Hi guys, I hate to become a member of this board because of a no start problem, it seems like thats how it always happens.

I just recently bought a non running 190E 2.6 sedan. I really dont know the circumstances leading to it not running, but i took a chance.

It will crank over fine, but it wont start.

Ive checked the following:
It has blue spark- it seemed rather inconsistent on two cylinders though.

It has great compression- 140+/- in each hole.

It has fuel pressure up to the fuel distributor, I can also hear the pump cycling like its supposed to. -however, I opened the line at an injector and it wasnt much more than a trickle?

Ive replaced cap/rotor/wires/plugs.

Ive checked for TDC, even cycled the wires all the way around the cap to advance timing.

Ive shot ether into the intake, no luck.

only glimmer of hope came when I was advancing the timing, and i had #1 in the #5 position. while cranking it, a small bit of smoke came from the tailpipe indicating detonation.

given the slightly irradic timing, Im curious if this might be a crank sensor?

I'd appreciate your thoughts on this thing.

Im really curious about the starting fluid thing. if it has spark, then why wouldn't it try to fire when I sprayed ether down the intake?

If it was a 350 it would've been running a long time ago....

When you replaced the cap & wires, did you match the order they were in, or did you consult a manual? What did the old plugs look like?

A blue spark isn't quite as useful an indicator of adequate firing voltage as you might think - the initial voltage required to bridge the gap while firing is far higher when the plug is under compression. I'd use an actual spark tester connected in-line w/ the wire & plug - especially if you've got weak sparks on other cylinders.

If it won't run on starting fluid, that sort of (but not completely) rules out a fuel delivery problem. Did you check timing with a timing light? Have you checked for vacuum leaks and checked the airflow sensor? Have you taken any vacuum gauge readings?

Did you get any sort of history from the previous owner about how it "died"?

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A.S.E Tech A1,A6,A7,A8 & MVAC 609 + EPA 608

Unless stated otherwise, any question I ask is about my greymarket 1985 380SEL.

thanks for the reply, Dhj. I did make sure the wires were in the correct order- #1 at 1oclock etc.

im pretty limited on diagnosis tools where i am, ive got an ohmmeter, a comp tester, and basic hand tools.

I actually swapped out the coil with a new bosch unit to see if that helped, still no change.

i havent checked for vacuum leaks, nor have i checked the airflow sensor. how do you go about checking that?

I was told that the car ran fine until it just quit.
I really didnt put much stock into his evaluation.

My impression of the guy was it could have been sputtering for 6 months and it would be "running fine" as long as it ran.

You can get a used timing light on ebay for around $20-$30 bucks. It's a decent investment for older cars.

A cheap vacuum gauge you can pick up almost anywhere that sells automotive tools for around $15.

I've you've got a new coil, you probably can do without the spark tester.

You might try unplugging a few things and trying to start it, especially since you don't have many tools. If a particular sensor is causing problems/shorted/etc..., some cars will run if it's simply disconnected (may not work with MB's).

Is the check engine light on?

__________________
A.S.E Tech A1,A6,A7,A8 & MVAC 609 + EPA 608

Unless stated otherwise, any question I ask is about my greymarket 1985 380SEL.

correct me if im wrong, but there isnt much need to check timing with a light if ive already confirmed TDC right?

check engine light: I couldnt tell ya; ive never had it running. all lights come on when key is in on position.

something I didnt note: the plugs I used are bosch supers, they are copper core which means less resistance in the plug. the old plugs looked to me like platinum plugs, but none were fouled out when I replaced them.

All an engine needs to run is fuel, air and a spark.

The timing light will give you a good idea of the existance of spark.

Having it run well is what the other stuff is for.

Clean plugs are essential for reasonable detonation. Pull at least three of them and make sure they're clean and dry. A little brushing with a brash bristle brush and simple green does wonders.

Thx -CTH

__________________
- cth350@gmail.com
http://www.111lakeside.com/

as stated, I have spark. timing is on, i checked TDC (TDC= Top Dead Center)
Ive pulled the plugs one by one and checked each cylinder for spark, and its there. They are new plugs, installed them yesterday. when i pulled them , they were clean, and smelled of gas so i know its getting fuel. Ive hit the intake with ether, so it should have fired if it was a fuel issue.

at one point, I had all the plugs attached to their respective wires, just laying in the plug hole. As it turned over, i saw each cylinder detonate 1-5-3-6-2-4. it almost seems they don't detonate in the chamber?

Could this be a plugged cat issue?

Have you checked the Crankshaft Position Sensor?
Mine reads 814 ohms cold and 900 ohms hot.

For voltage, it reads .842 v ac cold and .986 v. ac hot. You'll need someone to crank the engine for the voltage test.

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

Slk, thanks for the reply. do you know what the symptoms of a bad crank sensor would be? I'll check it with my ohmmeter. Im only able to get the cold reading, as it obviously wont start.

on the 2.6, is it located under the oil filter?

i had the same exact problem with my 1989 190e witch is the exact same car.... here is a cheap and easy way...that car is befor the obd sensor so go to pep boys with 20 dollars ask for a gm universal coil replace your old one with the gm......... and presso it will start and replace the crank sensor which is underneath the oil filter get one from the junk yard and test it with an oms metter it must read .700 or higher .... replace it and badda bing badda bomb the **** will start TRUST ME!!!


GM HELPING THE MERCEDES WORLD RUN!!!!!!!!!!!!!!!!

Weak spark, or no spark. One end connects to the Ignition Control Module that is mounted on the driver's side wheel well and the other end goes behind the oil filter at the flywheel.
Disconnect it at the ICM to check your measurements.

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1993 190E 2.3
2001 SLK230
1971 LS5 (454) Corvette Convertible

Confirming TDC only means that the #1 cylinder is at TDC when the crank mark is at zero; that's not going to give you any information at all about when the spark plug is actually firing on that cylinder, hence the timing light. Did you at least confirm that the rotor in the distributor was pointing at #1 spark plug when you were at TDC on the compression/power stroke? That'll get you close, but even a 1/4" twist of the cap can change timing by 5 degrees or so.

Have you verified that the rotor is even spinning?

__________________
A.S.E Tech A1,A6,A7,A8 & MVAC 609 + EPA 608

Unless stated otherwise, any question I ask is about my greymarket 1985 380SEL.

ok, mine reads at 794 ohms cold. when cranking the engine, the voltage is VERY spiradic, reading anywhere in the low teens to mid 40's.

and thanks for that photo, it was very helpful!

Voltage should be sporadic. It's a square wave form best viewed with an oscilloscope.

When you say mid 40's, do you mean 40 volts or .40 volts? Do you have your meter set on AC or DC?

__________________
A.S.E Tech A1,A6,A7,A8 & MVAC 609 + EPA 608

Unless stated otherwise, any question I ask is about my greymarket 1985 380SEL.