I never realised how hard it is to update your own thread when you haven’t been on for a while lol!!!
I had hoped to have updated sooner but I trapped a nerve in my lower back which has been very painful and stopped from working for the last few weeks.
Anyway here is a progress report on what I have found so far after a fair amount of research and before you ask, No it is still not running!!!
This car is fitted with the short lived Telefunken TSZ1 Ignition Control Unit and its ancillaries which shares its system with the older 323i and some early 5 series.
I found some extra information that was very useful so I hope it helps anyone else with a similar problem.
So from the BMW 3 SERIES 1985 E30 Haynes Owner's Manual I found in Chapter 5 Engine Electrical Systems I found a set of tests for this Unit.
In photo 10.2b you can see the numbers of the connections which may vary from car to car so here is another photo that may help.
I have now done these tests a couple of times and here are my results
1I rechecked for spark on 3 different plugs all ok
2 Retested Coil and checked wires. Rechecked the readings with a multimeter with the following results
+ to centre Post of 7.69 ohms
-to centre post 7.69 ohms
+to – minus = 1.0 ohms
Next test i did was on the 2 pin Impulse Generator Plug that comes from the distributer and plugs into the Ignition Control Unit.
The multimeter readings between + and – are:
Ignition off I get 1.064 ohms
With ignition on and cranking I get 2 to 3 volts and over difficult to read on your own lol.
On the ICU socket side I get 79.5 ohms between+ and – .
Testing the Round Plug from the engine side with a multimeter
From the Haynes photo
6 (31) to 2 (16) = 11.85 volts
6 (31) to 3 (15) = 11.80 volts
6 (31) to T/D = 2.680 volts
6 (31) to 5 (S) = 53 plus volts (weird reading).
Testing the TSZ1 Ignition Control Unit Mounted on the Bulkhead with a multimeter.
Tested for continuity between the round plug and the ICU on the bulkhead
6 (31) to 31 (6) Ignition Off = 7.5ohms (0.1volt)
(3) 15 to (3) 15 Ignition On = 0.0 ohms (11.11 volts)
(2) 16 to (2) 16 Ignition On = 0/L ohms sometimes I get 0.0 ohms tends to flick between the two
(2) 16 to (2) 16 Ignition Off = 0/L ohms sometimes I get 0.0 ohms tends to flick between the two
T/D to T/D Ignition On = 5.25 ohms
Now at this point I rechecked the coil and even tried another coil but got the same result
To Summarise so far:
As I have mentioned before I am not an electrician but most of the results do correspond to the Haynes Manual.
However wire 16 (2) apart from using a multimeter I also tested it with a Digital Circuit Tester and that showed the power jumping around between 10.5 to 12.5 Volts whereas the my multimeter shows a steady 11.85 Volts
I cannot find a corresponding wiring diagram yet to trace the route but I think it goes direct to the coil?
So the next step is to see where else it connects to?
I have also been told that the Impulse Generator in the dizzy could be the problem but the test results seem to show that it is ok.
As for the ECU I don’t know how to test that and I cannot find any information on how to?
I also don’t know how to remove the wiring harness if I have to and I cannot find any information on that either.
I don’t know if running a direct wire from the battery to the coil would temporarily do the trick and allow the car to run for longer that a minute!! lol
So if anyone else has any advice or has had this issue and knows how to fix it please get it touch.
