Engine Stalls at any speed
 

My 1985 190E 2.3 8vlv has developed a serious problem.

The engine will stall on me at any speed, not while coming to a stop, not while coasting in idle, just any speed, even on the highway when doing 120kmph it will stall.

I'm not sure what it could be but I is rather dangerous to drive the car like this and I would like to get it fixed.

Once it does stall, it won't start up again until a few minutes pass, I think the engine gets flooded, or something, but that's what happens everytime. After a few minutes pass, it will start right up and keep on going like nothing ever happened.

The only notification I get of the engine dying is that when I step on the gas, there is no response at all, all the gauges work like they are supposed to, and once the car stops and rpms drop to zero, then all the dash lights come on.

Could it be that the ignition coil is overheating? It is quite old, but I'm not sure if I can test this or not. It seems to me like there is no spark being produced, and the engine cuts, but the tranny keeps it spinning which is why there is no indication, is that even possible?

This problem has me really worried...
Someone help :(

xp

i would check out the usual suspects first,#

coil

rotor

distributor cap,

spark plug leads.

spark plugs.

loose connections-at the coil and battery.

fuel faults such as fuel pump relay,fuel filter,fuel pump.

Of the above mentioned items, I would forget the plugs, wires, cap and rotor for causing the failure mode you describe. As for loose connections, since you are a DIY, put rechecking everything you have done recently at the top of the list.

Steve

Sounds like a fuel related issue to me...

I would suspect a fuel pump relay is going bad, or perhaps even the fuel pump itself. Has your fuel pump been louder than usual recently?

coil???
 

Thanx for the input guys, I guess I should have mentioned that
the distributor cap, rotor arm, wires, and plugs are all new, less then 3 months on them.

Fuel pump works fine, no buzzing sounds, as well as fuel pump relay is also in order, I rebuilt it.

I'm guessing that it could be the coil. I drove a bit, and when I touched it, it was warm, I did not get a chance to check if it's hot after the car dies, but I was told that this might very well be it, does anyone have any tips on how to check it? Signs of the coil going bad?

Is there a way I can check if there is a spark? that would tell me a great deal of info.

I will be redoing the wireing harness myself since the cost for a bunch of wires is ridiculous, and I can't even afford it, I guess it's gotta be an electrical issue.

It's also completely random.

xp

This happened to a friend of mine recently. After checking all the usual suspects and a few more it turned out to be the fuel pump itself.

my car is a 124, 230E, M102 which basically has the same engine as xp190. I just had my fuel pump replaced last Saturday. As a matter of experience, failing electric fuel pumps does not really stall the vehicle. It becomes loud over time and your car will suddenly develop a hiccup one day. The vehicle will sort of jerk while accelerating at any given gear change jsut like what happened to me.

My mechanic checked electricity, cleansed the plugs and changed fuel filter with no positive effect. Changed the fuel pump whose sound changed from a loud buzzzz to a whine and everything is fine now even better I suppose since it has become more responsive.

just my 2 cents.

crank sensor
 

I don't know 190's, but many MB's have a crank sensor (electromagnetic sensor at the flywheel attached to a wire) which sends a signal to the car's control system. Our 124 had a similar problem, where the engine would just die, anywhere, anytime, very random, and start back up easily. It never died for long, sometimes only for a fraction of a second, sometimes for a couple. EXTREMELY nerve-racking on the highway!
It turned out the sensor had frayed insulation and a poor connection at the bellhousing. Replaced it (about $100) and the problem went away.

It is easy (on the 124 anyway) to replace, if you can locate it.
Good luck.

201s have that same sensor, I'm leaning toward wireing for two reasons

1. it is worn like no tomorrow, I already replaced a few wires and connections, but there is still many to replace.

2. it all started happening after I washed the car, so it's possible water is stuck somewhere on a wire causing a short which does this.

I plan to take apart all the thick plastic insulation and replace it with my own, and at the same time fix any suspicious looking wires.

Just gotta go to a junk yard strip a few more MBs of all their wires so I can color match then together :)

xp

I fixed up the crank sensor, but just now coming back the car died on the higway again doing 120kmph

I really don't know what could be causing this

coil does not heat up, seems to be warm but working fine, all the other parts are good, I have no idea what could be causing this and I really need some help, it's not safe driving like this, but I don't have much choice.

xp

might want to check your overvoltage protection relay.
early models gave problems.

OVP relay would not cause the engine to cut out at highway speeds on that model. Just rough idling, bad starting, poor fuel economy and the ABS light.

Xp: does you rpm goes erratic? Drops and picks up again? From what I read it doesn't but just wanna get it confirmed by you.

The reason I'm asking is because I have been experiencing the same thing. I my opion my fuel pump has developed more noise but this is only based on my own ears.

My car won't stall because it picks up again and run well. I can hear a pop from the cat as engine picks up again put I think this is because unburned fuel. I believe my problem is somewhere in the ignition system.
On the other hand i know the fuel relay need td signal to keep the pump running.

Where is the crank sensor located? Is it the one located below distributor near timing scale?

Question to all: From where do the rpm gauge get it's signal? From the ignition module itself or is it split up from somewhere else?

I hope I don't make this worse for you, xp.

190Dee as always thanks for the help, thanx to everyone for help

This problem is killing me, I have no idea where it is originating from.

To answer some questions

No, rpm gauge behaves normally other then that it drops off slowly until I reach a speed slow enough for it to hit zero.

This is what happened last night. I was cruising at 120kmph, changing lanes, let off the accelerator or hold it won't make a difference, all of a sudden I feel that the car is not gaining speed but losing it, speed and rpm starts dropping, if I put the car in neutral as it is still rolling, the rpm will drop to 0 and all the dash lights go on.

For some reason, the engine is still spins well after it dies, but the car is rolling, is this because the tranny transfers power to the crankshaft? I don't know if this is possible with automatics.

Last night fortunately I was just near a ramp and got off and pulled to the side of the road, left the car off for a few minutes.

I restarted it and with a bit more cranking then usual it started right up and did not cause problems any more, but, knowing that this will happen makes the car not safe to drive.

Could this be related to the voltage regulator on the alternator?
I see my broken oil level indicator dim and light up when I hit the breake, is this normal?

190Dee the crank sensor is the one by the scale, you have it right on.

I know this has nothing to do with OVP because my car can run without any electronics at all, just not as good.

I'm really clueless and need your help with this guys.

Can a short in the ignition module cause this?

How can I test anything to get any clue as to what happens?

TIA

xp

Correction
 

A correction to what I said eariler

There is apparently two crank sensors, one at the front, and one at the back.

The smaller one at the front goes directly to the diagnostic port, the one at the back goes from the flywheel to the ignition module.

Mine is worn and it's possible the wire is broken somewhere along the way. As soon as I have a chance I will pull it out and examine it.

A new one is $134 at Fastlane. I always wondered where that wire goes... now I have an idea.

xp