1992 300E (W124) no start (no spark)
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From: Chicago
2025 AMG E 53; 2018 GLC300 4Matic; 2003 360 Modena
1992 300E (W124) no start (no spark)
Hello All:
Replaced the original cap and rotor when this happened approximately 2 months ago. It was the original cap and rotor.
Car died and won't restart, spark is reaching the cap via the coil wire - but nothing to the spark plugs.
Before I rule out a bad cap, anyone have any other thoughts?
Thanks
Replaced the original cap and rotor when this happened approximately 2 months ago. It was the original cap and rotor.
Car died and won't restart, spark is reaching the cap via the coil wire - but nothing to the spark plugs.
Before I rule out a bad cap, anyone have any other thoughts?
Thanks
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From: Los Angeles
2013 Infiniti G37 Coupe; 2011 GLK 350 w/ Premium 1, Multimedia & Sport Appearance; I LOVE IT!
Cap is so easy to replace why not just do so rather than wait for forum replies?
Did you use an OEM or comperable-quality brand cap?
Do you have the one you took off to troubleshoot?
It really isn't rocket surgery...
Did you use an OEM or comperable-quality brand cap?
Do you have the one you took off to troubleshoot?
It really isn't rocket surgery...
Thread Starter
MBWorld Fanatic!
Joined: Jun 2005
Posts: 1,512
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From: Chicago
2025 AMG E 53; 2018 GLC300 4Matic; 2003 360 Modena
Used an OEM Bosch.
Not being rocket surgery, I figured I'd put the problem to the group just in case I'm missing the obvious.
Will also troubleshoot with the old one.
Thanks
Not being rocket surgery, I figured I'd put the problem to the group just in case I'm missing the obvious.
Will also troubleshoot with the old one.
Thanks
MBWorld Fanatic!
Joined: Aug 2010
Posts: 1,136
Likes: 7
From: Los Angeles
2013 Infiniti G37 Coupe; 2011 GLK 350 w/ Premium 1, Multimedia & Sport Appearance; I LOVE IT!
Don't mean to bust your *****.
Basic trouble shooting: If something doesn't work after you made a change, undo the change.
Good luck with it!
Basic trouble shooting: If something doesn't work after you made a change, undo the change.
Good luck with it!
Thread Starter
MBWorld Fanatic!
Joined: Jun 2005
Posts: 1,512
Likes: 267
From: Chicago
2025 AMG E 53; 2018 GLC300 4Matic; 2003 360 Modena
And I'm not looking to bust yours - rather, looking for some insight from someone that can actually contribute.
No ***** sherlock - of course I can swap the cap and rotor, as a new defective is not unheard of. Given the experience that reads the forum, I was more interested in someone who might have experienced the same problem.
Maybe a speed reference sensor that is defective that in spite of feeding the EZL unit, could prevent spark from the cap to the plugs.
Or, even though the coil is still feeding the cap with strong voltage, the EZL actually controls the spark to the plugs (along the likes of a wasted spark function).
I'm all for meaningless banter, but when it's cold outside I'd rather spend my time with some insight and experience as I do the work rather than "rocket surgery" and "you made a change, undo the change".
No ***** sherlock - of course I can swap the cap and rotor, as a new defective is not unheard of. Given the experience that reads the forum, I was more interested in someone who might have experienced the same problem.
Maybe a speed reference sensor that is defective that in spite of feeding the EZL unit, could prevent spark from the cap to the plugs.
Or, even though the coil is still feeding the cap with strong voltage, the EZL actually controls the spark to the plugs (along the likes of a wasted spark function).
I'm all for meaningless banter, but when it's cold outside I'd rather spend my time with some insight and experience as I do the work rather than "rocket surgery" and "you made a change, undo the change".
MBWorld Fanatic!
Joined: Aug 2010
Posts: 1,136
Likes: 7
From: Los Angeles
2013 Infiniti G37 Coupe; 2011 GLK 350 w/ Premium 1, Multimedia & Sport Appearance; I LOVE IT!
If you really want meaningless, try asking for opinions before doing some basic troubleshooting. 
If your mechanical ability is anything like your reasoning you most likely installed the new cap and rotor wrong.
If your mechanical ability is anything like your reasoning you most likely installed the new cap and rotor wrong.
Thread Starter
MBWorld Fanatic!
Joined: Jun 2005
Posts: 1,512
Likes: 267
From: Chicago
2025 AMG E 53; 2018 GLC300 4Matic; 2003 360 Modena
Follow-up:
I re-confirmed that the fuel system is in order and concentrated back on the inputs to the EZL. I was able to get a list of inputs and test requirements from a local dealer. While not everything was perfect the inputs weren't far off. The speed sensor was the weakest, but the result of buildup at the pickup and corrosion at the connector, not a defective sensor. Once cleaned up, it met spec.
Given that the car is 18 years old, all the connection left a little to be desired, so a thorough cleaning of all connectors including the vacuum line were cleaned.
Car started just fine. While my initial test for spark from the coil wire was good, it was only firing one plug directly connected. When tasked with supplying power to 6 plugs - no go. Age took it's toll and weakened coil output and ultimately the spark to the point the car wouldn't run. The real relief is that the dreaded wiring harness problem that plagues W124's isn't the cause.
(As for the jerk who couldn't muster a diagnosis, help or anything constructive in 3 tries: Please save yourself and, for that matter, everyone the time and not ruin a post seeking help from the MBWorld knowledge.)
I re-confirmed that the fuel system is in order and concentrated back on the inputs to the EZL. I was able to get a list of inputs and test requirements from a local dealer. While not everything was perfect the inputs weren't far off. The speed sensor was the weakest, but the result of buildup at the pickup and corrosion at the connector, not a defective sensor. Once cleaned up, it met spec.
Given that the car is 18 years old, all the connection left a little to be desired, so a thorough cleaning of all connectors including the vacuum line were cleaned.
Car started just fine. While my initial test for spark from the coil wire was good, it was only firing one plug directly connected. When tasked with supplying power to 6 plugs - no go. Age took it's toll and weakened coil output and ultimately the spark to the point the car wouldn't run. The real relief is that the dreaded wiring harness problem that plagues W124's isn't the cause.
(As for the jerk who couldn't muster a diagnosis, help or anything constructive in 3 tries: Please save yourself and, for that matter, everyone the time and not ruin a post seeking help from the MBWorld knowledge.)
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MBWorld Fanatic!
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From: Los Angeles
2013 Infiniti G37 Coupe; 2011 GLK 350 w/ Premium 1, Multimedia & Sport Appearance; I LOVE IT!
I was going to suggest you install some AMG door lock pins but I assumed you had already tried that...
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