[Lg54]

You are going down the wrong path...We would normally swap an air mass sensor in this case...They go bad occasionally ...Especially if you use a cotton gauze air filter....Jason

Sounds very logical. I will mention this to the dealer.

I took the car to the dealership but they told me that they did not get this specific code (p2187 p2189) they just got a random misfire one. But looking at the trims, it is obvious that there is a problem there. I tried to get them to look at the live data but for some reason Maserati reader did not have live fuel trims or they don’t know how to look at them.

I got a misfire code too, had the obd reader hooked up and basically Closed Loop fueling failed and open loop took over and fuel trims were not compensating making the car run rough and hesitating.

I am trying to share as much info as posible to see if this issue can be resolved. I have little faith in the dealership, its the only one in the island with little experience. I am very appreciative of the info you are sharing with me, gives me hope. Thanks

 

[Lg54]

Hello guys,

Dealer has basically given up. I am waiting for a new MAF sensor but I believe it is not that.

Check this out
This is the car warmed up short term fuel trim 1 and 2 pegged at +25

This is the voltage at the 02 sensors, seem very lean.

could this mean maybe fuel pump?

had this happen too and the car went nuts

Strange thing is that driving all parameters are fine.

 

[[email protected] Enzo`s Atlanta]

Honestly, fixing something like that via the internet is gonna be extremely difficult..The car needs to be checked for vacuum leaks for starters with a smoke machine....Jason

 

[Lg54]

Honestly, fixing something like that via the internet is gonna be extremely difficult..The car needs to be checked for vacuum leaks for starters with a smoke machine....Jason

Thanks Jason. Yes, I ordered a smoke machine, should be getting it soon. Changed the MAF sensor but the problem persisted. What has me puzzled is that when the fan is off, everything is good, but when the radiators fan kick in, the fuel trims spike to +25.

Could there be an actual vaccum leak and when the fans kick on Idle goes up and vaccum leak opens up?

If there is a vaccum leak i belive it is going to be under the intake manifold or intake manifold gaskets.

 

[Sock Tucker]

Thanks Jason. Yes, I ordered a smoke machine, should be getting it soon. Changed the MAF sensor but the problem persisted. What has me puzzled is that when the fan is off, everything is good, but when the radiators fan kick in, the fuel trims spike to +25.

Could there be an actual vaccum leak and when the fans kick on Idle goes up and vaccum leak opens up?

If there is a vaccum leak i belive it is going to be under the intake manifold or intake manifold gaskets.

you can also run it, spray starer fluid along the vacuum lines and see if it revs up. If it does, that's where the leak is.

 

[Lg54]

you can also run it, spray starer fluid along the vacuum lines and see if it revs up. If it does, that's where the leak is.

I have done this already, no luck. Hopefully the smoke will reveal something..

Can someone recommend a fuel gauge that connects to the fittings on the fuel rails?

 

[2fromtheCouve]

I would assume the dealer checked your fuel pressure and alternator output while the issue is happening??

 

[Lg54]

I would assume the dealer checked your fuel pressure and alternator output while the issue is happening??

Not sure, they basically gave up. They where using Maserati’s Diagnosi system, which they said they could not see live data.

 

[Lg54]

Ok guys. I removed my air filter box lid and replaced the air filter which was very dirty. While I was at it, I cleaned the throttle body with a rag and carb cleaner. When I put it all back together it worked a lot better. now when the fans turn on, fuel trims do not get altered as much. It Doesn’t makes sense but I have to keep monitoring it, I might have solved the issue.

 

[Lg54]

ok so I was checking alternator charging volts. I have a Black Decker battery charger that checks if the alternator is good or not (not actual voltage). Under normal load, headlights and radio, alternator is good. When the fans turn on, or I put the A/C in full blast (turns fans on) the alternator checks out not good.
I read the instructions on the battery charger and it states that when checking alternator, A/C must be off. Is this why I am getting a fault when fans are on? What is the acceptable output of the alternator with the fans on? This so I can test actual voltage with a multimeter.

EDIT:

I checked voltage at battery at idle RPM:

Normal accesories on: 13.6v

A/C full blast: 13.4V

Cooling fan on: 13.4V

Based on another post i found, these are acceptable numbers. I have kept monitoring the fuel trims and they are doing good.

 

[Rennz]

Like I said before, I'm no Mas expert. But in my experience, 13.5V is the min acceptable output voltage for an alternator 13.5-14.5, you should also monitor the amp output with the voltage. And given:

• The problem occurs only at idle (low RPM)
• Only when the fans turn on (high amp draw)
• No issues at speed (higher RPM/alt speed)

I think this is a charging/pwr system issue; could be:

• loose or corroded ground
• the alternator is getting weak
• corrosion inside a battery cable or wire

Also you cleaned the intake and changed a "very very" dirty filter. This may have allowed the engine to idle just few RPM higher, spinning the alt..... But hey, in the end its you who needs to make a decision on how to get this fixed and share it with us because the theories can go on forever.

 

[[email protected] Enzo`s Atlanta]

No offense, but why does this look like guided diagnostic via the internet? I agree with wanting to check the charging system, but you reference in another internet post about charging numbers? How do you know that person isn't a moron? I'm not sure your issue with your car, but I would be careful not to throw parts at a car based on stuff you read on the internet including from me...I can't see what you have going on, so it hard to say...J

 

[Lg54]

No offense, but why does this look like guided diagnostic via the internet? I agree with wanting to check the charging system, but you reference in another internet post about charging numbers? How do you know that person isn't a moron? I'm not sure your issue with your car, but I would be careful not to throw parts at a car based on stuff you read on the internet including from me...I can't see what you have going on, so it hard to say...J

Well the reference I used for charging numbers was written by you on another post, they do make sense. Do you happen to have actual alternator output numbers based on the service manual?

 

[Lg54]

Like I said before, I'm no Mas expert. But in my experience, 13.5V is the min acceptable output voltage for an alternator 13.5-14.5, you should also monitor the amp output with the voltage. And given:

• The problem occurs only at idle (low RPM)
• Only when the fans turn on (high amp draw)
• No issues at speed (higher RPM/alt speed)

I think this is a charging/pwr system issue; could be:

• loose or corroded ground
• the alternator is getting weak
• corrosion inside a battery cable or wire

Also you cleaned the intake and changed a "very very" dirty filter. This may have allowed the engine to idle just few RPM higher, spinning the alt..... But hey, in the end its you who needs to make a decision on how to get this fixed and share it with us because the theories can go on forever.

Thanks for the input, sounds very logical. If the problem comes back, this would be the first things i check.

As I mentioned, after air filter change and TB cleaning the problem basically went away. It doesn’t make sense for me but 🤷🏻‍♂️

 

[Lg54]

Well the reference I used for charging numbers was written by you on another post, they do make sense. Do you happen to have actual numbers for alternator output based on service manual?

 

[Rennz]

So.. Just for kicks and out of pure curiosity, I went and checked the charging voltage of my battery at idle ('10 Cabrio):

• Engine cold, high idle, most accessories off the voltage was 14.38V
• Engine cold, a/c on full with max fan speed it was 14.25V
• After a drive with the engine hot, low idle speed, and the cooling fans on and a/c on full it was 13.74V
• Warm, low idle, fans off it was 13.84V

 

[Lg54]

So.. Just for kicks and out of pure curiosity, I went and checked the charging voltage of my battery at idle ('10 Cabrio):

• Engine cold, high idle, most accessories off the voltage was 14.38V
• Engine cold, a/c on full with max fan speed it was 14.25V
• After a drive with the engine hot, low idle speed, and the cooling fans on and a/c on full it was 13.74V
• Warm, low idle, fans off it was 13.84V

Thanks for the info. Mine is Hot low idle AC On full 13.4V. Could 0.3V be considered that my alternator is on the way out? Don't know. Anyways, thanks for the info.

 

[Rennz]

Thanks for the info. Mine is Hot low idle AC On full 13.4V. Could 0.3V be considered that my alternator is on the way out? Don't know. Anyways, thanks for the info.

Who knows for sure without putting hands on it. These are all just opinions/suggestions trying to help with limited information and give you, hopefully, some ideas to take to your shop or mechanic in order to form a plan of attack.

 

[Lg54]

Who knows for sure without putting hands on it. These are all just opinions/suggestions trying to help with limited information and give you, hopefully, some ideas to take to your shop or mechanic in order to form a plan of attack.

Thanks man. As of now the car is working as it should. Hoping it stays that way.