Slow Throttle and Sluggish Acceleration

[StanleyNii]

Hi guys. I have a 2007 Infiniti M35 which i bought used. When the car is standing still and you step on the accelerator pedal the engine revs does not respond quickly and takes a long time to go up. Also when in gear and you step on the pedal it accelerates very slowly even with the accelerator pressed to the floor and it takes much longer to get to even 4000 rpm. I am clearly outpaced by cars like corollas and most saloon cars.

Kindly help.

Thanks

[TDot]

Welcome to the M35 .

[StanleyNii]

Thanks TDot

[DH3]

Is the check engine light on?

It sounds like it's running in "limp"mode.

On my M45 this just started to occur and it threw codes P1762 and 1752 that have to do with the direct clutch solenoid valve. This triggered the CEL.

I've been clearing the codes with my OBD reader but I plan to get it into the shop soon because it recurs about once a week.

[Cash440]

I also felt this way when I first got my M35x, but I've found that doing all of the basic maintinence greatly improves the car's performance. Good oil, new spark plugs, new differential fluid, new transaxle fluid, and new atf all will greatly help with this. My car also needed the accelerator pedal recall done (you shoud look in to this), as my old pedal was sluggish with delayed response times. However, the new pedal coupled with the new software they updated the computer with feels like I'm driving a totally new car because the power delivery is immediate, and pressing the pedal about halfway down is near full throttle.

[StanleyNii]

Update on what i have been doing so far. I changed the catalytic converters as they were plugged. Changed transmission fluid, changed motor oil, Knock sensor changed, Cleaned a couple of sensors. The car's performance had improved greatly. The car is still a bit slow off the line and slow the respond to gentle pedal input when on the move and when it responds the RPM suddenly jumped up but acceleration does not not correspond to RPM. I am suspecting its the accelerator pedal sensor so I am ordering the whole unit. I got the this persistent diagnostics code (P1148). Also can anyone confirm if the transmission for the M35X is the same as that of the regular M35 and M35 sport or different. Considering replacing the transmission too. Thanks

[BizAsUz]

I have noticed that all cars have that "gear" that will give you the power when you hit the gas.
For the M35 it is SECOND gear... First gear gets you moving (not the best for a power start) but once it switches to second gear and you gas it, it will go....

[StanleyNii]

I know but this is a 3.5L V6 which is also AWD. My 04 maxima takes about 6.5 sec from 0 to 60. This is supposed to be quicker but it takes about 15 seconds from 0 to 60.Clearly this is not right as I burn lots of gas because I need to press more on pedal

[mikew83]

Having owned many Nissan Maxima's, And Infiniti V6's and 8's, I know what you mean! I think the first post really sums it up, welcome to the M35. But yours is definitely far worse than it should be.

When I got mine, I just felt like something was ever so slightly retarding my acceleration. As soon as I had the front and rear differential fluid changed and my trans fluid changed, I noticed a 10,000% difference. I know mine is current on all recalls, so I'm sure the new accelerator pedal plays into that too. Seriously though, you would be shocked how stupid it is that the differential fluid helps the car accelerate. But you have to remember, the clutch to engage the front wheel drive is in the rear differential. So it makes sense. My trans fluid got changed because my trans pan was *almost rusted off of my car, so it had to be done. The M is one particular vehicle where you really NEED to do the maintenance items for it to perform correctly. I wouldn't order a new pedal and sensor if yours hasn't had the recall done. Let Infiniti take care of all of that for you, and diagnose for free what really is going on, if it's something else. But I think someone is on to something with Limp Mode. My I35 did the same thing but never popped a CEL.

[adrdsouza]

I've got a 2007 M45 and i feel the sluggish acceleration too. I've had the car fully serviced with engine and transmission fluids (not sure about differential fluid), spark plugs, the accelerator sensor (the recall part) and even had the engine re built cause it wasn't maintained very well by the previous owner which had caused damage within the engine.
The problem isn't as bad as the first post (Corollas etc cannot get past) but there is a delayed response in pick up. When i step on the gas, it takes a little while to register. I was assuming that this had to do with the ECU tuning and getting an Uprev tune would help. Is that not the case?

[StanleyNii]

How do I get the ECU retuned. I live in Ghana and we do not have infiniti dealerships here like in the US. Most mechanics here are not that good with these cars either. Is it possible to do the ECU retune my self. If so what do I need and how do i get the ECU software.

[BlackCat81]

AWD? If yours is optioned for it, your snow button isn't on, is it? There is also a TCM update which helps, I just did it on my 06. Contrary to what was previously posted, the clutch for the AWD system is not located in the rear differential. Nothing in the rear diff controls any of the AWD functions. Cam position sensors can cause issues if the car is low on oil as the actuators rely on oil pressure to move the VVT, but you'd get a check engine light. Another common symptom of a failed CPS is an extended crank time when starting.

[BlackCat81]

How do I get the ECU retuned. I live in Ghana and we do not have infiniti dealerships here like in the US. Most mechanics here are not that good with these cars either. Is it possible to do the ECU retune my self. If so what do I need and how do i get the ECU software.

TCM/ECM/ any software is only uploadable with Consult software. Nissan may be able to do it.

[mikew83]

Contrary to what was previously posted, the clutch for the AWD system is not located in the rear differential. Nothing in the rear diff controls any of the AWD functions.

BlackCat, I thought it sounded strange myself, but a tech at my local Infiniti dealer and an Indy shop both told me the same thing when I had both F&R diff fluids replaced. They may have been confusing it with the transfer case?

"The ATTESA E-TS version uses a mostly conventional RWD transmission. Drive to the rear wheels is constant via a tailshaft and rear differential, but drive to the front wheels is more complex by utilizing a transfer case on the rear of the transmission.
The drive for the front wheels comes from a transfer case bolted on the end of an almost traditional Nissan RWD transmission. A short driveshaft for the front wheels exits the transfer case on the right side. Inside the transfer case a multi-row chain drives a multi-plate wet clutch pack. Drive from the chain is apportioned using this clutch pack in the transfer case "differential" (the system thus does not involve a regular gear differential as in a full-time 4WD layout, but rather a center clutch), similar to the type employed in the Steyr-Daimler-Puch system in the Porsche 959. This unit is lubricated with its own dedicated NS-ATF fluid supply (Nissan Special Automatic Transmission Fluid) and is not in any way connected to the fluid in the transmission. Some Nissan models have an external cooler with an electric pump to cool this fluid."

[Ilya]

Reset your ECU's. I just did it on my 2011 and the car is a totally different thing.

[StanleyNii]

Kindly share procedure on resetting the ecu's

[BlackCat81]

Contrary to what was previously posted, the clutch for the AWD system is not located in the rear differential. Nothing in the rear diff controls any of the AWD functions.

BlackCat, I thought it sounded strange myself, but a tech at my local Infiniti dealer and an Indy shop both told me the same thing when I had both F&R diff fluids replaced. They may have been confusing it with the transfer case?

"The ATTESA E-TS version uses a mostly conventional RWD transmission. Drive to the rear wheels is constant via a tailshaft and rear differential, but drive to the front wheels is more complex by utilizing a transfer case on the rear of the transmission.
The drive for the front wheels comes from a transfer case bolted on the end of an almost traditional Nissan RWD transmission. A short driveshaft for the front wheels exits the transfer case on the right side. Inside the transfer case a multi-row chain drives a multi-plate wet clutch pack. Drive from the chain is apportioned using this clutch pack in the transfer case "differential" (the system thus does not involve a regular gear differential as in a full-time 4WD layout, but rather a center clutch), similar to the type employed in the Steyr-Daimler-Puch system in the Porsche 959. This unit is lubricated with its own dedicated NS-ATF fluid supply (Nissan Special Automatic Transmission Fluid) and is not in any way connected to the fluid in the transmission. Some Nissan models have an external cooler with an electric pump to cool this fluid."

I am also a journeyman Infiniti tech. The AWD system is a totally traditional system with nothing special about it. Yes, the transfer case is what transfers power to the front wheels via the front differential. The rear end is just a run of the mill independent rear setup. I have valvoline 80w90 in my front and rear diffs, valvoline synthetic ATF in my t-case and trans. It's what we use when doing all our services. I've never had one of our t-cases apart as they're basically indestructible. My 06 M35X is about to turn 205,000 miles.

[Ilya]

Kindly share procedure on resetting the ecu's

I'm not sure what it is on the Y50...you can try the Y51 method:

howto-reset-ecu-learned-behavior-m37-m5 ... 03469.html

If you have issues, don't post in that thread please as that is a whole nother sub-forum. Thanks.

[mikew83]

I am also a journeyman Infiniti tech. The AWD system is a totally traditional system with nothing special about it. Yes, the transfer case is what transfers power to the front wheels via the front differential. The rear end is just a run of the mill independent rear setup. I have valvoline 80w90 in my front and rear diffs, valvoline synthetic ATF in my t-case and trans. It's what we use when doing all our services. I've never had one of our t-cases apart as they're basically indestructible. My 06 M35X is about to turn 205,000 miles.

That's awesome! Our Q45 just ticked past 203k last week. Infiniti's are some of the pickiest cars I've ever owned, but if you truly take care of them, they'll easily see 250-300k no problem!


IlyaKol, can't you also just disconnect the battery for 8-24hrs (overnight does the trick I believe) and accomplish the same results? I know it was the "preferred" method for my Audi A8, so I imagine it would be somewhat similar for the M, no? Unless the car is writing the ECU values to flash memory, it might do the trick. IDK

[Ilya]

I think I have heard people doing that to clear the codes in an ECU, so my guess is that it would also clear the learned behaviors. So, yes.

[StanleyNii]

Thanks @IlyaKol. I tried resetting the ECU as directed. When i get to step 5 where you depress the accelerator pedal fully till the check engine lights starts to blink, the check engine light blinks slowly 5 times and then it stop blinking. I have tried several times but it is still the same. Also when the car is engine is running idle and you rev the engine quickly (depress accelerator fully and release immediately) the rpm slowly rises to 1500 then then before idling. Revving is quite slow. Is this normal.

[Ilya]

Doesn't sound right. You're doing this with the car not running, correct?

[StanleyNii]

Yes! I do this when the car is not running. Do you think the accelerator pedal sensor could be the culprit. The VIN check results showed that "Accelerator position sensor recall is incomplete". It could be that the car was shipped out of the United States before the recall. I want to know if faulty ECU can cause acceleration and throttle response problems. Also when you turn on the ignition (without starting the engine) for 20 seconds, the service engine light blinks slowly 5 times. I am suspecting I could be having electrical problems.

[Ilya]

Yeah I don't think mine blinks but if I remember I'll look tomorrow. Then again, you have a 2007 and I have a 2011. I don't recall that though. As far as I know it turns on, stays solid, then turns off when the car is started. If yours always blinks, it's trying to tell you a PTC code or something.

[BlackCat81]

Yes! I do this when the car is not running. Do you think the accelerator pedal sensor could be the culprit. The VIN check results showed that "Accelerator position sensor recall is incomplete". It could be that the car was shipped out of the United States before the recall. I want to know if faulty ECU can cause acceleration and throttle response problems. Also when you turn on the ignition (without starting the engine) for 20 seconds, the service engine light blinks slowly 5 times. I am suspecting I could be having electrical problems.

The only issue I have with resetting all the values by doing an ECM reset is you can possibly lose idle air volume values and accelerator pedal position inputs. There's a specific relearn that needs to be done anytime an ECM Update or replacement is done, same with replacing the accelerator pedal during the recall process. I'd imagine the car would have a general idea of where those values are without the relearn, but I'm not 100% sure since I've never let one leave the shop without completing it.