that you have 12 volts on the connector.
If yes, take out the valve clean it with maf spray cleaner and try to free it up.
Do all that and come back.
Regards.
aam.

From your description the idle valve is stuck.
That's why you can start the car, and then it dies.

blueshield11 · #7 02-29-2008, 06:56 PM

OKay, thanks for your reaction.

Your answer gives me a slight problem to check if I can hear it click.
1. when I turn the key there is a loud noise for appr6-8 seconds. I don't know where that comes from (has nothing to do with the problem).
2. I do not know where the idle control unit valve is located. I have the description of my car from alldatadiy.com.

can you help?

blueshield11 · #8 02-29-2008, 08:58 PM

here i am again.

can somebody tell me how I can check if the air pump is funtioning ?

And can the air pump be exchanged with the air pump from a 450sl from 1975 ?

thank you

aam · #9 02-29-2008, 10:28 PM

Quote:

Originally Posted by blueshield11

OKay, thanks for your reaction.

Your answer gives me a slight problem to check if I can hear it click.
1. when I turn the key there is a loud noise for appr6-8 seconds. I don't know where that comes from (has nothing to do with the problem).
2. I do not know where the idle control unit valve is located. I have the description of my car from alldatadiy.com.

can you help?

First remove the air filter so you can see better.

The idle control valve is located in front of the fuel distributor
( The big round hole that air is going in to the engine)
It is silver collor about six inches long by one and half there two 3/4" hoses on it like a tee.
It has a two wire black connector on it.
If you going to do the job by yourself with out help.

1.Leave key on the on position, then go to the idle control valve disconnect
the connector / reconnect you should feel / hear a noise coming out of it.
The way this thing is working is like a chock on carburetors it makes the rpm go hi when cold 1400, 650 when hot.

So when your engine is running and you pull the plug out your rpm will go
to 1400 I don't know if this makes sense to you.
aam.

Ps. your car has fuel injection.
You can buy books from pep boys or somewhere ells.

By Chilton's or Haynes to help you with pictures.

Air pump fix it later.

Gurunutkins · #10 03-01-2008, 12:18 AM

HI Blueshield
your car should have CIS fuel injection. if it starts for a second and then cuts out and will not start I would look at your air flow sensor as well. remove the air filter and underneath is the fuel distributor and the air flow sensor. dont try and start the car or anything but just push down on the big flat plate blocking the air hole and note any resistance. then turn on the ignition just until the fuel pump (near the rear wheel of the car, will sound like a buzzing for a few seconds) turns on and then off (just a few seconds) then turn the ignition off and do the same test and note the resistance on the plate blocking the air hole. there should now be more resistance on the plate. if there is not you have a fuel pump or pressure regulator problem or at the least a fuel flow problem. if there is pressure (resistance) on the plate then just get a friend (standing away from the engine and just using their fingerrtips) to hold down the plate about 1mm and try and start the car and see if it idles.
cheers
Barri

blueshield11 · #11 03-01-2008, 03:05 AM

thank you for all your help.

I will see what I can do today with the car and get back to you with an update.

johncash · #12 03-01-2008, 10:51 AM

If it won't start even with starter fluid, I'd look at the electrics. I had a very similar problem and corrected it by installing a new contact section of the ignition switch. There are a lot of contactors here and all my problems disappeared. Runs perfect now.
I feel the weakest link for MB is the rounded domed worn contacts that they refused in re-design.

82gray380 · #13 03-01-2008, 02:14 PM

I agree with Johncash. I know everybody is trying to help you and thats what these forums are for, but as John stated, if it won't at least start for a couple of seconds with starting fluid. You more then likely do not have a fuel issue. There are electrical cut off sensors and ignition sensors. I think your at a point that you find a very reliable benz mechanic and have them hook into your computer system and see what they find. They might be able to determine the exact sensor or system that is faulty, instead of trial and error replacing parts. If it a decent shop, they will change you a small fee and let you fix it yourself if that's what you want. I also have a 82 380sl and have been chasing a rough idle issue for several months. I would have taken it in weeks ago, but my car runs great except at idle and it doesn't die out at stops, so I'll keep trying for a little longer, but I also have been told to get it check on a computer and I'm almost at that point.
Good luck

blueshield11 · #14 03-01-2008, 07:08 PM

I am grateful for all the help and answers here in this forum.

I have checked the idle control valve and I hear it by turning on the ignition. And I have also checked the throttle valve.

Considering the fact that I have opened 2 topics about my problems with this car I will tell here in short what has happened from the beginning.

At first the car was driving okay in the beginning (cold engine), now and then a plopping sound and another shrieking sound of which I thought I recognized as the sound of a bad generator or waterpump. That shreaking sound ended after a 10 minutes drive.

After I have driven for about 20 minutes or so I turned off the engine and then restarted the engine I observed the engine was not running smooth anymore. there was no power, just like 1 or 2 cylinders were not functioning.
The advice on this forum was that it could be the idle speed control unit. I have checked that and could not see anything special.

I have let the car running idle for half an hour and it ran smoothly. After that time the engine started to make a bad sound and stopped by itself.

From that time I cannot start the car anymore. Just 1 second on and then dies.

Could the shreaking sound I have heard in the beginning be from the injection pump? I am not sure, but maybe it is the injection pump that is the cause of my problems ? So when the engine was cold the injection pump functioned well and later when the engine was warm this pump was not functioning well.

I saw that one of the vacuum lines was loose from the throttle valve and therefor I have removed the complete fuel distributor and then put the vacuum line back in. But the engine still won't start.

So I have the idea, that it could be the injection pump, because I think I need that for vacuum which is needed to start the car ???

Can the injection pump be checked without a running engine ?

And where to begin to remove the injection pump ?

Quite a long story but it is to make you understand my problem better, I hope

THANKS !!

nobby · #15 03-01-2008, 11:01 PM

If you haven't been told yet, then let me be the first. Go get a manual for your car.
You have , what seems, from your descriptions, some serious issues and you are asking Mechanics 101 questions. You need to familiarize yourself with the basic workings of your SL before you have a hope of fixing it yourself.
Either that, or find a mechanic.

And don't drive your car if it is making unfamiliar and "bad" noises.