long-gone-think you were right being something else because I had mentioned that there was a leak on to the crank shaft postion sensor-dh jenkins had mentioned that unless there was a crack there should no effect. There is in fact a crack so much so that I feel I could easily snap the line/wire-feels very, very brittle. It lies directly below were a bit of coolant spilled when I changed the coolant sensor just before the spark plugs then no start. What do you guys think?

If it's cracked, it's probably bad. The CPS is a hall-effect sensor, and reacts to tabs on the crank to get the timing signal. The slightest change in the distance between the sensor and the tab can screw up the signal, and any liquid inside the sensor will more than likely corrode the windings.

Congrats - I believe you just solved your no-start issue.

__________________
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.

I may have spoke too soon. that wire does not appear to be the connection of the CPS. I did spill some coolant but another tech said the same as you with regard to spillage-very difficult to upset that connection although I read that is a possibility of a no-start if is disconnected/damaged. Thanks.

I thought you said there was a crack in the sensor itself, not the wiring...

__________________
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.

to be honest, at this point i dont know where the connection for the CPS is-there was a cracked wire right behind the oil filter and down a bit but thats does not look like the plug of the CPS I saw on the net. I am about to pull my coil to make sure there is spark there. Do you or anyone here know if I buy an in line tester for the spark plugs how useful that test is. Will it only tell me i have spark? Or will it give me an idea of the strength?

I read where someone had a 190e-same year-had spark, timing was right, had fuel, etc and it turned out to be a bad ignition module or whatever the coil plugs into is named. Perhaps that is very rare.

Read my post on the 1st page about spark testers. They are useful in determining spark, but it takes a timing light to determine if it's sparking at the right time.

Ignition module is the correct part, and they do go bad; like any part. Of course, a bad ground could cause all your problems as well. People always forget about grounds... Voltage to the part is useless if it can't get to ground and complete the circuit.

At this point, I'd take it to an indy - they'll have the necessary tools to verify everything at once in less than an hour so you can replace the correct part and be done with it.

To be honest, unless you have the correct tools to check & verify things, all the FSM's, guides & advice in world can only lead you to an educated guess. As I've stated before, I've seen countless people spend many hours and hundreds of dollars replacing parts on the advice of others before coming to me (or my shop), only to find that the correct repair cost less than 1/4 of what they spent on their goose chase. An hour of 'real' diagnostic time performed by a 'real' tech with 'real' tools is worth more than you know.

__________________
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.

Dh Jenkins-I will reread what you say about plug testers. Its very hard to argue with your advice and experience about going to an indy for the repair.

I tested for spark which I have from the coil. I was going to pull the fuel relay and then spray ether and then i think thats it for me. May also pull the rotor cap to see if the rotor spins and somone said something about it possibly breaking from the bracket but still spinning.

The only other things is I had to hammer (a bit) this metal tab thing to unscew the coolant sensor-silver with a round hole. It started right away though. It was only after changing the spark plugs it would not start.

Ok, it took me long enough to locate this thread again, but read it and see if it helps your situation.
1990 190E no start

Ok will read that-thanks for helping!

ok, no problem
cheers!

I read the thread that ismalley just suggested to read. This is all quite interesting. If it has spark, at the right time, and compression (even low) and you shoot ether in the intake it should at least try to start.

I don't know where he hooked the timing light on the wires. Presumably it was an induction type light and he had it looped over wire #1 just before it went to the plug.
On the M103, the wires run together through the plastic housing that snaps into the valve cover. Except #1, which only briefly passes through the corner of it. What if the wires are worn out and the remaining 5 wires that are all in contact with one another were arcing across to each other and wreaking havoc with the firing order.
Individually they may seem to be intermittently sparking but perhaps somewhat randomly, except #1 which could be unaffected. Although in that thread I think he mentioned he had all the wires out and saw them sparking in sequence. Just grasping here!

One time on my M103 I gave it a tune up and it wouldn't start afterwards. I finally figured out the when I replaced the cap I unknowingly knocked the carbon tip off the spring on the center electrode. I had to put the one off the old cap in it and it started right up. Another time (an American car) I had a new cap & rotor but of different manufacture. The car started but had a wandering miss. I got a matching rotor and it went away.

I have now disconnected the fuel pump relay to keep this bare bones and the can of ether! Some of the spark plugs I actually broke not using a spark plug wrench so that was pretty stupid however the car did not start with old plugs re-installed that did not appear damaged. I follow your point on the timing of spark with fuel(this case my can of ether) Will let you know the results. I have been advised against the platinums(plugs) but the local shop here only sells those and that was what was in the car for years so it should fire at the very least IMHO. Thanks for all the input.

Possible other issues-clogged exhaust, crankshaft position sensor, vaccum leak, and a member mentioned bad ground as a possibility. After checking timing, thats it for me if it does not fire.

Try getting the H9DC0 spark plugs from the dealer or send me a pm with your personal email and I will send you the online company I use that has OEM parts for a fraction of the cost. It does not make any sense to do a tune up and continue using the old wires and spark plugs....but the spark plugs are not really that expensive...under $6 at the dealer. Keep us posted on this.

Actually, at least the Bosh wires are designed to clip on to the knobs and not the bare threads. I wasted some time when I first acquired my 300E because I thought it was like my old Audi [which did have wires that attached to the threads]. Perhaps the [more expensive] Beru wires still use the bare threads.

Guys-i got the car to fire by disconnecting the fuel relay to only have a can of ether as my fuel-if there is any lesson here is reduce the car to the basics with no input from the computer sensors-probably very obvious to most here on this forum.

I had been trying to richen up my fuel air/mix with a new coolant sensor(car running) that was off and I believe it would not re-start due to too much fuel which I wrongly connected to the spark plug job that followed. When I put the computer back into the equation and reconnected the EHA it continued to run but when I went to put it in gear it stalled and would only start again if I disconnected the EHA.

Thanks to everyone who chimed in-I have certainly learned alot from everyone so I feel the problem was a blessing in disguise!!