BurnsSide42

I have a 95' MB E-320 convertible I am looking at.
Car has a crank - no start problem.
Car has NO SPARK- No Fuel Pressure
Cranks over beautifully with good compression.
Battery Voltage to coils at Key On Engine Off - and Key On Engine Cranking. (less 1-4V while cranking)
Checked over ALL ceramic fuses - rolled them etc.
Found a melted 30AMP fuse under windshield driver side (blue relay) in the screwed on cover relay box. (Replaced it no change)
This is a 1995 so it has 3 coils for all 6 cylinders - it does not have a distributor setup. Also does not have the EZL (?) module for the CPS
I am still working on locating the CPS to OHM it out etc. (This would be good to know where it is as well - I am told it's on the driver side of the bell housing near the oil filter housing.... I can't see anything back there lol)
No change in Neutral either - I see many of you mention this as a possible cause - the NSS (not this case).
Crankshaft Position Sensor has been ordered (BOSCH)
Any and all professional help appreciated. THANK YOU

Floobydust

First and foremost, have you checked the date code on the engine wiring harness? If you still have the dreaded ecco junk harness, all bets are off until it is replaced. The date needs to be 1998 or later (date code on harness near the ECU/battery).

If that has been addressed, beside the CPS, a problem with the Over Voltage Protection relay will also cause a crank, but no spark, no fuel problem on a '95 HFM system. Have you checked the fuse(s) on the OVP itself? Have you replaced the OVP? It has been my observation that the OVP fails more often than the CPS.

BurnsSide42

As per the harness - I have not check it for date code yet - was not aware there was an official issue with them. Coming from Swedish cars I am used to fixing wire harness rot problems (rebuilding an entire wire harness) but the German's love to make everything 10X more complicated then needed so I am sure a replacement would be more logical. It does have wires starting to crumble - but I have not found/seen any I would call very bad yet. That said I have check the fuse in the OVP relay and it was OK - I have wiggled the relay itself with no change. I guess I'll get a new one coming to swap out. Owner has a 1994 E320 as well - but there are things that are different on that engine it seems so I do not know if they are exactly compatible for parts swapping/diag. I'd rather fit new parts in place of known faulty ones at the very least in efforts to fix it's overall issue.
Thank You Floobydust! I will update as I replace/find things.

Floobydust

Check the insulation near the temp sensors or the MAF where the individual conductors are visible. If there is crumbling such that the copper wire is visible at these points, you most likely have an old ecco junk harness.

BurnsSide42

The car is a 1995 - the harness tag on the ECU says 1993. Yes there is wire coating crumbling on about 4 wires at the bulkhead above the oil filter housing. They ahve been re-covered with electrical tape - everything else looks fine so far. As I said I have a CPS arriving today which I believe will get the car started. Beyond that the owner will have to decide what they want to do. Again - they have an entire 1994 E320 "parts car" which they could use - but seemingly there are enough items different around the engine bay so that may not be an option.
Will keep updating as work is done/repairs are made!

Floobydust

The engine harness for a later production 1995 will be different from that from a 1994 so the parts car may not be helpful. The temperature sensor connections will be different.

BurnsSide42

Well new BOSCH crank sensor is in. No change - found corrosion on pin 1 of the OVR - going to see about getting one. ECU connectors looked clean too - but there is water collecting under the ECU for sure....
I would wager that IF the relay changes nothing - the harness COULD be the culprit.

Floobydust

Unfortunately, it wouldn't be the first time, and certainly it won't be the last time that a degraded ecco junk harness has caused a no-start condition.

BurnsSide42

Success! It was the Overload Protection Relay! Fired right up.
I have also located a few 2001+ build date second hand harnesses which I am going to advise the owner to pick-up to have ready.
So 1 more fixed! He is going to bring me his other one to figure out the convertible top that does not work. Pump runs - no top movement.... Stay tuned for the next thread!

Floobydust

Excellent! Glad it's up and running!