04' 156 JTS Troubles

[shitsngiggles]

Hi all,

I am new to the forum and Alfa's.  I have just picked up a rather tidy 2004 156 2.0 JTS (manual), lovely little car that I can't wait to get it back on the road ... yes I brought a lemon with the intention of fixing for my son as a 17th birthday present.

I am a diesel fitter by trade so intend on doing what repairs I can myself, but still happy to resort to a recognised Alfa workshop for specialist work/tools etc, I have checked the the car over and no major mechanical issues are apparent, just some ECU/Sensor faults or issues that make it difficult to start and idle rough, otherwise seems to drive just fine.

So ... Using Multiecuscan I have cleared error codes and immediately got back the following codes:

• P0190 = High Fuel Pressure Sensor
• P0555 = Brake Booster Pressure Sensor
• P0340 = Phase Sensor

So I have been researching and progressively checking the obvious (or not so) dodgy connectors, shorted wires, fuses etc but still no luck, disconnecting the High Fuel pressure sensor showed no difference in code readings leading me to think there is possibly nothing wrong with it and the issues lies else where .... I spoke to a known Alfa workshop in Brisbane, I got the owner who was not helpful at all, he had never heard of "Brake Booster Pressure Sensors" on any Alfa's and basically told me my scan tool was full of crap these cars have no such thing, I shouldn't waste my time and book it in to him for diagnostics at $150 per hr .... Bullocks to him, I was actually looking at the sensor that "doesn't exist"! ... The dude then continued to try to tell me P0340 Phase Sensor was the Cam Variator and he changes them for about $800 parts + labour ... I also already knew that P0340 is the Cam Phase Sensor on front of the exhaust cam, behind the pulley ... Not the Variator! .... needless to say I politely discontinued the conversation and deleted his phone number.

Anyways supporting my thoughts of one fault possibly causing other codes and nothing wrong with the high fuel pressure sensor I have found a thread on a UK forum of someone having similar issues/fault codes and it turned out to be the P0555 - Brake Booster Sensor had faulted and is on a common circuit with the High Fuel Pressure Sensor, as you cannot get to the Brake Booster Sensor without tilting the engine he cut the wires and all other faults cleared and the car started better and ran at full power again, although understandably still with the P0555 - Brake Booster Pressure Sensor fault and check engine - take to dealer warning lights on.

Since checking all fuses and main connections of fuel sensors etc the car now idles even worse, it has started hunting and even does so at revs

Has anyone else experienced similar?

Does any have any suggestion to access or test/check/isolate the Brake Booster Sensor?

Does anyone have a how to guide for tilting the engine so I can gain access to it?

[shitsngiggles]

What ... nothing ... nobody  

This thing is still bugging me, I am convinced it is one single fault on a common circuit as unplugging the problem sensors do not even show as "no signal" on the computer like others do, am starting to think the fault may actually be the cam phase sensor itself I have managed to get it running evenly again ... not sure what happened but it has stopped hunting, still difficult to start and still throwing the same codes, but drivable.

Can anybody recommend a good dealer/workshop Brisbane or north

Also looking for a pair of headlights as they are too perished for normal polishing.

[Mick A]

I would suggest you have an air/vacuum leak from what you've described, not an electrical fault.

[poohbah]

Can't proffer any technical advice, but I would suggest you post your query in the 932 Series section (for 156, 147 models) of the forum - more likely to get a response that way.

[bazzbazz]

Mick is spot on.

I run a Mobile Alfa Romeo Diagnostic and Servicing business here in Brisbane. I have sent you a private message with my contact details should you wish any assistance in tracking down your fault.

Baz

[bazzbazz]

Hi all,

I am new to the forum and Alfa's.  I have just picked up a rather tidy 2004 156 2.0 JTS (manual), lovely little car that I can't wait to get it back on the road ... yes I brought a lemon with the intention of fixing for my son as a 17th birthday present.

Really!  ADOPT ME! 

Baz

[psproule]

Have you tried measuring resistances of these sensors at the ECU pins and checking against factory specs? Check resistance across and resistance to ground in case there has been a short somewhere in the loom. I too would suspect a vacuum leak the way you describe the idle issues. But given it's a JTS (I own one) have you checked out the cam lobes yet for wear? They are prone to wearing them off from oil dilution thanks to the direct injection. And throwing big-end bearings from same. They also clog up inlet manifolds and runners as there isnt the fuel spray to clean them when in operation.

You might find it easier to simply drop the motor out to sort the sensor / harness issues. I can get one out in about 3 hours. Handy for swapping belts and idlers too.

Pat