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Misfiring issue with 159 3.2

595 Views 5 Replies 4 Participants Last post by  LarsMW
Just seeking any advice or input. I had another misfire and check engine light flash yesterday when starting the car after a hot night and pushing her a little bit. Drove well the night and days prior but when I started her up to go to work it started fine, then began vibrating and then came the check engine light flashing before each settled. I'm especially concerned and anxious as I just had this issue a couple of months ago and spent close to a grand fixing it. This happened in September where upon accelerating the engine misfired and would start shaky after. Codes P0300, P0302, P0301 were produced at the shop. An extensive clean up ensued with new spark plugs, engine flush, all coil packs, and ignition coil and gasket fitted. Spent 1700 with that and some other things so you could understand my displease when I was greeted with yet another flashing engine light. I took it for a drive after and it seemed O.K. I believe it will come back though because I Don't know the issue in the first place as lots of engine components were just reffited brand new. Could this be a one time sorta thing because of the hot night and pushing it then the morning start? A benign cause? Or is it more indicative of something more serious and ... expensive. If this is going to happen again what could really be causing this? Any Input would be a great read.
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Which diagnostic tool was it? It needs to be MES or AlfaOBD, or you can apparently get completely wrong codes. At least when it comes to misfire on the JTS engine. Generic diagnostics tools like Torque etc can’t extract the cause of the misfire and just shows codes for misfire, when it could in fact be caused by things like a faulty throttle body, over/under pressure in the intake manifold etc etc.
 

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Get a proper diagnostic done with appropriate Alfa specific software. While doing so check the high pressure fuel pump readings and make sure the "Fuel Pressure Measured" follows the "Fuel Pressure Calculated". The high pressure pump in these engine tend to fail and will cause misfires. If the two readings follow each other then look elsewhere.

Just thought i'd mention this just so you don't go down any dark rabbit holes tearing the engine apart chasing phantoms.
 

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My problems were fuel delivery.
The fuel pressure sensor was WAY off and indicated 6000 rpm with just the igniton on. I got a new one and at the same time had full service on all my injectors. Now it purrs like a kitten :)
 
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