[Hoygaard]

Do you have a LED voltage tester? Using one you should be able to see if the ECU is sending out grounding signals to the coils or not. That way you can tell if its the coilpacks or the output stage in the ECU. I havent got the 155 manual with me at the moment so I can't tell you which wires to check.

 

[mxer125]

Sound's like an eleccy prob to me??? Have you a spare spark plug??(saves you wipping one out) And ground the plug (Engine) turn it over to see if there's a spark on all leads, If there's not?? Could be "a" bad/faulty earth on the connections on the coil packs???.....Good luck and Hope it's something simple

 

[Guest]

Thank you both, will try all!
Regards
D

 

[Guest]

Help!!! The ecu had some faults which are now cleared, have replaced the coil packs and ignition leads and still cant get no:2 and 3 pots to fire????any suggestion? where is the ecu as car is with Motorzone in Limerick and have sourced a scrap car as a potential donor
regards
Dax

 

[Hoygaard]

Having had a look at the manual, it's seems the old twinny also has ignition amplifiers, that's good news; that means that the ECU is not likely to have blown. With a digital OHM meter check for continuity between the amplifiers and the coilpacks and that there is 12 volt present;

Check for voltage at pin 2 of both coilpacks (green-black wires)

Then Check the amplifier to coilpack connections;
Coil1; Amplifier1

pin 3 and pin 1, white
pin 1 and pin 6, white

Coil2; amplifier 2;

pin 3 and pin 1, yellow
pin 1 and pin 6, yellow

Then check for continuity between amplifiers and control unit;

Amplifier; control unit;

Amplifier 1;
pin 7 and pin 24, orange-white
pin 2 and pin 51, yellow-lightblue

Amplifier 2;
pin 7 and pin 52, pink-white
pin 2 and pin 25, green gray

If this also seems okay, get out the LED continuity check lamp from the toolbox and check the wires above with the engine running:

Connect the clip of the LED test lamp to the battery and check that the LED flashes in sync with the engine revolutions. Check the amplifiers first, then the coil packs. If there's no flashing at the amplifiers, the ECU is busted, if theres no flashing at the coilpacks, the amplifier is kaput. (My money is on either a loose connection or an amplifier).

I hope this helps
-- Hoygaard

 

[Guest]

Hoygaard,Thank you!!

 

[ally]

Yeh, that info should trace the fault- I'd also go for a amplifier.
Out of interest, the coil on no 1 cyl does the power plugs on 1 & 4.
The coil on no 2 does power plugs on 2 & 3.
The coil on no 3 does the emissions plugs on 2 & 3.
The coil on no 4 does the emissions plugs on 1 & 4.

 

[Guest]

Thank you all!! Hoygaard and Alley were corect, The Plug lead on No:1 pot was defective, overloaded system which took out the amplifiers.
to cut a long story short, I now own 2 '95' Alfa 155's Found the donor not 5 miles from me!
Now!! to find out what else works on the Donor that can be used in the future will be quite fun!
regards
dax

 

[Hoygaard]