2019 Maserati Ghibli, P0299-00, P0300, P0301-303. Low power under high load.

Hello,
2016 Maserati Ghibli. New in stock vehicle. Low power under high load. 3.0 liter bi-turbo. Sets P0299-00, P0300, P0301-303. Bank 1 turbo assembly has been replaced, had other faults for wastegate control issues. Anti-rattle clip on wastegate actuator rod was improperly positioned, binding the rod movement. That issue is repaired. I have attached a screenshot of both banks lambda values when issue occurs. Bank 1 lambda goes well above 1 (3-7 roughly) when low power concern is happening. Bank 2 stays near lambda 1. Lift throttle lambda values track together around 15 (Injector shut-off I presume. I suspect an fuel delivery issue on bank 1 only, perhaps an ECM injector bump-up voltage supply issue, or an injector rail restriction, or even possibly a complete incorrect injector rail w/injectors on bank 1. Has single high pressure pump, with manifold to deliver fuel to each rail through individual pipes to each rail. Pressure sensor at end of rail for bank 1. P0299-00 is for Underboost.

Looking for any input prior to deeper testing, specifically any suggestions for the least invasive way to potentially verify a low fuel delivery issue to bank 1 under high load/rpm conditions. I have a Pico scope available.

you have a MDEVO??? how do you have this scan tool??

also,, i would suspect faulty waste gate actuators.

check spark plugs, are they clean and torqued properly.

check low side fuel pressure?? whats the reading when koeo?? and reading after a hour ??

We are a dealer, so yes we have an MDEVO. I am ruling out fuel pressure issues based on Bank 2 running well (based on Lambda values) and Requested/Actual fuel rail pressures tracking together well. Rail pressure sensor is located at the end of the Bank 1 rail facing the firewall. If it were a low pressure fault (or high pressure fault), it should affect both banks equally. I am still leaning towards either an ECM injector voltage supply issue for Bank 1, or some type of issue with the Bank 1 injectors themselves. Maserati only sells the injectors as a complete assembly with the rail per bank. There are several versions of this engine worldwide, so it could be and incorrect injector/rail assembly. May get time to get the Pico on it this week to look at injector patterns bank to bank for comparison.

generally if you have a fuel issue, a fuel code will come up.

you said you replaced a turbo?? and this car is under warranty?? did your tech support system authorize it??

again, I suspect waste gate actuators.

Bank 1 turbo was replaced with BOL (tech support) blessing. Once old turbo was off the vehicle it was found that the anti-rattle clip at the wastegate actuator rod was out of position slightly and causing that connection at the rod to the wastegate lever to bind. Original codes were P2261-00, and P25B3-00, both related to wastegate malfunctions. New turbo went on, those codes did not reset afterwards. Only codes as described in post title are setting now. If the airflow was low due to a turbo (or both) under-performing, I would expect a rich (less than 1) Lambda value, and this system does not use air flow meters.

I understand now,,, ok.... so to be clear, the low boost code is the only code you have left?? and its for the ( bank 1 ) right side of engine

I still suspect a faulty waste gate valve,

also, these turbos waste gates work different. the waste gate is normally open all the time, then when you want to build boost. the waste gates start to close to build boost ( opposite of how waste gates normally work on older cars )

so at idle everything is fine.. but when you start to get on the engine for power a little, the waste gate will then start to close, in order to build boost. hence the low boost code because the waste gate is sticking open.

I would suggest swapping the pop off valve, on the turbo, and also checking with a vacuum gauge by the waste gate solenoid on top of the engine intake manifold, apply vacuum and make sure both waste gate rods move properly. and they hold vacuum since they are t-d off

Actually the under-boost code is not bank specific and there is no Maserati provided info for the code. We had already checked the wastegate control vacuum system previously with no faults found. We had also checked the diverter (Pop-off) valves with an MDEVO activation. Additionally the bank 1 turbo we replaced included a new diverter valve. For what it is worth the turbo outputs are combined after the intercoolers though a y-pipe into a single throttle body. Boost sensors before and after the throttle body, so no direct way to diag a bank specific boost issue that I am aware of by the ECM. Plugs and coils were also moved around bank to bank. My theory is that the excessively lean mixture under high load is reducing the exhaust flow/pressure enough to be lowering total boost pressure, hence the misfires and under-boost code. The next planned step is to look at #1 and #6 injector patterns for possible voltage supply and/or pulse width differences. If no issues found, then intake comes off to get a look at the injectors themselves and /or the rail or High Pressure supply manifold that takes the pump output and sends it to the rails indiviudally. I misspoke on one important detail, the rail pressure sensor is actually on the Bank 2 rail, NOT Bank 1. Hoping to narrow this down as much as possible given the information we have versus loading the parts gun......

hmmm. i do know that maserati has had issues with their fuel injectors. staying open is a issue, oil will smell like gas..

also, issues with their low pressure, and high pressure fuel pump.

have you by any change hooked up a generic scan tool and looked at fuel trims??

So got Pico hooked up to injectors #1 and #6 (one from each bank), got a capture while low power issue happening. It seems that the #1 injector is not even being activated (same pattern on both + and - terminals at ECM). Have not yet tried the other 2 injectors on Bank 1, but suspect they may be the same, so the whole bank 1 may not be injecting any fuel when this happens. Will be verify ing ECM powers and grounds as well.

if that is true,, then you do you have misfire fault codes??

what fault codes are present right now??

using a generic scan tool, what are the fuel trims??

Yes we do get all bank 1 cylinder misfire codes. Have not yet tried a generic scan tool. I have a Snap-On Verdict, but last updated in 2011, but it should have an OBD2 mode, will see if we can get it hooked up soon. This is an in-stock vehicle and low on the priority pole at the moment. Also forgot to mention the scope patterns are with all channels connected through 20:1 attenuators just to be safe.

ok, possible fuel injectors faulty, but looking at your scope pattern, i am wondering if the ECM is actually activating the injectors. it looks like it not??

question for BOL guys. what do they think of the scope pattern, is the ECM grounding ( activating ) the injectors, or if they injectors is not firing, does the ECM shut down that injector for safety reasons??

looks like your only getting about 3 volts to the injectors. can you retest power side of injector with scope negative to battery negative & then test injector negative side with scope positive to battery positive. I'm assuming these injectors are ground side controlled from pcm? Is injector voltage 12 volt ? I have no acess to maserati information. Possible electrical fault to injectors ?

Maybe load test wiring to injectors on problem bank?

Using 20:1 attenuators, multiply scope reading times 20. Direct injected piezo injectors. ECM bumps voltage up to approx. 65 volts.

these are not piezo injectors.. they are solenoid type injectors. however the voltage is spiked up depending upon situations.

note.... info, about injectors.

Ahhh. Makes sense. Sorry for my lack of knowledge on that

Thanks for posting the injector information tech25

Tech25,
Yes indeed you are correct, NOT piezo. Just finished looking through my Ghibli intro book as well looking for any details I might have missed regarding the fuel and engine control systems. Made an assumption based on other reading, and I was WRONG. I assume you are a Maserati dealer tech as well? Would you care to have a phone conversation about this vehicle?

hey there, we can talk about it if you want. PM me your phone number and best time to call...