I am still fiddling with my 500SEL to make it a daily driver.
The list of problems is still long even after I was solving some of the problems. The car was starting to be drivable for short distances, but still overheating (after changing the visco fan, thermostat, cleaned radiator etc)
With these problems I was installing a new water pump (what a pain job if you are not aware that you have to remove the front of the engine and pull the damper and crank shaft pulley).
And after changing the water pump the car would not start while before the car started very well.

I think I put everything back orderly and with the crankshaft mark at TDC cams cylinder 1 are pointing both upward, as they should (Micky Mouse ears). Distributor arm is pointing to cylinder 1 firing...so this should work.

Not starting could be fuel or ignition related.

Fuel pump is running if I pull the fuel pump relay and bridge the 2 terminal in the fuse box (30-battery plus and 87). But I don't know if it is running when I crank the engine... I am assuming it does. After cranking it smells like gasoline.

I was then installing the spark tester and there was no spark.

So what could that be?
I have not changed anything with regards to the ignition. The green cable is installed correctly

Why is there no spark?
How can I tackle the transistor ignition in order to get closer to the problem?
Is there something simple that I am overseeing?

Martin

w:

1) Check the continuity of the pick-up coil/"green" lead. Unplug from the EZL, ohmmeter leads to center pin & shell of connector. 600 (+/- 100) ohms.

2) Check that the distributor rotor is turning when engine is cranked.

Frank,

* The unplugged green wire (unplugged from EZL) has about 600 Ohm
* Distributor rotor is moving correctly

Is there an input signal from the crank shaft to the ignition that could fail and thus no start?

Martin

w:

In that system there is no crankshaft trigger; it is in the distributor (green wire).

Thanks Frank,
I found a wiring diagram for the car, trying to read through it.
Could the switch box TSZ 8z be bad? (the ignition box # 0025452632 on the left side where the green cable to the distributor plugs in).

So far I can find no reason why the ignition should not work but still no start.

I'll probably go back to the beginning.

- Test fuel pressures (system pressure ) and check if the fuel pump is running during cranking. Fuel pump is running if I bypass sockets 87/30 when relay is removed)
- Test for spark again.

I could start the engine, finally.

I removed the distributor and the Green Cable and I fear I have a bad contact between the two or between the Green Cable and the EZL
I had installed a new URO green cable which is bad quality in my opinion but I did not see an alternative on the market and the MB cable is NLA.

I think this green cable can cause a lot of problems if it does not function correctly.

I found this confirming problems with this URO green cable:

www.benzworld.org/threads/380sl-cranks-b...start.3053962/page-3

www.benzworld.org/threads/380sl-green-ig...-euro-parts.3004579/


If there is no connection between EZL (switch box) and distributor there will be no spark. Question is: Will the fuel pump still pump fuel or does the missing pulse cut off the fuel pump at the same time?

Martin

on the us cars, the ezl sends a td signal to the tach and fuel pump relay. euros, can't say but don't think it's different. no td from ezl, no fuel pump, no leaking fuel when stalled and open fuel lines from accident.

porkface,
that makes sense and is confirming what I thought the fuel pump relay is doing.
thanks, Martin