Mercedes-Benz Forum banner
1 - 20 of 29 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I have a 1990 300sl that I backed out of carport shut off for about 10 min tried to start turned over but no start. without shop manuals I'm lost can anyone help. Thanks Ralph
 

·
Registered
'96 SL 500
Joined
·
91 Posts
Sometimes if you start a car and turn it off quickly it can cause issues. Something to do with the fuel I think, maybe the engine gets flooded. Not much help now, but I like to keep a car idling until the start-up high idle stops and is replaced by standard idle speed.
 

·
Premium Member
'99 SL55 AMG & '00 CLK55 AMG
Joined
·
410 Posts
Try waiting a little longer.
 

·
Registered
'82 500sec euro, '95 Ford F150
Joined
·
1,765 Posts
The two replies are the about the dumbest replies I’ve read in a while. And I’m really not trying to be rude, or pick a fight. But come on.
For starters, we need a bit more info:
Manual or auto trans?
Does it just crank, but no start, or no crank at all?
Was the car operating flawlessly previously?
Did it actually start eventually?
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #5 ·
The two replies are the about the dumbest replies I’ve read in a while. And I’m really not trying to be rude, or pick a fight. But come on.
For starters, we need a bit more info:
Manual or auto trans?
Does it just crank, but no start, or no crank at all?
Was the car operating flawlessly previously?
Did it actually start eventually?
Thx its automatic it cranks but no start it was running great. no been 2 week won't start
 

·
Registered
300 CE 24V Sportline
Joined
·
1,471 Posts
Thx its automatic it cranks but no start it was running great.
I don't wish to depress you, but, I had similar during a misery period from July 2019 to June 2020. I blew 3 EZLs after installing new coil, cap, rotor, wires and plugs.

After the 3rd failure, we stripped out all the new stuff and re-installed new MB parts except the wires that are now the 12(?) year old Beru wires. The new Beru wires just would not click down nicely on to the plugs.

We also checked and cleaned all the earth connections we could.

And replaced the alternator and starter motor with Bosch reconditioned "new" units. This was prompted by a vague impression that these EZLs were being killed on start-up. Did I here it fire once before no-start? I really couldn't be sure.

And put a new MB Crank Position Sensor in, although these are very reliable and long-lasting.

It is now October 2021, 15+ months after the last dead EZL. Have I cured it? Maybe. But I cannot be 100% sure.

And, in all cases, the car was running like new before death.

I hope this is not your problem.

By the way, which engine, M103 or M104?

All the best.

RayH
 

·
Registered
2000 SL500, 2004 E320
Joined
·
865 Posts
The two replies are the about the dumbest replies I’ve read in a while. And I’m really not trying to be rude, or pick a fight. But come on.
I couldn’t agree more.

How about going through the basic steps (for diagnosing crank, no start)… spark, fuel delivery, compression… Any car, any (gasoline) engine, basics are the same.
 

·
Registered
'82 500sec euro, '95 Ford F150
Joined
·
1,765 Posts
I’d check the basic.
Are you getting spark or not. If you are, then you have a fuel related problem.

If that’s the case, you can jump pin 7 and 8 on your fuel pump base, once you pulled the fuel pump relay out. Be aware, that as soon as you jump those, the fuel pump should be energized, and pump fuel.
Now, if the car starts,most likely you have a bad fuel pump relay. HOWEVER, keep in mind that you have two fuel pumps. Even if one quits, it will sound as the “pumps” are on. The best practice is to remove the wires off each, one at a time and verify with the jumper wire. Obviously, the one not coming on with the jumper wire is the bad one. Once replaced, the car should start.

if you are not getting spark, I’d check the crank position sensor. Look for damage done by rats. The way they go bad is they usually quit when warm, but seems to be fine when cold.

EZLs can go bad.

Check the coil. Be sure you get +12v on the pod side of the coil with the ignition on.
 

·
Registered
1990 300sl
Joined
·
27 Posts
Definitely check for spark. It may be worth trying to read the blink codes for the MAS to see if there is a fuel pump issue. The MAS is where the fuel pump relay resides. I apologize but i don't recall which pin in the block is for the MAS. You can also pull the MAS and jump pins 1 and 2 to run the fuel pump without the relay.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #10 ·
I don't wish to depress you, but, I had similar during a misery period from July 2019 to June 2020. I blew 3 EZLs after installing new coil, cap, rotor, wires and plugs.

After the 3rd failure, we stripped out all the new stuff and re-installed new MB parts except the wires that are now the 12(?) year old Beru wires. The new Beru wires just would not click down nicely on to the plugs.

We also checked and cleaned all the earth connections we could.

And replaced the alternator and starter motor with Bosch reconditioned "new" units. This was prompted by a vague impression that these EZLs were being killed on start-up. Did I here it fire once before no-start? I really couldn't be sure.

And put a new MB Crank Position Sensor in, although these are very reliable and long-lasting.

It is now October 2021, 15+ months after the last dead EZL. Have I cured it? Maybe. But I cannot be 100% sure.

And, in all cases, the car was running like new before death.

I hope this is not your problem.

By the way, which engine, M103 or M104?

All the best.

RayH
sorry to sound stupid but what a ezl
 

·
Registered
300 CE 24V Sportline
Joined
·
1,471 Posts
what a ezl
It is the ignition control module. It looks like this:

Circuit component Audio equipment Electronic component Electronic engineering Auto part


They come in various flavours and prices, depending on the application? Complex ones as in this picture have 8 pins in those two sockets indicating knock sensors, and probably more.

EZLs are found in cars that do not have integrated engine management, the fuel delivery and ignition being handled by separate systems, albeit with some communications between them.

EZL may be the wrong abbreviation, strictly speaking, as EZL (Elektronische Zundanlage) translates to Electronic Ignition System. But who cares?

Best.

RayH
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #12 ·
It is the ignition control module. It looks like this:

View attachment 2716676

They come in various flavours and prices, depending on the application? Complex ones as in this picture have 8 pins in those two sockets indicating knock sensors, and probably more.

EZLs are found in cars that do not have integrated engine management, the fuel delivery and ignition being handled by separate systems, albeit with some communications between them.

EZL may be the wrong abbreviation, strictly speaking, as EZL (Elektronische Zundanlage) translates to Electronic Ignition System. But who cares?

Best.

RayH
Thx Ray
 

·
Registered
Joined
·
79 Posts
Quotation: [mikes129]
"Sometimes if you start a car and turn it off quickly it can cause issues. Something to do with the fuel I think, maybe the engine gets flooded. Not much help now, but I like to keep a car idling until the start-up high idle stops and is replaced by standard idle speed."

The above recommendation should not be followed on any car.
The engine should be warmed up as quickly as possible - that happens when you drive the car.
If you go outside in winter and stand still you won't get warm. If you start to chop wood for your fireplace you will warm up.
***
Regarding the EZL modules, I have a 300SL24 with EZL 012 545 20 32 or 21 32.
If mine fails where do I get a replacement module ? New is not affordable here. Used ? But where from ?
Reconditioned ? Warranty ?
 

·
Registered
'96 SL 500
Joined
·
91 Posts
The above recommendation should not be followed on any car.
The engine should be warmed up as quickly as possible - that happens when you drive the car.
If you go outside in winter and stand still you won't get warm. If you start to chop wood for your fireplace you will warm up.
Yes I agree, but if you are starting the car to only move it forward or backwards one or two car lengths (out of the carport or garage). Surely it's better to leave it running for a few minutes rather than switching it off after starting from cold and running for 5 or 10 seconds to perform the vehicle shift. It's not something I would do every day (long idle), and yes, starting the car and driving off in a slow and consistent manner is the best if you intend on actually driving the car at that time. But cars are not always started to be actually driven, as in the case with the OP. OP started the car to back out the carport then turned off and came back 10 minutes later only for it to not start.
 

·
Registered
Joined
·
79 Posts
If you own a car with this type of fuel injection it is a very bad idea to try to warm up the engine or shift it forwards and backwards. This engine runs very rich when cold, plugs can foul up quickly .
If you have a car with a modern engine management it's a different story - even then I would start and drive off.


Car Vehicle Motor vehicle Hood Automotive design
 

·
Registered
Joined
·
28 Posts
I have a 1990 300sl that I backed out of carport shut off for about 10 min tried to start turned over but no start. without shop manuals I'm lost can anyone help. Thanks Ralph
I have sympathy but not much help. I have a i990 300E, M103 engine with same problem. Mine was warm and running perfect, the next morning no spark at the coil. The Crankshaft Position Sensor had been just replaced, also the distributor. After no spark I replaced the coil and what they call the EZL with a used unit from ebay. All I could afford. Still no spark. My right rear tail light and brake light are not working. I have read that later1992 models will not start if the brake lights are not functioning. Not sure if 1990 had this feature. You might check yours. I have a mechanic friend coming by later this week to give me some help. Maybe we can solve both of our problems by sharing info.
 

·
Registered
2004 E500
Joined
·
91 Posts
This exact thing happened to me a few years ago and I was given the solution on another forum. The car ran a short time under rich fuel conditions stripping the rings of residual oil. Remove each spark plug and put about a table spoon of oil in each cylinder. Put the plugs back in and it will fire up. I would recommend pushing it out of the garage as it will smoke like a dragon
 
1 - 20 of 29 Posts
Top