Just broke down in an intersection
 

One of the worst places to break down, especially when you're in the innermost lane and no one is cutting you a break to push it off the road!

Anywho, so started my w124 up this morning and all seemed right in the world, my SRS light came on which has been happening a lot lately and when it goes out it gives just a half of a second jump in RPM's which I thought was weird but nothing seemed wrong so I was like "w/e".

Well I was sitting at the red light and it was idling just fine, then, it kind of rumbled...then it rumbled hard and went back to normal, at this point I knew something might be wrong, then it rumbled hard and the RPM's drop and felt like it was going to die so I put it in neutral and it went back up but then started doing the same thing and finally died out. Started it and it fired up but then just died out again. Started once more and got the RPM's up and held it at 30 for a bit and then it died again as soon as I let go of the accelerator. When I try and start it now, it cranks and tried to catch but it misses and it misses hard.

Someone pulled over behind me and helped me push her off the street into a parking lot so I'm kind of just chillin letting her cool down to see if that will help. I don't really know where to start looking for the problem and I'm hoping to at least get her working to drive her back home since I'm REALLY CLOSE like less then three minutes and I'm out of AAA tows -.- and info/advice would be greatly appreciated!!!

Thank god there is a whataburger in this parking lot! Lol

Will it idle at all in park? I had a similar issue recently, I replaced the leaking breather hose to the VC/intake and it helped (engine was running lean) but I'm not sure it was the root cause. Mine would idle in park but stall as soon as it was put in drive or reverse. Either way, good luck man!

Check the OVP fuse, and listen for the fuel pump when you turn the key, first 2 places to start.

Thanks for the reply, I couldn't get it to start back up, let it sit in the parking lot for a little bit and and she started back up and is idling fine in park and drive. I'm wondering if it may be a clogged fuel filter. Pumps are hissing and working as they should (as far as I know lol)

Get behind your battery and wiggle / press in your fuel pump relays. Both mine and my daugter's w124 did this and hasn't happened since. Both would just shut off and sometimes start right back up. Hers finally didn't and I did the same thing to her car and has been fine since.

My money is on the crank sensor, based on the "catch & fail" starting behavior you described.

I bet it was hot when the car stalled and cooler when it restarted. The sensor cable behind the bell housing is probably frayed.

Thanks for the replies, I'm starting to think it maybe a computer malfunction?

My SRS light would randomly come on and then turn off but I didn't think anything of it, well it's been popping on a lot and when it comes on it makes my ABS light flash for a split second, then when the light decides to go out I get (as mentioned before) a small sudden jump in RPM's :/

Now I've i've been driving it to work and back and all around and it hasn't done it again but every time I get to a red light, I'm kinda just waiting for it to happen again, cause it was just so random the first time!

There could be so many things wrong.... I was really looking at the engine bay today and after a year of having this car with the excellent service it's provided I'm seeing decayed wires, vacuum lines that are just left hanging with no sight of where they go, weather'd components and I looked at my MAS computer which looks like it's been messed with before by the previous owner with some type of adhesive holding the casing to the actual computer.

It's pretty much like "where do I start?"

Start with the battery, and the voltage regulator on the alternator.

The SRS/ABS lights indicate a low voltage condition. When voltage becomes too low the car shuts those peripheral electrical systems down.

Frayed wires + summer heat + engine bay heat = electrical gremlins. But I doubt things are anywhere near as bad as you are probably imagining them to be. Just start with the obvious items first -- including the aforementioned crank sensor.

I had the problem and it was the crank sensor...

overheating spark plugs?
 

I was checking out the crank sensors today and poking around in the engine bay, and I noticed my spark plugs wires, they were really bad when we got the car I mean you could see the sparks at night because they were so worn, so when I replaced them last july I couldn't figure out how to get them back on the nice little set up they were in so I kind of left them hanging there, they were good for the longest time so I didn't think twice. Well when I was checking them out they are pretty much touching the exhaust manifold and there are rubbing marks from one that was laying on it. Could this have been my culprit? It kind of makes sense that letting the car cool down before it would start again but I mean it still could be the crank sensor and I haven't tested it yet, so we'll have to see. But does this sound like it could be a culprit? I mean they've been like that since July. :confused:

Very well could be. I had a similar issue and changing the plug wires fixed it. It's very rarely the CPS.

DMC-12, from my experience it would be physically impossible for any of the spark plug wires to reach the exhaust manifold, presuming you purchased the correct replacement spark wires. The spark plug wires should be routed in the recess of the valve cover to the distributor cap. After they are neatly in place a cover hides the ignition wires so they are not visible and nowhere near the exhaust manifold. Please show a picture of the spark plug wires on your engine.

Also, any disconnected vacuum lines should be reconnected and replaced if they are cracked and brittle.

At this point it would seem preferable to take your 1991 260E to a reputable, MB-trained indie for a professional diagnosis and repair.

Thank you for the reply, well when I replaced them awhile ago, I did mean to put them back in the neat way on the valve cover they're supposed to go, but I just couldn't get them to go back correctly so I left it off and below is the result.

[IMG]http://i902.photobucket.com/albums/a...E/photo-13.jpg[/IMG]

[IMG]http://i902.photobucket.com/albums/a...E/photo-12.jpg[/IMG]

[IMG]http://i902.photobucket.com/albums/a...s%20300E/j.jpg[/IMG]

That's exactly how mine looked. I used a metal clip with the new wires to hold it up to the vacuum line near the red tube / egr valve.

DMC-12, your spark plug wire routing begs for trouble. It looks like a partially completed installation. I would never operate an engine with spark plug wires positioned that way. MB must make some brackets/clips that support the spark plug wires so they stay clear of the exhaust manifold.

I'm familiar with the 104 engines where the spark plug wires are concealed inside the valve cover.