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1983 380SEC, 1991 560SEC, and old porsches
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13 Posts
Discussion Starter #1
My 1991 560SEC motor decided to momentarily quit running on a return trip from Florida about 6 months ago It started, about 2 hours into the trip, quit then ran for an hour then quit and again ran for a while. By the time we reached Gulf Port for the night it was quitting and not firing up again after its then normal 1 to 2 second pause but would restart right away. I got to Texas and home, and had my mechanic friend look at it. His solution was to change cap/rotor/wires/plugs and the neutral safety switch. He also tightened the ignition switch as the tumbler was loose.
None of these solved the problem. Shes still is unreliable and cuts out from time to time. We had planned to substitute the Ignition Control to see if it would make a difference. We can not find the proper ignition control unit to try this tactic. The MB number is 004 545 5332 [02] and the Bosh number is 0227 400 624. Is there any cross reference on the control units available as to which can be substituted? I am thinking of sending this unit to Programa for bench testing. I called them and they said they dont list the unit in their rebuilt items list, and I haven't found an aftermarket site that does. I have also determined that I get some AC voltage from the crankshaft position with the ohmmeter. The car runs so the coil works but the hesitation is the same as if a chevy coil 12v/8v wire is broken and intermittent. Any thoughts? Can Programa bench test the unit? Its $100 to send it to them plus the ups costs. Any help would be appreciated.
 

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1993 300TE, 1995 E320 Wagon
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1,895 Posts
I think many of the EZLs are interchangeable on the v8s. I have a couple of EZLs available (tested good on my 1990 560SEL, same engine as yours unless you have a euro greymarket). I've never seen a 5332 in the yards-- lots of 5532s though... check the numbers again??

I would also suspect the fuel pump relay and/or the OVP as going out intermittently. I have all of these available for reasonable cost.

As to sending to Programa-- it might be worthwhile, but if the EZL comes back as good, you're out $100+ and no further long. Is there anyone near you with a "known good" EZL/OVP/FPR that could be swapped in?
 

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1989 560SEC
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2,056 Posts
Sounds like a EZL problem I had where the motor was stumbling and I limped home. I purchased a tested EZL from El Rojo and no more problems. I would by the parts from him. This will buy a few more years on the clock.

Mike
 

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1983 380SEC, 1991 560SEC, and old porsches
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13 Posts
Discussion Starter #4
Thanks for the quick answers. MB part number is 004 545 5332 [02] EZ 0017. Above the bar code is BOSCH 0227 400 624. This cars history is originally from southern California and perhaps that is the reason for the odd ball EZL number. I am anxious to get the car reliable and pleased to know that the V8 EZL is interchangeable. Fuel Pump Relay? Pump runs good, Filter has been changed not to long ago. But the relay is a good guess. OVP? you got me there! I don't know what that is nor where it is. I have removed the EZL and there is a bunch of white powder on the back side where it mounts on the fender well. This could be some kind of oxidation but the case seems to be hard plastic. So I am getting a NO COMPUTE in my mind on this. Please let me know what your parts will cost as I am anxious to get this car reliable again.
Mike
 

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84 500SEL AMG, 90 560SEC AMG, 85 500SEC AMG Widebody
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1,808 Posts
I also have a 91 SEC and just went through a similar situation. Here is the scoop on what you are facing.

Do not automatically think the EZL (ignition control module bolted to the inner fender wall in the engine bay) is the culprit. My SEC also went through an engine dying situation a couple of weeks ago. In my case, it was the Fuel Pump Relay located between the two firewalls between the large ABS connector and the Klima module. The FPR module is P/N 003 545 25 05 and can be purchased from parts.com (MB OEM supplier) for $55:

Auto Parts - Parts.com, For Every Part of Your Life

These are known to go bad and many W126 people replace these and also carry a spare in the trunk. This module keeps the fuel pumps running - if it fails (intermitently, car dies). You can also "jumper" two of the pins to keep the fuel pumps running (do a search on "jumper FPR"). I bought two new modules - one to use and one for the trunk. No issues since.

The EZL is also a known item that, over time and heat, may fail. These are hugely $$$$ to buy new ($1,700 +). Many W126 owners buy a used one off eBay and keep it in the trunk as well.

EZL 004 545 55 32 was the original MB Part # for a 91 SEC, superseded by
EZL 004 545 53 32 Bosch P/N 0 227 400 624 which was also superseded by
EZL 010 545 67 32 Bosch P/N 0 227 600 495 is the current P/N for sale by MB

Any of the above will work in your car and many used units are for sale on eBay ranging from $30 to $500. The older units (55 32) are typically cheaper than the later units (67 32). I bought a "used" 67 32 EZL for $250 that I swear is near brand new and must have been recently changed before the donor car was parted out. I tested the unit when I got it and stuck it in the trunk with my new FPR. Note that Siemens also made these EZL's, so you may see them for sale along with the Bosch units.

The final possibility is the coil MB P/N 000 158 64 03 that may also go bad. Parts.com or ebay new cost around $100.

Your mechanic doesn't know much about W126 cars if he did all the things you mentioned and didn't look at the FPR, EZL and Coil as the most likely issues. All three of the above items are very simple to install with basic tools - no need for a mechanic.

I suggest you try the cheapest alternative first (new FPR), then a used EZL then a new coil.

EDIT - just re-read your last post. The white powder under your EZL is heat sink paste and is critical to transferring heat from the EZL to the chassis - you must have this in place or your EZL will surely die. You can buy this paste from Radio Shack for a couple of bucks. You also need to keep the plastic sheet! Also, a dying FPR can show itself as an intermittent problem as opposed to dying all at once.
Al
 

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1983 380SEC, 1991 560SEC, and old porsches
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13 Posts
Discussion Starter #6
Al Lydon,
Thank you so much for your insight into the repair on my 91 560SEC. I will follow your advice to the letter. I have the early MB 126 shop manuals which I bought for my 83 380 SEC. The 91 is clearly a different setup. I am wondering how you came up with the succession of EZL part numbers. I have a MAC Air computer and the MB catalogue on this site can't be downloaded to a MAC. Is that were you got the numbers and replacement numbers for the EZL? That kind of information really helps.

Fuel pump relay first, then EZL followed by the coil. Spares in the trunk prior to the next long trip. Thanks again.
 

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84 500SEL AMG, 90 560SEC AMG, 85 500SEC AMG Widebody
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1,808 Posts
You can get full access to all MB parts via the MBZ EPC (Electronic Parts Catalog):

https://epc.startekinfo.com/epc/home.jsp

For US residents and US cars, it is free. The site will ask for a credit card #, but no charge for US residents. The application requires the latest Java app to download. Once in, you simply type in your VIN and you get access to all parts for your car. There are no prices - just part #'s and pictures (both of which you can print). If there are parts that are superseded, it will show all of the old and new part #'s.

Good luck with your SEC.

Al
 

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1983 380SEC, 1991 560SEC, and old porsches
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13 Posts
Discussion Starter #8
Just got the fuel pump relay in the mail. I will install it today and replace the Ignition Control module (EZL) after getting the Radio Shack heat sink paste for the backside. I will post the results of the repair as soon as we test drive it for a bit.
Thanks to all for the help so far. I have hopes that this will solve my problem.
 

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Premium Member
1991 560 SEC 1994 E500 2014 E350 Cab
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7,029 Posts
Sent you a PM Michael:thumbsup:
 

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1985 500 SEC EURO AMG/LORINSER; 1988 560SEL, 1995 S500 Sonderschutz
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3,679 Posts
Just got the fuel pump relay in the mail. I will install it today and replace the Ignition Control module (EZL) after getting the Radio Shack heat sink paste for the backside. I will post the results of the repair as soon as we test drive it for a bit.
Thanks to all for the help so far. I have hopes that this will solve my problem.
Results?
 

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Premium Member
1991 560 SEC 1994 E500 2014 E350 Cab
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7,029 Posts
Just want to vouch for Al and Dave (not that my opinion matters) but I did buy an EZL and the FPR for that very reason on my 91 from ElRojo and they both improved my circumstances discussed here. If Dave has checked them out, they are good an if the USPS puts a hex/vex on them, he stands up for it! Great advice and great parts source!
 
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