Hello Guys,
I am really stumped. I have a 2007 Maserati Quattroporte automatica (ZF transmission) with only 52k miles. I have had misfires on cylinders 1 and 3 since I got the car a month ago. CEL fault codes P0300, P0301, and P0302. I took it to the local Maserati dealership and they have not been able to find a fix. Here is their writeup:
"Had misfire on cyl 1 and cyl 3, disabled injectors on cyl 1 and 3 and could tell a difference in running, swapped coils to cyl 2 and 8. Misfire stayed with cyl 1 and 3. Removed coils and spark plugs, checked plugs, plugs had recently been replaced, antiseize was still wet on the threads. Moved spark plugs to cyl 2 and 8 with coil packs, tested again, misfire was still on cyl 1 and 3. Disabled injectors on 1 and 3 by unplugging, car hesitated when unplugged, unplugged coils on 1 and 3 with running, car also hesitated with unplugged. Checked compression on 1 and 3, was slightly lower than normal but not enough to condemn any other parts. Noticed alternator was new when testing, used throttle plate cleaner and found leak on intake at cyl 3. Removed intake, bolts were way over torqued, taped off all ports, performed leak test, no abnormalities on intake manifold. Found pinched gasket on cyl 3, replaced all gaskets, properly torqued intake and replaced all components, misfire not present, car is running as designed."
That sounded good on paper. However, after driving the car about 15 miles, the CEL came back with the same exact code. Took the car back to the same dealership and this is their second writeup:
" Pulled codes and had codes p0301, 303 and 300. Checked for intake leaks, none found, checked coil an injector connections, all were good. Proceeded to check cam timing with scan tool, reset cam variator timing control. Checked voltage to injectors and used oscilloscope to check injector voltage and firing pattern, checked cylinders 1, 2, 3, 7, 8 and all were firing same pattern and voltage was good. Disconnected battery and performed hard reset, removed coils and plugs from both banks to compare and swap back to original places, used breakout box to check can line going through ecm, all can lines had correct resistance and voltage. After hard reset started vehicle and vehicle ran smooth. Checked misfire counter with scan tool and was reading 0 misfires on cylinders. Checked ground point for injectors and coils, ground point good. If this car had a misfire for an extended period of time and the vacuum leak in the intake that it did, it could overwork the injector driver in the ecm and cause erratic behavior as random misfires. vehicle is running as designed at this time."
After I picked up the car and drove it another 10 miles or so, you guessed it! The same codes came back again, but with one more code that hasn't shown up since: P0430 (catalyst efficiency below threshold bank 2). When I tried to take it back they said it could be the ECM failing.
I had since taken the car to my indy mechanic who has done work on pretty much every import. He swapped parts from another 07 Maserati Automatica I have with 44k miles: mass air flow, spark plugs, coils, etc. He even opened up the valve cover on bank 1 and inspected that side. Checked compression, did a smoke leak test, there are no vacuum leaks. Everything looks good and clean. Car seems a little sluggish when driven. There is no rattling noise coming from the engine.
What else could it be? I am hoping it is not the ECM The maserati dealership don't want to see me anymore, and the other maserati place in town tells me they will not reprogram a used ecm to the car -if that is what ends up to be the problem. They will only reprogram a new ecm, of which there is none in USA or Italy available. Maserati would have to make one to match my specs.
Somebody please help.
I am really stumped. I have a 2007 Maserati Quattroporte automatica (ZF transmission) with only 52k miles. I have had misfires on cylinders 1 and 3 since I got the car a month ago. CEL fault codes P0300, P0301, and P0302. I took it to the local Maserati dealership and they have not been able to find a fix. Here is their writeup:
"Had misfire on cyl 1 and cyl 3, disabled injectors on cyl 1 and 3 and could tell a difference in running, swapped coils to cyl 2 and 8. Misfire stayed with cyl 1 and 3. Removed coils and spark plugs, checked plugs, plugs had recently been replaced, antiseize was still wet on the threads. Moved spark plugs to cyl 2 and 8 with coil packs, tested again, misfire was still on cyl 1 and 3. Disabled injectors on 1 and 3 by unplugging, car hesitated when unplugged, unplugged coils on 1 and 3 with running, car also hesitated with unplugged. Checked compression on 1 and 3, was slightly lower than normal but not enough to condemn any other parts. Noticed alternator was new when testing, used throttle plate cleaner and found leak on intake at cyl 3. Removed intake, bolts were way over torqued, taped off all ports, performed leak test, no abnormalities on intake manifold. Found pinched gasket on cyl 3, replaced all gaskets, properly torqued intake and replaced all components, misfire not present, car is running as designed."
That sounded good on paper. However, after driving the car about 15 miles, the CEL came back with the same exact code. Took the car back to the same dealership and this is their second writeup:
" Pulled codes and had codes p0301, 303 and 300. Checked for intake leaks, none found, checked coil an injector connections, all were good. Proceeded to check cam timing with scan tool, reset cam variator timing control. Checked voltage to injectors and used oscilloscope to check injector voltage and firing pattern, checked cylinders 1, 2, 3, 7, 8 and all were firing same pattern and voltage was good. Disconnected battery and performed hard reset, removed coils and plugs from both banks to compare and swap back to original places, used breakout box to check can line going through ecm, all can lines had correct resistance and voltage. After hard reset started vehicle and vehicle ran smooth. Checked misfire counter with scan tool and was reading 0 misfires on cylinders. Checked ground point for injectors and coils, ground point good. If this car had a misfire for an extended period of time and the vacuum leak in the intake that it did, it could overwork the injector driver in the ecm and cause erratic behavior as random misfires. vehicle is running as designed at this time."
After I picked up the car and drove it another 10 miles or so, you guessed it! The same codes came back again, but with one more code that hasn't shown up since: P0430 (catalyst efficiency below threshold bank 2). When I tried to take it back they said it could be the ECM failing.
I had since taken the car to my indy mechanic who has done work on pretty much every import. He swapped parts from another 07 Maserati Automatica I have with 44k miles: mass air flow, spark plugs, coils, etc. He even opened up the valve cover on bank 1 and inspected that side. Checked compression, did a smoke leak test, there are no vacuum leaks. Everything looks good and clean. Car seems a little sluggish when driven. There is no rattling noise coming from the engine.
What else could it be? I am hoping it is not the ECM The maserati dealership don't want to see me anymore, and the other maserati place in town tells me they will not reprogram a used ecm to the car -if that is what ends up to be the problem. They will only reprogram a new ecm, of which there is none in USA or Italy available. Maserati would have to make one to match my specs.
Somebody please help.
