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after some small diagnostics at fuel tank pump area, car doesn't start.
no spark. all basics check fine.
i'm suspecting I fried the IGNITION E.C.U.
IS THERE A BASIC CHECK TO BE DONE TO THE ECU'S?
any help is greatly appreciated.
thanks, Charlie.
there are two pickup sensors on the passenger side of the tranny front housing. you can check them.or just change them.the car WILL START.forget the ecu.
 

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he has renewed the two flywheel sensors
 

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after some small diagnostics at fuel tank pump area, car doesn't start.
no spark. all basics check fine.
i'm suspecting I fried the IGNITION E.C.U.
IS THERE A BASIC CHECK TO BE DONE TO THE ECU'S?
any help is greatly appreciated.
thanks, Charlie.
There a possible fix for this. I just have to find my notes from Alfa tech training class 30 years ago.

Give me a few days.

Let me know if you have already fixed it.
 

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Ask "Eric" (This forums moderator) your models "Papajams" wiring diagram. I looked at mine and I saw there's no direct communication from trunk wires to the ignition ECU.
1609363


Here's the 2 relay link
1609364


Will she run on "Starter fluid"?..if so that would move me way from the electrical side to the fuel side...if not, the stay on E- side, I like the crank sensor idea (there's an ohm test procedure on the BB) or the "lost magnet" theory! Maybe someone can post how to verify the magnets are there/correct?
 

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its not only the ohms test on the flywheel sensors, but there is a volts test too.
the volts test will show if a signal is being generated (ok, best would be a scope, but not many of us have a scope!)

Certainly on the S4 (with its single crank sensor) this test is valid, and I almost bet it is the same for the twin S3 sensors.

You measure between the middle pin and one of the outer pins of the connector, whilst cranking the engine (one outer pin will show nothing, the other will, so try both to be sure)

iirc it should be about 1.5V with your trusty meter set to Volts AC (not DC) and cranking the starter over.
iirc. use same pins as the ohms test, photo:

flywheel sensor terminals.JPG
 

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I have been troubleshooting this same problem for a while now. Attached are pics of what I think is the magnet on the flywheel viewed through the position sensor port. You can see the hex nut at the base (8mm), so it can be replaced. When I put something ferrous on it there is no magnetic attraction. Looked around at Alfa supply vendors and cannot find one. I have ohmed the sensors and they both check out in the 800-1250 range. I bought one sensor and replaced them one at a time, did not help, maybe both are bad. I have not tried the voltage test discussed above so I will try that today.


1609424
1609425
 

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When I put something ferrous on it there is no magnetic attraction. Looked around at Alfa supply vendors and cannot find one. I have ohmed the sensors and they both check out in the 800-1250 range. I bought one sensor and replaced them one at a time, did not help
just a question, if they ohmed out, why did you replace them?
did you (or were they in the first place) connected to the correct plugs: grey to lower sensor / black to upper sensor?

I doubt they are magnetic. It is just a raised reference point.
 

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Got these results: New Sensor 993 ohms, 0,75 Volts on same 2 pins used for resistance reading, 0.28 on other 2 pins
Old Sensor 1 1005 Ohms, 1.0 volts on same 2 pins for resistance, 0.365 volts on other 2 pins
Old Sensor 2 992 ohms, 0,8 volts, 0.26
Not the 1.5 V stated above but what I would call in family. Only bought one because in another thread someone replaced a ECU and it did not fix the problem and then they replaced both sensors which did fix the problem so I was shooting craps. While ohming and verifying that the sensors were connected to the correct connector like you say above, I discovered that the lower sensor connected to grey had a broken connector so that was another reason to order at least one sensor.
 

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Have you checked or replaced the main fuel injection relay? It is the big relay mounted next to the ECM. I've replaced 3 on Bosch spiders that sat a long time in the last 2 years. There is also a small power relay next to it you should check for 12v out with key on. Follow the wiring diagram for wires to test. Bad ECM would be rare.
 
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