RKramkowski

Hi I have a 1987 W124, 260e, I think, but the car has been de-badged. I'm getting absolutely no fuel flow at the engine so I suspect the fuel pump. Generally if the filter is clogging, I would expect at least a trickle of fuel.

I had a 1991 190e awhile back and changed out the fuel filter and pumps on that one. But on my 1987, the fuel pump and filter aren't at the rear next to the tire/differential on the driver's side where I'd expect. I have looked at the on-line manuals at w124-zone and my pump/filter isn't there. Is it possible that the pump/filter are in the tank? I read somewhere about the filter/pump being accessible through a panel under the rear seat on some models. But before I start tearing things apart, I wanted to be sure where it is. Any ideas? I don't know if it makes a difference but this car was built in South Africa.

optimusprime m1

You can try removing the fuel relay .Its at the rear of the battery, at the back of the plastic finisher ,you then bridge no 7 and 8 in the connector this will put the pump on all the time .So you can check ,if it wont start right away turn iyt off ,or it will flood the engine..This is used for a check only. Your pump, or pumps ,as some had two, are situated in front of the rear wheels in the uk its passengers side . It will have a cover over the unit , so maybe thats why you had not seen them Another thing to look in to is all your fuses if they are silver bayonet type get copper or brass .In the mean time give them a turn.in the holders. I will send you this checking chart

optimusprime m1

This may help, Also do this Google search -- Model 124 Maintenance Manual Index.
All you will ever need for W124 . You have the very same car as mine w124 260e m103 please let us know how you get on .

RKramkowski

Thanks,

I'll try the relay test first. I was also going to check the actual voltage at the pump, but even if the relay is working properly, I'd expect to see only a momentary voltage jump until the relay cuts out.

optimusprime m1

RK next to the relay is another box a little larger in size .On the top it will have a fuse some have two ,check the fuse is ok .To remove these its a pain i am afraid .For some reason they wont pull out from the bottom .It as a locator that clips in to the holder .Dont damage it ,its not that strong.Another is earth points .Remove the bolt clean them up put a dab of grease on and re fit .One or two by the coil , and from clutch housing on to the body ,and on the spring turet by the batery. If you check the manual i sent to you all the checks are in there, and how to go about it

RKramkowski

OK, so I pulled the relay and jumped pins 7 and 8 and got fuel flow. I wrapped a wire around those posts and plugged the relay back in and the car started! So I guess it's the fuel pump relay. Of course I pulled the relay and didn't leave the jumper in so the pump wouldn't always be energized. So unless anyone thinks differently, I'll be looking for a new relay.

optimusprime m1

Rk looks like you have found the problem .Now open up the relay, and see if you can re solder the joints ,just heat them up ,let them go cold again. I works some times. I have the number of the relay you need .So let me know if you need it .

RKramkowski

Thanks, I'm going to match the relay number on the case and am off to a salvage yard now. I popped the cover off the relay and could see nothing wrong with any of the solder joints, components, or relays themselves. So I'm hoping replacing it works.

optimusprime m1

RK please let us know how you get on.

RKramkowski

So far no luck. Being Sunday, many of the yards are closed. The ones I checked out were already picked through. I'm going to try a few more tomorrow. I may end up just purchasing one from eBay but I notice many don't appear to be "genuine Mercedes parts".

RKramkowski

I believe the part I'm looking for is 002 545 52 05. I found somewhere in a thread that it's interchangeable with 003 545 17 05 or 003 545 24 05. As far as you know, would that be correct?

optimusprime m1

RK My relay is 003 545 24 05 260 E 1989 M103 engine automatic no climate control. I purchased a spare from Ebay last year .Checked in the car and works fine Original one is 27 years old with same number .So it is the right one for my car. And for yours.

RKramkowski

I'm getting incredibly inconsistent symptoms. Just to recap:

I was driving, coming to a stop at a traffic light and the car just died. No warning. It would crank over and over but no signs of starting. Upon investigation, it had no spark. After a number of things, I ended up replacing the coil and the main spark wire between the coil and distributor. In the process, I cleaned the ground at the coil and coil terminals. This got my spark back. But the car still wouldn't start. The CPS is getting 850 ohms, right where it should be. So now it seemed to not be getting fuel. I disconnected the fuel line at the fuel distribution inlet and got no fuel flow whatsoever. I suspected either the fuel pump or relay. If the filter, I would have suspected at least a trickle since filters generally clog over time. That's what happened with my 190e. So I pulled the relay and jumpered pins 7 and 8. I now get fuel flow so it appears the pump is good. In fact, I was able to start the car with the pins jumped.

My original fuel pump relay was 002 545 52 05 which was confirmed by the shop manual. I couldn't find that one locally, but did find 003 545 24 05. This was confirmed by the shop manual as the correct one for the 1993 model year but I found cross references that indicated that it should work. The only things to note are that my original relay says kickdown on it and also only has three pins along the one side whereas the 1993 variant has four pins.

So I plugged the 1993 relay in and now I get fuel flow when I turn the key but it flows for a short while and then stops. This appears consistent with the manual where it says that initially the relay pulses the pump so as to pressurize it and then once the car starts, it keeps the fuel pump energized. But the car still won't start. It cranks and once in awhile will chuff like it wants to start. But before all this, it would just crank with no indication of starting. Just as I turn the key to the off position, it almost seems like it wants to start.

So just "because", I opened both relays and even though nothing looked amiss, I resoldered a few of the connections that looked the "worst". Now both the original relay and the 1993 relay both act the same. Both get fuel flow, both get the occasional chuff, but neither will start the car. And now, if I jumper pins 7 and 8, I get fuel flow, but the car will no longer start. I still have a strong spark. I also followed the test steps in the manual for fuel pump relay testing. Steps 1.0 through 1.4 are all in-spec. I couldn't find S16/7 (the kickdown switch) in order to test 2.0 - 2.4. The diagram just doesn't give me enough info as to where to fin dit.

I'm at a total loss as to where to look next. I didn't measure the fuel flow or pressure (I don't have a gauge) but the flow appears strong. Could it still not be sufficient? Could the filter be clogged "just enough" so it wouldn't start? If so, I'd expect to be able to start it, just not keep it running. And I wouldn't have expected to be able to start the car while pins 7 and 8 were jumped as when I first attempted that test.

optimusprime m1

I am stuck with this one .You said you had bridged 7 8 0n the board to get fuel.But then you talking about a nother relay with kick down on it The kickdown as nothing todo with the starting of the engine. Just dont do anything else , till you have it running . If you have spark .The next step is fuel .If you have a problem in the fuel line .like filtter or accumulator will another item to check out.You will make the problem worse if you dont get one thing sorted first then go on to another one.Do you have a rotor arm spare? The kick down relay is the wrong one to work on. The extra pins are in the antway some are not used .

RKramkowski

It's the same relay. It says kickdown on the relay body. The kickdown switch is also part of the test procedure for testing the fuel pump relay at
http://www.w124-zone.com/downloads/M...07MechElec.htm

What's odd is that I have both spark and fuel. I'm going to replace the distributor cap and rotor and fuel filter this weekend and see if it makes a difference.

optimusprime m1

RK your right, and i gave you the link to the manual haha . I have replaced mine from a seller on Ebay .And pluged it in to prove i had a good item from the seller. Same number and fine .Dont rewmove items when the key is in start possition or you will have more problems. It should run ok if spark and fuel .Did you check the relay, the one with fuses on the top. Thats if it wont start . Turn all fuses as i asked .

RKramkowski

I did turn all the fuses and checked the fuse on the OVP relay. It's good. I haven't actually checked the relay itself. I'll have to look for the proper section in the manual for how to test it. I got the fuel filter, distributor cap, and rotor but it's threatening rain right now so I'll have to wait until tomorrow to replace parts.

optimusprime m1

OVP can be checked in the manual . But pull it out and give it a shake.If it rattles it will need the same work as you did on the other relay [ re heat the joints ].When you bridged the fuel relay ,did the fuel run all the time or did the fuel stop .It should run all the time . Alittle job you can do is clean the rotary idle actuator ..It sits under the airfilter so remove it .It will have a plug on the rear ,and its held in with a rubber and metal strap. It also as 2 rubber tubes coming from it one goes under the inlet manifold the other on is down there some place .Thes tubes do perish and crack.The rotary idle actuator or idle actuator as soma call it will need cleaning out with white spirits of carb cleaner. Spray it in and shake it till all the black crap comes out .Dont dump it in a tub ,it as electrical parts inside. This is something that will help if it is not the problem.Next while filter is off spray the throttel plate with carb and intake cleaner around the top of throttel plate while you just push it down just enought to get crap of the top .It will then close and open cleanly.. Bet it starts with the new rotor arm!

RKramkowski

I changed the distributor and rotor and it now runs. The posts were pretty corroded and burnt. I'm surprised that this is what caused the car to just stop running with absolutely no warning. I've worked on cars for over 40 years (mostly American) and generally either the car would progressively run more and more rough or gas mileage would go down. There were no warning signs whatsoever. I replaced the plug wires while I was at it but what's the trick to getting the wires to lie in the channel so I can snap the cover back on? At the front of the engine, it seems there's more wire than there is space!

Thanks for all your help!

optimusprime m1

RK just as i said in last post .Well you on the road again now. Good you have it fixed .The plug leeds are a pain to get back in place .Start with the shortest one first at the no 1 plug,fit it in to the channel. It is a pain but you will do it. While the filters off give the throttle plate a clean with intake and carb cleaner.. And also that air control valve .The little pipe that plugs in to the z shaped hose from the air filter box dont forget to put it back on .It pushes in to the z shaped pipe . Good luck on glad to help you.

RKramkowski

Yep, I cleaned everything out. And replaced the fuel filter. I found an easy way to get the wires in-place. My engine is extremely clean, almost looks new so it isn't coated with grease or oil. So I started with number one, and taped it down in the channel with a strip of packing tape. I repeated with cylinders 2 - 6, making sure the wires lay flat and used packing tape over each to hold them in-place. Once done, I started with the back and pressed the cover over the posts, working toward the front, peeling the tape off each as I reached it. I had all the wires in-place, with the cover on, in less than ten minutes!

optimusprime m1

RK your engine bay is a bit like mine.