Throttle / Shift Lag after TCM flash?

[Triple_X]

Originally Posted by G35Rhino

However the throttle lag and/or shift lag concerns me greatly and is new for me since the reprog. I have noticed it 3 times. The first I was being cute and floored it from a 3 - 5 mph rolling start and the car did not respond at all (it felt like it was in 3rd gear or something) rather it just slowly climbed up to speed for a couple of seconds before dropping down into the right gear and taking off like a bat out of hell. It was a bit embarassing as it sounded like the car was flooding out before it kicked into lower gear. The other 2 times were when I was crusing the interstate and gave the car considerable gas to pull out and pass...again the car didn't downshift rather it felt like it "missed" even though the engine was purring smoothly and then finally started picking up speed gradually before dropping a couple of gears and taking off. That's a good way to get yourself killed at 75 mph.

happens to me almost daily in DS Mode. It is so friggin annoying, but apparently doesn't bother me enough to take it to the dealership...

basically exactly how you described...slowly accelerates then when you least expect it, the SOB takes off... not very safe or flattering

also in D, if I mash the pedal it takes a good second or two to kick in. Hoping the grounding kit eliminates some of this.

[hadokenuh]

I think it's the problem with Drive-by-Wire technology. Does our G have DBW?

I had a Lexus RX330 with the same problem, but I didn't care because it was a Lexus. I understand the G is supposed to be a performance car. So this should not happen

[Riley]

Yes, the G is drive by wire as most cars are now.

However DBW shouldn't have this issue.

[G35Rhino]

Originally Posted by Triple_X

happens to me almost daily in DS Mode. It is so friggin annoying, but apparently doesn't bother me enough to take it to the dealership...

basically exactly how you described...slowly accelerates then when you least expect it, the SOB takes off... not very safe or flattering

also in D, if I mash the pedal it takes a good second or two to kick in. Hoping the grounding kit eliminates some of this.

Damn straight....that's my problem.

As for the grounding kit discussion, did not intend (or want) that to takeover the thread rather just trying to find out if I was the only one with this problem. That doesn't sound like the case though although apparently not as widespread as the flare issue.

[G35Rhino]

Originally Posted by hadokenuh

I think it's the problem with Drive-by-Wire technology. Does our G have DBW?

I had a Lexus RX330 with the same problem, but I didn't care because it was a Lexus. I understand the G is supposed to be a performance car. So this should not happen

Yes, DBW but everything is linked (electronically) to everything else thus who can say it's DBW, TCM and ECM or anything else without looking at it? What scares me is that unless it's throwing codes, which it is not, I'm sure the dealer will tell me "unable to replicate" and I do not have time to take it to the dealer 10 times before they can replicate it. By then I'll be so pissed about the car I'll hate it and I do not want that to happen.

Did that with one of the first 6-speed TL's to roll off the line in 2004....made Acura buy it back and then I switched to Infiniti. I love my Infiniti(s) so I guess I'll just have to put up with it until someone else gets pissed and figures it out.

[Herkypilot]

G35 Rhino,

I just had mine flashed today at Charlotte Infiniti. I've had my car since Feb and I've been pretty impressed with the service dept there. I'll let you know how the shifting goes. The drive home was fine. I was thinking about the mileage being affected so I'll keep an eye on it using manual calculation method. I never have trusted the on-board computer. Before the flash, I was getting 25-26 MPG average with 80 hwy/20 city. My best was all hwy up to VA which I was able to get 30 MPG. I'm hoping it's not affected by the flash as I was enjoying what I was getting!

[brynomon]

I haven't experienced much throttle lag bug the car was chugging on a very humid day. My mpgs did not get worse either. Waiting to see if this chugging happens on another warm humid day but the weather has been very un-summer like.

[G35Rhino]

Originally Posted by Herkypilot

G35 Rhino,

I just had mine flashed today at Charlotte Infiniti. I've had my car since Feb and I've been pretty impressed with the service dept there. I'll let you know how the shifting goes. The drive home was fine. I was thinking about the mileage being affected so I'll keep an eye on it using manual calculation method. I never have trusted the on-board computer. Before the flash, I was getting 25-26 MPG average with 80 hwy/20 city. My best was all hwy up to VA which I was able to get 30 MPG. I'm hoping it's not affected by the flash as I was enjoying what I was getting!

Thanks for the feedback and by all means let me know if you notice any differences (mileage or otherwise). I got my car on Jan. 30 so you and I have been in the cars roughly same time...although I got pissed at Infiniti of Charlotte and went to Lake Norman this time (my G prior came from Infiniti of Charlotte).

IMO Infiniti of Charlotte's customer service has gone down since 2005 when I lease my '05 G35. I believe they have changed ownership (now part of Sonic) and that may have changed their philosophy somewhat.

[G35Rhino]

OK so this happened again today and I'm starting to be able to narrow it down a bit. It seems that I am having issues when I am rolling/coasting and then floor it. It has happened in D at 5 mph or so when I gunned it (requiriing it to downshift) and I noticed it big time today when driving at ~40-ish mph then gunned it to force a downshift. I tried it several times in a row and when the car was rolling/coasting downhill (less of a load thus throttle partially closed) at ~40 mph it lagged big-time however doing same on an uphill grade (having to constantly feed fuel) the car did fine. Any ideas?

[ozzypriest]

My G8 Gt suffered from this from time-to-time, it was drive-by-wire. It was transmission protection programmed into the TCU. A tune similar to the Cobb accessport fixed this issue. What I don't understand is why is there not a trans tune for the G37? Is the TCU not accessible for re-programming? Can the tuners not figure this out? Is there something about the TCU that makes it difficult to tune or access? IMO, the 7AT has a total granny tranny in the sense that there is a LOT of torque management & lack of good shift pressure, and PURPOSEFUL throttle lag, probably there in order to avoid drivetrain lash, etc. That throttle lag is also **there on purpose**. It's the Infiniti engineering team's response to ensure drivability and drivetrain component sustainability. They, like most manufacturers, are being extra careful.

That being said, I removed most of the torque management from my GT, adjusted the shift pressure and shift points, and I was a happy m-fer. It was a performance tune, and too rough for a lot of people, but just adjusting the transmission made the car about .4-.6 secs faster 0-60, and about .3 secs faster in the 1/8 and 1/4 mile. So where's the transmission tune for the G37 AT?

[G35Rhino]

Originally Posted by ozzypriest

My G8 Gt suffered from this from time-to-time, it was drive-by-wire. It was transmission protection programmed into the TCU. A tune similar to the Cobb accessport fixed this issue. What I don't understand is why is there not a trans tune for the G37? Is the TCU not accessible for re-programming? Can the tuners not figure this out? Is there something about the TCU that makes it difficult to tune or access? IMO, the 7AT has a total granny tranny in the sense that there is a LOT of torque management & lack of good shift pressure, and PURPOSEFUL throttle lag, probably there in order to avoid drivetrain lash, etc. That throttle lag is also **there on purpose**. It's the Infiniti engineering team's response to ensure drivability and drivetrain component sustainability. They, like most manufacturers, are being extra careful.

That being said, I removed most of the torque management from my GT, adjusted the shift pressure and shift points, and I was a happy m-fer. It was a performance tune, and too rough for a lot of people, but just adjusting the transmission made the car about .4-.6 secs faster 0-60, and about .3 secs faster in the 1/8 and 1/4 mile. So where's the transmission tune for the G37 AT?

I had a similar issue with a Fiero (back in the 1980's kids) but that was pre-DBW. It was a faulty Throttle Position Sensor.

I SERIOUSLY DOUBT the issue I am having is a conscious thing on the part of Infiniti. There are too many enthusiasts here to not be complaining about this problem so I do not believe it is a characteristic of the car in general. I think a small subset of the population is having issues not widespread.

[saltfish]

As ozzypriest mentioned i think the throttle lag is there on purpose and i also believe that the reason why its there is because its a safety feature. Reason being is that in case you have an emergency situation (panic stop) and accidentally slam on the throttle instead of the brakes, you would not want to accelerate faster into the accident. That delay gives you enough time to notice that you are not stopping as you should be and allow you to readjust yourself to apply the brakes.

This is why if you have a constant feed of fuel you would not experience any throttle lag (not a panic situation) however if you were to close the throttle and then gun it (can be interpreted as a panic situation) you would experience some form of delay.

[KLB]

Originally Posted by ozzypriest

My G8 Gt suffered from this from time-to-time, it was drive-by-wire. It was transmission protection programmed into the TCU. A tune similar to the Cobb accessport fixed this issue. What I don't understand is why is there not a trans tune for the G37? Is the TCU not accessible for re-programming? Can the tuners not figure this out? Is there something about the TCU that makes it difficult to tune or access? IMO, the 7AT has a total granny tranny in the sense that there is a LOT of torque management & lack of good shift pressure, and PURPOSEFUL throttle lag, probably there in order to avoid drivetrain lash, etc. That throttle lag is also **there on purpose**. It's the Infiniti engineering team's response to ensure drivability and drivetrain component sustainability. They, like most manufacturers, are being extra careful.

That being said, I removed most of the torque management from my GT, adjusted the shift pressure and shift points, and I was a happy m-fer. It was a performance tune, and too rough for a lot of people, but just adjusting the transmission made the car about .4-.6 secs faster 0-60, and about .3 secs faster in the 1/8 and 1/4 mile. So where's the transmission tune for the G37 AT?

Read this thread

[G35Rhino]

Originally Posted by saltfish

As ozzypriest mentioned i think the throttle lag is there on purpose and i also believe that the reason why its there is because its a safety feature. Reason being is that in case you have an emergency situation (panic stop) and accidentally slam on the throttle instead of the brakes, you would not want to accelerate faster into the accident. That delay gives you enough time to notice that you are not stopping as you should be and allow you to readjust yourself to apply the brakes.

This is why if you have a constant feed of fuel you would not experience any throttle lag (not a panic situation) however if you were to close the throttle and then gun it (can be interpreted as a panic situation) you would experience some form of delay.

I don't buy it....I could be wrong but I just don't believe Infiniti would put you in a 328 hp car, let you think you have the power to pull out at speed in a high-traffic / high-speed situation and then leave you sitting there to get run over when the car hesitates.

[saltfish]

I went to the BMW performance driving school and an instructor described some throttle delay (not exact words) which BMW incorporates as a safety feature in case of a panic situation.

I i'm not saying that Infiniti incorporates the exact same logic however i can see where it would come in handy in a panic situation.

You should try gradually depressing the throttle as opposed to stomping on it and see if it behaves differently.