500E does not start

[verkuilm]

Suddenly, my 500E 1991 does not start anymore. De starter works fine, but it does not fire up.
Already searching for a few hours. And I know a few things.
The fuel pump isn't working. The first thing is the relay under the back seat. And there is something strange.
There is a good 12V from the battery. And there is 12V signal from one of the computers. But the last one has no power.
I connected the relay directly on a battery and it works fine. You also can hear it clikking.
So I think there is voltage problem. When I directly connect the fuel pump to the battery it runs fine. But the car stil don't start.
Second, I see a ASR light I'm not sure it was always there.
Im charing the battery now, hope I have a change with a full battery.

Question, Looks like the Base module gives the power supply. The one with the fuses on top. Where got this module the 12V from?
Any other things to do next?

 

[gsxr]

I connected the relay directly on a battery and it works fine. You also can hear it clikking.
So I think there is voltage problem. When I directly connect the fuel pump to the battery it runs fine. But the car stil don't start.

So if you force the fuel pumps ON, the engine still does not start, correct? How about if you squirt a little starting fluid down the ETA / intake manifold, will the engine try to fire (or run for 1-2 seconds) and then die? If so, you are not getting fuel from the injectors.

Question, Looks like the Base module gives the power supply. The one with the fuses on top. Where got this module the 12V from? Any other things to do next?

The Base Module / General Module (BM/GM) is the power supply for the other modules. It gets 12v from the battery terminal, from the smaller red wire at the battery.

Do you have a spare BM/GM, LH module, or EZL to swap for testing? Ideally you should narrow it down to if you are not getting fuel, not getting spark, or not getting either one.

Also - any fault codes / DTC?

 

[gerryvz]

All four of the modules in the CAN box get their power directly from the smaller wire at the positive terminal of the battery in the trunk. It's a direct connection from the battery up to the CAN.

 

[verkuilm]

Great! Thanks. Yess When I force the fuelpump it runs, but the engine did not start. I Chech the fuel line, there is pressure and fuel.
The fuel pump relay get 12V supply from the LH control unit. It gives 12V but no power. So the relay doesn't work. I think the other components which got a signal from the LH control is also without power. I will check de 12V from the battery to the CAN.
I got no spare parts, these cars are pretty rare in th Netherlands.

I have to arrange code reader, will order the LED and a switch. seems like de 500E needs 1mm banana socket.

 

[JC220]

Get a test lamp on a injector plug and see if it is pulsing when cranking. Injector noid test lamps are cheap and ideal for this.

Also get a igntion spark tester and hold it to HT lead to see If you have spark

 

[verkuilm]

thanks! will do! Question. All modulles in the CAN box get there power directely from the battery. No relay? No fuse?
Only the fusses on top base module?

 

[gsxr]

thanks! will do! Question. All modulles in the CAN box get there power directely from the battery. No relay? No fuse?
Only the fusses on top base module?

The BM/GM is powered directly from the battery. The other modules (including EZL) are powered through the BM/GM, I believe. And yes, fused at the top of the BM/GM.

You should consider buying spare modules, both for testing purposes, and for replacement when yours eventually fail. Most are available at a reasonable cost, particularly if you don't need to match exact part numbers, but just use modules that are functionally equivalent (i.e., E-GAS from an .034 instead of .036, non-WOT LH module, etc).

 

[Aaron Enquist]

Suddenly, my 500E 1991 does not start anymore. De starter works fine, but it does not fire up.
Already searching for a few hours. And I know a few things.
The fuel pump isn't working. The first thing is the relay under the back seat. And there is something strange.
There is a good 12V from the battery. And there is 12V signal from one of the computers. But the last one has no power.
I connected the relay directly on a battery and it works fine. You also can hear it clikking.
So I think there is voltage problem. When I directly connect the fuel pump to the battery it runs fine. But the car stil don't start.
Second, I see a ASR light I'm not sure it was always there.
Im charing the battery now, hope I have a change with a full battery.

Question, Looks like the Base module gives the power supply. The one with the fuses on top. Where got this module the 12V from?
Any other things to do next?

I had same issue found out my battery was not charged enough to turn on the fuel pumps. Now i have rough idle problem about to check the distributor caps and rotors. Cheers!

 

[Aaron Enquist]

1992 Mercedes 500E 130K miles one owner all documents and records. Considering selling.

 

[verkuilm]

So I take another look! started again with the relais under the back seat.
12V power is oke, found out this comes directly from the base unit. but with a test lamp, it is oke.
Then the ground, that was not oke. The ground is connected with the LH unit.
Tested the wire from the back of the car to the connector of the LH unit. That is oke.
next thing, check a few things there is a power supply, the ground is oke.
So I opend the LH unit, and there it is, the capictors are leaking. Found her how to change them.
Did that today, and yesssss the fuelpump is running. It worked.
But, no starting there must be another problem.

I also used a test 12v led with a button, but that did not work, strange, it should be really easy.

Is there another output from the LH unit wich i can test?

Next time I will test if there is any power on the injectors.

 

[195910]

Did you hear the clicking sound from the fuel pump relay?
Could it be an Immobilizer/Alarm?

 

[verkuilm]

fuel pomp relais is working now, i can hear run the fuel pump and ther is fuel pressure

 

[Provet]

fuel pomp relais is working now, i can hear run the fuel pump and ther is fuel pressure

If getting spark at plugs then
Next would be crank sensor/cam sensors, if no spark ezl

 

[verkuilm]

Oke I think I've found the problem. Now I got al lights on the dash. I Think my harness is not good. I Can see the upperharness. It is not as bad as my 1994 E200 coupe, but the isolation has gone. Probaly is the lower harness also gone, that I have to check. I found here on 500eboard that a bad lowerharnes gives a lot of warnings on the dash.
It is defently the proof that problem accures on 1991 cars. So got something to do!

 

[Jampad11]

Suddenly, my 500E 1991 does not start anymore. De starter works fine, but it does not fire up.
Already searching for a few hours. And I know a few things.
The fuel pump isn't working. The first thing is the relay under the back seat. And there is something strange.
There is a good 12V from the battery. And there is 12V signal from one of the computers. But the last one has no power.
I connected the relay directly on a battery and it works fine. You also can hear it clikking.
So I think there is voltage problem. When I directly connect the fuel pump to the battery it runs fine. But the car stil don't start.
Second, I see a ASR light I'm not sure it was always there.
Im charing the battery now, hope I have a change with a full battery.

Question, Looks like the Base module gives the power supply. The one with the fuses on top. Where got this module the 12V from?
Any other things to do next?

Check your voltage regulator and then I would check crank shaft sensor located on your engine towards the back fire wall. I’m having the same problem and I’m replacing every part until it turns over. I’ve put in new battery, alternator,voltage regulator, crank shaft sensor , fuel pump, and still looking for a solution. This is getting very frustrating

 

[gsxr]

Check your voltage regulator and then I would check crank shaft sensor located on your engine towards the back fire wall. I’m having the same problem and I’m replacing every part until it turns over. I’ve put in new battery, alternator,voltage regulator, crank shaft sensor , fuel pump, and still looking for a solution. This is getting very frustrating

It cranks but won't fire, correct?

What happens if you squirt some starting fluid down the throttle body - will it fire briefly, or still nothing?

 

[verkuilm]

Yess that is stille the problem. Cranks but further nothing. I have done a few extra things. But so far no succes.
What Is done:
-Rebuilt lower wiring harness was really bad. Terrible job to get out and back again.
-Bought a new orginal upper harness from MB.
Both were really bad. Amazing these cars runs what that kind of bad wiring.
But stil nothing. Dus that is bad news.
Few questions.
A put a multimeter on the connector of a injector. Put on contact and I've got 12volt. Starting, and it fluctueed. Looks good??
I will get a test bougie and see if there is any spark.

Strange thing, and i dont know if that is normal. Putting the ignition on on I got:
-Yellow triangle looks like waring light motor problem?
-ASR on
-ABS on.
Normal??

If the throtle body is broken, should the car fire up? Maybe the wiring there is also very bad? Looks a hell of job to get it out
Thank a lot! The information over here helps a lot.

 

[gsxr]

What happens if you squirt some starting fluid down the throttle body - will it fire briefly, or still nothing?

In ignition/key position 2, all lights should be on in the cluster (except SRS, which will turn off after a few seconds).

Yes, the engine should start with a defective throttle body, unless it has a serious defect.

 

[verkuilm]

so i put a testlight on a injector. Nothing.
Did check the testlight on my w124 and then it works.
so the injection system does nothing.

put a test bougie on wires of both bobines.
nothing. So there is also no spark at al.
Is possible to check cranck shaft sensor? Found the cable. And the connector on the computer.

 

[Rufrob]

Hello. I am having a similar problem.
My car was off the road for 5 years. I put gas in, it would start and stall after a few second. It would not take any throttle. I cleaned the distributor car and rotor. No change. I notice the fuel didnt smell right so I drained the fuel and noticed the tank was rusty inside. So I removed the tank, cleaned it and reinstalled it with new strainer and fuel filter. Now it wont start at all. I hear the fuel pump priming but I could not see any pressure in the fuel rain and no spark. I put power to both FPs directly and they work. So I will try charging the battery again. The harnesses look good with not deteriorated insulation, upper nor lower.
I am not familiar with the 500e so I need to know where the BM/GM are and what else I should be checking. I will check the injectors next too.

 

[gsxr]

If the fuel pumps run but there is no pressure at the rail, you have fuel delivery problems that need to be sorted out first. Also try squirting starting fluid into the intake and see if it fires briefly, if so, you have spark.

The BM/GM is a power supply for the other computers, it is located in the CAN box behind the passenger side strut tower/mount at the base of the windshield.

 

[Rufrob]

Thanks GSXR, you were right. I heard the FP but it turns out only the lead pump was working. I put fuel in the intake and it ran.
So I just ordered a new FP.

 

[verkuilm]

Mine still dont start. Renew the crackshaft sensor, but that does not help.
One thing is sure kow, the EZL 0145454332 doesn't do anything. It should put one site of the coil to the ground. But nothing. Both coils nothing.
I also cheked the enige speed contact to LH injectie computer but also nothing.
-It is broken.
-It gets a signal from an other computer so it decided to do nothing.

Is it possible that the ASR/ABS computer or the LH computer send a signal to the EZL so it doen't work?
For a test I removed al computers exept the base module. But nothing changed.

I removed the EZL and it looks it is changed before, it has a stamp on it M09 93 thats is production year?
What i noticed, the white coollant stuf was not applied correctly.

I be grateful for all help.

 

[gsxr]

M0993 = manufactured in the 9th week of 1993.

Do you have access to another EZL to swap in for testing? It can be from any M119 with LH injection.

 

[verkuilm]

Thanks! oke it is swapped ones! And not done propely. I gone look for another one, But V8 engines pretty rare here in the netherlands.
But saw a few in germany. But gone take a few days.

 

[verkuilm]

Doest a unit from E420 also fit?

 

[gsxr]

Doest a unit from E420 also fit?

Yes, but the timing curves won't be correct. However if you just want to see if the engine fires, you should be able to use a 4.2L as a test; at least for the 013- and 014- part numbers.

 

[verkuilm]

Thanks, clear, explains the price differences, the 5.0 much more expensive. But will get one!

 

[verkuilm]

Will look for another EZL.
I openend this one. See picture.
The EZL does not work. Cranksensor is new and there is +12 and an good ground.
Is it possible the LH injectie module sent a signal to the EZL so it wont work?

 

[verkuilm]

So I got a used EZL 0135456432.
And YESSSS the cars fired up! at least. So that is nice.
Let run the engine for few minutes. And than got a other issue.
When warm, it starts to misfire at iddle. If I rev the enige it seems oke.
Turn off the engine.
And start it again, but it doesn't. it is trying, got some live in it but not enough.
I think got a few things:
-The used EZL is not okay.
-Crackshaft sensor is new, mabay at the shim of 0.5mm
-LH injection, I changed the capicitors.
-Distribution cab and rotor, looks not that good.
-Coils?

Pretty hard to get the car running! Try tomorrow again with cold engine.
Thanks for advise so far

 

[gsxr]

- The used EZL should be fine, because the engine started & ran normally for a while.
- New crank sensor is probably fine, if there are no codes on the EZL
- LH is usually not related to misfires
- Distributor cap & rotors, if not recent, may need replacement along with the insulators. And, inspect for liquid behind the insulators.
- New coils are a good idea if old/original, if inexpensive you could try that first and see if there's any change.
- Pretty likely the engine will start right up again when cold. And, if you waited 1-2 hours, it may have restarted, if the issue is secondary ignition system.

 

[verkuilm]

Yesterday I clean up the distibution caps, Rotorts and isolators. I have to order new ones. They ar used.
Started the engine, and yess real good. Let it idle for few minutes. Drive a little bit. And all okay. Let it idle for few time.
Engine was all heated up.
Turn it off, wait 15 minutes en start it again. Nothing. Remove the caps, and the left one was full of moisture. Clean both caps.
Now it starts runs for one seconds en dies.
Wil try it today with cold engine.
So I orded new caps, rotos and isolators and seals.

Read a lot of post of this kind problems. So I gone renew all parts.
The only connections I dont see, there must be a problem with the carter breather hose?

Thanks a lot!

 

[Eno]

Check the electrical ground and make sure there is proper power supply into the fuel pumps.

 

[verkuilm]

Stil have some trouble. Starts, runs for a second and die. Did use a fuelpressure meter today. Looks like the pressure is far to high. If i drain the retour line so it is empty the cars runs for a minute. I made short film, will try to upload it.

 

[gsxr]

What was the pressure?

 

[verkuilm]

55psi stationary I have to give some gas to keep it running. Giving gas is lowers too 48PSI
I blow the return hose, but looks free.
Started again and then runs great for a minut, stationary 45 PSI. Then suddely the pressure goes up and engine dies.
I changed the fuels pressure regulator by a bosch, but it is also from rockauto. I got some some trouble with parts from rockauto.

So I'm pretty sure there something wrong, fpr wrong or return house had to much resistance.
Will order an other fpr tomorrow.
Or is there somethings els wich effects the pressure?

 

[gsxr]

Those pressures sound normal. Spec is 3.2-4.2 bar (46-61 psi). Pressure at high end of spec will not cause the engine to die. You can remove the vacuum hose at the FPR and watch the pressure jump to ~60psi but the engine should keep running.

 

[verkuilm]

But the presure should be kind of stable? It is not. And idlle more presure then rev the engine. I shall try to share the video.

 

[gsxr]

Pressure should be 3.2-3.6 bar at idle, and should increase if you rev the engine.

 

[verkuilm]

My first movie on youtube

 

[gsxr]

Fuel pressures are normal, although the needle vibrates a bit. As the engine stumbles, intake vacuum is reduced, which increases fuel pressure.

The fuel pressure changes [within factory specs] are a result of the engine stumbling, not the cause of it.

 

[verkuilm]

Oke thanks for the reaction. I'm not sure what I should expect.
The car should run at idle when the vacuum hose is disconnected?
The engine can handle the higer pressure?

 

[gsxr]

Oke thanks for the reaction. I'm not sure what I should expect. The car should run at idle when the vacuum hose is disconnected?

Yes, the engine will run fine at idle with the hose on or off. You may notice a brief change in RPM as the hose is connected/disconnected.

The engine can handle the higer pressure?

With the hose removed, pressures increase, and the mixture will be richer. If you left the hose off, the LH module adaptation would change leaner over time, compensating for the richer mixture. Obviously you don't want to leave it off long term, but the engine will run fine and the car will drive OK as well, with the hose disconnected.

 

[verkuilm]

Thanks a lot for the feed back! Then probaly the fuel pressure is oke. Wil just for sure on more more time.
En then I wil try to keep the engining run for some longer period.
Then to look further for the problem.

 

[JC220]

Suggest you buy a blink code reader, clear all codes. Run and after fault occurs read all blink codes again.

Search the forum please all info if available on blink code reader and the document for correct codes translation.

 

[verkuilm]

So I get in my vanclee Mungo, (salt on the roards so no coupe) And get another change at the 500E
I did change the fuel pressure regulator, I dont trust Bosch parts from rockauto. Just bought at arround the corner, right on time, we haven another lock down for 5 weeks......
The presure is more constant!

The engine suddenly dies at 1:20min. Looks like ther something hapopeing after 60 seconds, air pump or something.

And yess got some codes:
LH-SFI ->11 secondary air injection system, open circuit
Base module ->6 electromagnetic a/c compresure clutch blocked
Diagnostic module -> no reaction
Distibutor ignition ->27 control module data exchange fault
next time wil take more time for more codes, if there is.

Thanks for the information

 

[gsxr]

Are you touching the accelerator pedal and holding RPM's at 1200+? The idle speed should not be that high, even at cold start.

 

[verkuilm]

Dat is me indeed. I speed it up. See if it quit with 1200 rpm. So the problem is probaly not vaccuum.
Otherwise it will do 600. Normal.

 

[verkuilm]

Still trying to fix the 500E. Gives us hard time!
Make a short movie.
The signal is taken from the minus of one of the bobines:

Yesterday I change the caps and rotors, bought at MB, expensive,(MB box, inside Bosh )
But same result.
Next we will change Both bobines.
If the problem still excist, We will find another EZL.

 

[gsxr]

Definitely replace both coils (bobines) next, with Bosch. Hopefully that will take care of the problem.