Change fuse #6.....................................

__________________
A Dalton

DIS > Distributorless Ignition System (as you informed us in your first post!)

Ok will do.

The car has the early diagnostic system, OBD1??? would it reveal any useful info?

It might

Pin 8 would be ign codes.

That requires you built a simple led tool.

E320 16 PIN DTC Charts inc. pin 8, pin 14

Is the ovp a NEW one ?????

__________________
A Dalton

Yes brand new OVP from Mercedes - £87.

I will build the tool, I am on a work trip right now around Europe so will get to it when I get back and try to get the car going.

Yes there is 11.10v at each coil LT wire.

I guess the battery is a little low. I know modern cars can be quite fussy if the battery drops slightly but I don't believe this would be one of those...

I'm trying to build the code reader tool however there is nowhere in my part of London to get a simple LED - all smaller hobby stores and ironmongers have closed.

Ok code reader built but something is not right, I used the wiring diagram below.

The LED is on all the time. I thought it may be an issue with the switch so I took it out the loop but the LED is still lit all the time, when the switch is closed it becomes brighter.


I used this info from another post:

"To read codes, plug black lead into Pin 1 (ground), plug red lead into Pin 16 (12v), plug test lead into Pin 8 or 14.

Turn ignition on, press switch 2-4 secs, and count the number of flashes. After reading that code, press 2-4 seconds to read the next code, and continue iterating until all codes are read. You'll know all codes are read when you read the first code again. One flash means there are no codes to read."



Can anyone tell me what I may be doing wrong? I read some information about resistors, would I need one?

Not sure why you're wasting your time with building a blinkenlight to test for codes, a lack of spark isn't going to set a code, and any codes you do get are extremely unlikely to help you troubleshoot further. If you're using a standard LED in your blinkenlight test lead, you do need a resistor. A 5KΩ should be sufficient. Make sure you have the LED in the correct way around, the cathode (short lead, or flattened side) should be pointing towards the black lead.

1995 is a model affected by the biodegradable wiring harness, it hasn't been mentioned ANYWHERE in this thread....have you replaced the upper engine wiring harness, or are you still running the OEM one? If you're running OEM, I'd start by pulling back the sheaths on the wiring bundles and looking for split or missing insulation before proceeding any further.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Well Arthur Dalton said I may get something out of the blink codes, and I do trust him.

This is a 1993 car and much of the wiring was replaced a few years back, from a manual inspection it looks ok.

As there is LT voltage to the coils and assuming the new crankshaft sensor is ok, what else could I test for? Is there a way to test the camshaft sensor?

The OBD1 system in the W124 is more focused on tuning issues related to emissions and general drivability. It is far less detailed than OBDII or anything modern. Lack of spark is an extremely basic problem, unlikely to set a code of any meaningful value. The spark is crank triggered, so a working CPS narrows down to being a wiring fault or ECU problem.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

As well as the lack of spark there is no momentary fuel pump sound when the ignition switches on, as previously mentioned the pumps do work when the fuel pump relay was bridged and the relay was changed.

The ECU has been swapped out for another I had. Someone mentioned the camshaft sensor, is this not also required for a spark?

Solve one problem at at time.

The fuel pumps should run for a "purge" when the key is turned. They don't need any sensors for that. Since you aren't even getting that, you have a more basic problem somewhere.

The spark is triggered from the crank position sensor. The camshaft sensor is for the EFI vehicles to tell the ECU which stroke it's on. The spark is a wasted-spark setup, it doesn't care what stroke the engine is on, it's going to spark at TDC whether it's compression or exhaust.

Start with the fuel pump relay. You already said you replaced it, but no change. Get a copy of the wiring diagram for your car and focus on that one circuit. Start at the relay and work your way backwards. Find out why it isn't receiving a "run" signal and you may solve all of your problems if they're related. Pulling codes and throwing parts at a problem while running around flailing arms in the air will never fix the root cause of the problem.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

I understand your point, I can use a multimeter, however I have been looking at the various wiring diagrams out there and understanding them is something I cannot do. I will need to find the answer in a more basic way.