Mercedes-Benz Forum banner

1 - 15 of 15 Posts

·
Registered
E500(1993) E220cdi(2004) SL500(1994)
Joined
·
282 Posts
Discussion Starter #1
Guys, a quick question here as I'm about to go on holidays in a couple of days :

Everything was fine with my car until I changed the fuel filter about 3 weeks ago. Indeed, just after changing the fuel filter the engine started cutting out and hesitating heavily! I don't know if it is a pure coincidence or if it is related to the new fuel filter(which was a German made quality filter I believe was "Knecht"; I didn't find a OE MB filter); but my nightmare started right after this replacement!

Prior to that I had a slow reacting engine, poor acceleration, some misfires and I definitely knew that fuel pressure was weak.
Anyways, the symptoms I'm currently experiencing are : engine cutting out just after I would drive for 5 miles or so(upon cold start). It would start just fine, idle very well, no misfire, no shaking whatsoever; but as soon as I would drive for 5 or 7 miles and especially if I would stop at a roundabout or a stop sign and then re-accelerate to move again it would be as if the engine would die on me! Moreover, if I would accelerate strongly it would die anyway(with a small detail just half a second before that : the battery warning lamp on the dash would trigger!)
Now, I spare some other details, and the usual inspections I think you would ask me to do :

1/- I thoroughly inspected the caps and rotors I've already replaced about 2 months ago. They are in neat condition. I even went ahead and removed the rotor arms and the the orange dust shields behind them(I am aware of the numerous driving issues these 2 plastic caps can cause if deteriorating). I thoroughly cleaned the small amount of moisture and corrosion I've found around the cam housing and sprayed some silicone grease on the plastic shields. I'm absolutely convinced there is no issue whatsoever with the caps&rotors.

2/- No issues with the plug wires(replaced about 2 years ago); the plugs are original MB non-resistor and have only 25000 km on them. I checked them at idle by removing each lead over each plug and they are fine.

3/- Of course I thought about the ignition coils and replaced them both with a couple of Bosch coils I've purchased new 3 years ago and used on another car. I know for sure they are fine.

4/- No issue whatsoever from coils to plugs.

5/- I also thought about a fuel issue but it sounds more ignition than fuel. My FPR and fuel pumps were recently changed as well. And to rule out a possible fuel pump relay issue, I replaced it last week.

To tell you, I'm more tempted to think about a possible battery issue(the actual one is a big Bosch battery; 4 years old). Even though I'm reading 12.6 V with my multimeter with engine off and 13.5 V with engine on. The alternator had its VR replaced as well about a year ago. So I'm assuming it's ok with it.

6/- The serpentine belt is new as well; replaced 3 months ago.

Another clue : about a month ago my windshield wiper stopped working(it started to move very slowly until it stopped compltely). Today my exterior auto-folding mirror started too to move very slowly... Also I noticed that when I turn the headlights on, a small drop in the rpm at idle would occur...

Finally, and since 2 months or so, 1 day I was working on the fuse box to clean the fuse clips I measured the voltage by curiosity and noticed that none of the fuses was reading 12 V ! most of them were reading between 8.5 to 11 V only! I don't know if they are supposed to show such readings... Again today I measured them and the same readings happened. With engine ON they will show between 10 to 11 V only!

Is it supposed to be like that?? I don't think so...

Could it be the iginiton switch going bad?? I replaced it twice in the past because of bad voltage issues and I hope I won't have to replace it again...

What could possibly be wrong this time???

Could the EZL be the culprit?? The battery??? Any possible relay???

Please guys can someone help me out?? I'm going on holidays in about 4 days and hope to solve this problem before I leave...

Sorry for the long writing but I wanted to spare you the unecessary questions.

Thanks in advance!

Regards
 

·
Registered
E500(1993) E220cdi(2004) SL500(1994)
Joined
·
282 Posts
Discussion Starter #3 (Edited)
Do you still have the old filter? If so, try putting it back in.
Hi CalCiCi!

Thank you for the interest in my problem!

Well it was very old and I directly noticed the difference when I replaced it...

Do you think it could still be the filter??

Oh! I forgot to say that I tried driving with the MAF connected and disconnected and no change whatsoever. It's still behaving the same way... The air filters are still ok too.
The wiring harness+ETA wiring are ok as well.
 

·
Registered
E500(1993) E220cdi(2004) SL500(1994)
Joined
·
282 Posts
Discussion Starter #4
Guys...

Need your help please...

Could it be a fuel issue anyway?? May be the new filter is a bad one??
Or could it be one of the fuel pumps starting to fail?

If it was indeed an igition issue, besides all that was checked out, could it be the EZL or the ignition switch?? I can't think of anything else besides these 2...
 

·
Registered
E500(1993) E220cdi(2004) SL500(1994)
Joined
·
282 Posts
Discussion Starter #5
Update :

I thoroughly inspected the alternator and the battery with a multimeter with engine ON & OFF and they both are OK : 12.6V with engine OFF and 14V with engine ON with all type of accessories working inside the car(radio/AC/headlights). The voltage on the battery barely drops...

But now it seems that even with cold engine if I suddenly step on the gas pedal it would die instantly with the battery warning lamp blinking just before the engine dies. I anyway think may be is it like that because the battery at that precise moment isn't getting any power from the dynamo...

What the hell is going on??? What could happen to a healthy engine like this???

Could it be a fuel issue??

Any suggestion fellows??

Thanks in advance...
 

·
Registered
E500(1993) E220cdi(2004) SL500(1994)
Joined
·
282 Posts
Discussion Starter #9
Yes! by the previous owner.

One thought: Could it anyway be one or more spark plug??

I say this because it seems like it's a coil issue(same symptoms) and I feel like there is like one or 2 cylinders not firing or firing late so the engine hesitates while accelerating from standstill and also when I push on the gas pedal like when I'm at 120/140 km/h and wish the tranny to downshift>>> it hesitates at that point before downshifting because there is loss of power...
I didn't remove the plugs; just unplugged the leads to try to check if they were firing. They are original MB (not Bosch; Beru or another make) and have almost 30000 km on them.
I don't mind changing them again, but why I didn't suspect them was because no misfire was felt at idle or starting issues exhibiting at all...
 

·
Outstanding Contributor
R129 500 SL 1991
Joined
·
1,038 Posts
Check voltage at fuses again with ignition on. Make note of fuses down on voltage. Then remove key, reinsert and cycle key few times. Ignition on, off, on... then recheck voltages. Any change?
 

·
Registered
E500(1993) E220cdi(2004) SL500(1994)
Joined
·
282 Posts
Discussion Starter #12 (Edited)
Yes! by the previous owner.

One thought: Could it anyway be one or more spark plug??

I say this because it seems like it's a coil issue(same symptoms) and I feel like there is like one or 2 cylinders not firing or firing late so the engine hesitates while accelerating from standstill and also when I push on the gas pedal like when I'm at 120/140 km/h and wish the tranny to downshift>>> it hesitates at that point before downshifting because there is loss of power...
I didn't remove the plugs; just unplugged the leads to try to check if they were firing. They are original MB (not Bosch; Beru or another make) and have almost 30000 km on them.
I don't mind changing them again, but why I didn't suspect them was because no misfire was felt at idle or starting issues exhibiting at all...
Check voltage at fuses again with ignition on. Make note of fuses down on voltage. Then remove key, reinsert and cycle key few times. Ignition on, off, on... then recheck voltages. Any change?
I did.. and it seems it is the same no matter how many times I cycled the key On/Off! No change in the voltage. Oh! and one thing I noticed is that the voltage at fuse 11 was a bit lower than the others (with engine Off the voltage is around 10V and with engine On it is around 11V only). This is btw the fuse which controls the wiper system. And to test my wiper motor I connected fuse 10 and fuse 11 together using an electric wire and turned the wiper ON and it started right up as before! That's good news but I will have to solve this problem asap!

One more thing, I always had an electric issue with the iginiton switch which comes and goes intermittently and Only at startup : from time to time there is no sign of electric power on the cluster. On position 1 using the key, there is always power to the radio/electric seats/mirrors; but sometimes no cluster lights on position 2 ! I have to cycle again 2 or 3 times to get the cluster to illuminate again... I tried to see if it was a cluster issue or an ignition switch issue, so at that particular moment I sometimes try to start the engine and it would start most of the times... Therefore, I'm not sure if it is a 100% cluster or ignition issue.

I swapped the iginiton caps&rotors with a known good set I removed from a good working engine I personally drove last year, and besides an overall improvement in the power(stronger acceleration/better shifting and quicker engine response) the hesitation/cutting is still present!
It is still there and I don't know what to look for right now after I checked & swapped all the electric parts I thought about!

It is exactly as a bad coil symptoms... what could cause this kind of issues besides a bad coil/bad alternator/bad cap&rotor/plug wires ???
The CPS???
It is a mystery for me I have to admit...
 

·
Registered
2002 SL500 Silver Arrow
Joined
·
644 Posts
The only stalling issue I ever had was CPS. Happened when warm, and when coming to a stop. At first intermittent and then more frequently. Quick, reasonably easy job. Never and issue. Only difference from what you are describing was that I do not remember the car running poorly between stalls.
 

·
Registered
E500(1993) E220cdi(2004) SL500(1994)
Joined
·
282 Posts
Discussion Starter #15
Could it be a dirty injector acting like a bad coil at the end??
 
1 - 15 of 15 Posts
Top