is there a easy way to tell if your computer control module or your ignition control module is any good with just a VOM?

did u check spark and fuel delivery ?

yes I have teched every sensor in this rig, ignition element , fuel delivery system, and they all seem to be in operational, yet the damn thing will not start or even give me the notion that it wants to start...I am following the MB prescribed diagnostic protocol now its time to get serious and find out if the CIS-E is bad or the Ignition control module is bad...my guess is that we have a bad timing element...but which? thats why I need to know how or if its possible to check the ignition control module and or the cis-e with limited equipment......... is there a way!

I had similar problems on my C36 M104 engine. The biggest problem for me was that the start/stall problem was intermittent. I think humidity was a factor.

1.The crank position reference sensor (CPS) OR the wiring to the CPS can cause this problem. The wiring was cooked by engine heat and the insulation had turned to dry dust (MB bio-degradable wiring indeed!). I used the MB "repair solution" for the wiring. Later I changed the whole engine wire harness.

2. The final fix was to replaced one of the three ignition coils. Would you believe that it was the last of the three coils to be changed! The removed bad coil looked absolutely perfect and testing with a multimeter revealed nothing.

My car has run perfectly ever since.

Good luck with the 190!

thanks oz I will take another look at the crank position sensor....maybe even take it out for a visual inspection!!

My advice is related to the C36 M104 Engine in the W202 and will not be directly applicable to your car. However all Mercs were designed by Merc and carry the family genes!

You could try change the CPS Sensor with a known good one.

The next thing I would try is to change the coil with a known good one. (I have three coils in my engine and had to change one at a time).

Multimeter circuit testing the wiring from the controller computer to the CPS did not indicate any anomalies. This testing certainly didn't indicate the major breakdown of the insulation in the wiring to the CPS connector. But I do know that if I gently and cyclically tugged on the CPS wire that the engine would quit. The only other way I know to check the insulation is to cut open the coaxial wiring and thereby potentially destroying it. I am not sure if your car preceded the years involved with the Merc wiring debacle.

The Mercedes wiring repair solution for my W202 is actually called a Camshaft Connector in the EPS (both the camshaft and crankshaft use the same part number). The part number is A129 540 22 81 (the same as the number marked on the end of the connector body).

Testing the CPS wiring:


The embarrassment of Mercedes Green-friendly bio-degradable wiring (circa 1992-1996).
The green powder and silver flakes are the remnants of the internal coaxial wire insulation:


The Mercedes wiring repair solution for either the Camshaft or the Crankshaft Position Reference Sensor Connectors:

Have you tried starter fluid? You should get a brief stumble with this. If not and you are definite about your spark then probably you're not getting enough air into the system.

It's also possible that you have a very big vacuum leak. In this scenario, the leak can keep the fuel meter flap from going down thus starving the engine of fuel.

Take your pick and try it out. And please just bump this thread next time so viewers can follow your diagnostics.

thanks bpaz h i will put that in the pool of reasonable things to try .....this thing does not have very many vacuum line and I have recheck all of them...u see I am very use to working on older Hondas that are a vacuum nightmare to say the least. This MB only has about 10 vacuum lines that I have found and they all seem to be connected.....I have noticed that the original line is very brittle .....most likely from heat.....I will however do a complete inspection of all lines and connections as well as components and search for strange goings on..


Ps. I have tried ether and still nothing

thanks OZ thats the next thing to get a good inspection.....then its the vacuum lines

I try to send some pix so you can see what I am seeing

Have you checked the resistance of the Crankshaft Position Sensor. It should read between 680-1200 ohms across the center pin and outer shield in the connector cable at the Ignition Control Module.

The position sensor is installed on the crankcase above the starter flange. When the engine is rotating, an alternating voltage is produced in the position sensor as a result of induction. 1.5v is produced at starter speed and as the engine speed increases, the voltage rises to approx. 3v.

If the Ignition Control Module does not receive a signal from the Crankshaft Position Sensor, the ignition system is inoperative.

So, if you are getting good spark on the spark plugs, then I would think that your Ignition Control Module is ok. If not, then check the Crankshaft Position Sensor or the Coil.

__________________

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

Hi slk... nice to hear from you again...I am get the proper resistance it read about 950ohms
but in the diagnostic protocol it say with the ignition on I should get a voltage reading of greater than or equal to 1 volt and I got 4.7 volts at the ignition control module ...it also says that I should have a insulation reading of less than or equal to 200 kohms....well I get no reading at all it just stays at 1

dwell angle was 3.6 which is low at start it should read 9-49 degrees
although the dwell may be x10 I'll have to read the tester book

190:
I also have a 190e only its the 2.3-16. Currently it is also doing a similiar thing yours is doing. If you try starting the car for the first time in any day does it fire right up idle normally then shut off then when you try to restart it it just cranks and cranks? Mine wont make it on the road right now, hehe...
I bought a new coil and have yet to install it and see if it is the coil making it do this. Would Autolite spark plugs cause a coil to burn out? Current coil is within all resistance specs though.

If you have OE spark plug wires, I would use Bosch non-resistor spark plugs. They're getting harder to find, but they are available.
I've tried Platinum, but the non-resistor type work better.

__________________

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

I changed the plug the last time slk suggested that to me to a Bosch plug and then check the firing which seems fine yet the damn thing will fire yet no combustion in the cylinder

what is failing us here? ....it looks like the the ignition control mod is fine ....moving on.

let me know how the coil works out for you...
I am a Honda man too ........rebuilt many a Honda oldie...wow is this thing not mechanic freindly