Author Topic: 147 GTA Engine stalled and refuse to restart  (Read 621 times)

0 Members and 1 Guest are viewing this topic.

danielfung2580

  • Newbie
  • *
  • Posts: 2
147 GTA Engine stalled and refuse to restart
« on: June 16, 2019, 09:41:15 PM »
Hi Guys, I would like the share this experience and see have anyone ran into this problem before too.
I was driving my 147 GTA on Saturday afternoon near st.peters, I went to a petrol station to check my tires.
after I got out, I gave it a go in 1st gear and it the engine hesitated around 3000 rmp.
I soon come up to a red light so I put the car into neutral and prepared to stop for the lights.
My engine stalled right after I put it to neutral, I quickly tried to restarted it but I refused to turn over!

At first, the key warning message saying "Immoiliz failure".the car can crank but will not start up.
I was able to get the warning message away my locking and unlock the vehicle,and disconnect and reconnect the ECU plug to ECU,
but the car still refuse to turn over.
the car cranked fine but will not turn over.
there was half amount of fuel in the car, coolant was at 90 degrees C.
I've tried for 25 minutes to restart the vehicle and finally, suddenly I came back to life.
I've drove the car for another 5 minutes to Tempe and found parking
I tried to restart the car for a few times and it start up normally every time.
the engine did not hesitate during that time and rev up normally.
no warning light on the dash.

Has anyone ran into this situation before?
any suggestion on where i can look into this matter?

Mick A

  • Hero Member
  • *****
  • Posts: 707
  • AROCA Member #: 3488
Re: 147 GTA Engine stalled and refuse to restart
« Reply #1 on: June 16, 2019, 11:16:26 PM »
Hi Daniel,

Your description is very good and due to that I am able to give you a pretty confident diagnosis that it will be a faulty Crank Angle Sensor. Of course having not seen the car this is only an educated guess, but I'm pretty sure I'm right.

These sensors tell the engine computer the speed of the engine (sometimes called RPM sensor). The computer can then generate spark, injector pulse, adjust timing etc to run the engine.

When the CAS fails, the computer has no reference, therefore cannot fire the coils, or injectors etc.

They usually fail due to heat, when you switch off the engine, it actually gets hotter before it cools (this is called heat-soak).

The sensors usually work again after the engine cools, but once they get the heat in them again they fail. The car will crank, but there is no ignition pulse without the sensor.

I suggest you contact your nearest specialist and they will easily be able to have the car repaired the same day for you.

Cheers.

Mick.

bazzbazz

  • Hero Member
  • *****
  • Posts: 1485
    • ON THE SPOT ALFA
  • AROCA Member #: 870
Re: 147 GTA Engine stalled and refuse to restart
« Reply #2 on: June 17, 2019, 10:35:32 AM »
Hopefully Mick is correct and it's just the crank angle sensor, and with everything you described I would normally agree with him 100%, except for the mention of the Immobilizer Light.

Faulty Crank Angle Sensor will not cause this to illuminate! Also the fact that you stated the only way you could get the light to switch off was to disconnect the engine ECU again points to an immobilizer issue.

I have personally come across this fault before with a clients 147 GTA, the problem being connections to the body computer as this is where the immobilizer circuit is contained. When trying to start, the Immobilizer interrogates the chip in the key, if it recognizes the chip the immobilizer sends a "GO" command to the engine ECU allowing it to start. If there is a screw up anywhere along this chain the car won't start and you'll get the "Immobilizer Failure" light and the ECU withholds firing signals to the coils and injectors, just as a faulty Crank Angle Sensor would.

The client involved was stranded like yourself and multiple tries at starting over a 30 min period did get him started and home again, but it continued to happen randomly.

The earlier motherboards of the Body Computer were a little fragile and could develop faults while the later units were a little more robust. If the issue happens again you should disconnect the battery and remove, clean and refit the connections to the fuse box under the drivers side dash and the connections to the ECU.

DON'T FORGET TO DISCONNECT THE BATTERY FIRST.

However, as Mick quite correctly said, if you get the same situation happening but without the Immobilizer light, then it's the crank angle sensor.

But lets all hope it just never happens again and you get to enjoy your GTA in peace.  :)

ON THE SPOT ALFA
Mobile Alfa Romeo & Fiat Diagnostic/Repair/Maintenance & Servicing
Brisbane & Gold Coast

2004 Alfa 156 2.0 JTS Sportwagon (Patty)
2000 Alfa 156 2.0 TS Selespeed with Sports Pack
(Eibach 2.5 Lowering Springs)
(Bilstein Sports Dampers )

Mick A

  • Hero Member
  • *****
  • Posts: 707
  • AROCA Member #: 3488
Re: 147 GTA Engine stalled and refuse to restart
« Reply #3 on: June 17, 2019, 11:01:17 PM »
That is a really, really good point Bazz I overlooked that one!

danielfung2580

  • Newbie
  • *
  • Posts: 2
Re: 147 GTA Engine stalled and refuse to restart
« Reply #4 on: June 21, 2019, 05:11:33 PM »
Thank you for the suggestions guys,

I will source a crank angle sensor soon and clean the terminals.
hopefully it will clear the issues.

thanks once again