Gas Pedal Delay

G Fo12ce

I read over most of this the other day. Today I was going through the Oct. Option magazine and came accross an alternative to the Sprint Booster from Blitz called the Blitz Throttle Controller. I made a post about it HERE if you care to discuss.

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RCZ

are you guys just stomping on the throttle with low revs? this isnt a corvette.. Mine only ever does it when I stomp full throttle at low rpm. That's normal though..

cfleming2226

I get what you are saying and yes my issus comes when I floor it at low RPM's. i'm not expecting it to take off as a Corvette would, I just found it odd that there was such a delay in anything happening. Heck, my FX 35 would respond faster in the same situation.

Jordo!

No perceptable delay on mine.

'09 or '10? Might be slightly different ECU logic?

Any mods? Intake or exhaust might throw off tip-in fueling.

EDIT: looks like a lot of folks with this issue have intakes. Yep, either by throwing off MAF signals or actually drawing in more air and running leaner, tip-in will be affected most noticeably.

On tip-in, the ECU will add extra fuel for smooth transitions from one location in the map to another. You should be able to get that tuned -- but it will have to be ROAD tuning.

I don't think you can adjust tip in effectively on a dyno.

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spearfish25

My girl takes off when I floor it. I can 100% agree with the oil temps affecting response though. It's incredibly dramatic. Below ~220F, the car accelerates like a banshee, but above ~220F it gets progressively more lethargic. Thank God my oil cooler is on the way!

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cossie1600

The drive by wire/ECU mapping creates a slight lag at the lower RPM, the only thing you can do is flash the ECU. If you have driven a 350z, you will know the 370's throttle response is not up to par.

cossie1600

How low were you going, 1500RPM?

Jordo!

If not due to poor tip-in tuning or oil-temps, then I have to wonder if there's a a '09-'10 difference in the ECU logic.

Other possiblities would be slight variances between vehicles in the TPS sensor interpolations which cause intermittent delays.

Possibly, dirty MAF sensors/clogged airfilters throwing things off a wee bit -- more common in cars with some miles on them, driving in dusty locales?

After that I'm wondering more or less common for AT or MT?

This isn't voodoo -- it should be something one can narrow down and address with a re-tune or a bit of cleaning...

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RCZ

^ I think I know what you guys are talking about and this isn't the only car where this happens. It always feels better to roll on the gas than to just stop it to the floor, right? I know the problem and I get a feeling it has more to do with the way the ecu does the fueling and plain mechanical inertia from the low RPM's...

Those of you that described the problem...what RPM are you stomping at? under 2500rpm? If it is, then its normal and possibly built in safety to protect your drivetrain...

m4a1mustang

For me its anywhere under 3-3.5k. It just doesn't make any sense (to me anyways) to build in 2-3 seconds of zero acceleration as a safety. It doesn't really matter if I go WOT either. If I'm accelerating from a light and at 2500-3000 I decide I want 50 percent throttle the same thing happens. The car just dies and does nothing, then 2-3 seconds later it takes off. Doesn't seem like a safety to me. Need to check some things out this weekend... probably need to log my a/f ratios to see if they are out of whack in the lower ranges.

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KillerBee370

Yeah it doesn't seem like a safety thing to me either. The best way I can describe it (if indeed I am experiencing the same thing you guys are) is that when you are driving at a certain way for awhile, let's say normal cruising, the ECU picks up on this and adjusts itself to give the car the best possible mpg etc. for that type of driving. Then if I were in say second or third (or even from a dead stop) and decide to stomp the peepee out of it, it goes like a bat outta hell without issue. THEN upon bringing it to a stop or returning back to a lower gear and normal driving, it will stutter a bit when the gas is applied (either from a dead stop or rolling in any gear).

What leads me to believe that it is an ECU thing is that it is consistent. In other words, it doesn't seem like a random problem such as dirty sensors or bad gas or something of that nature. This would also explain while at the track when the consistency of the driving is constant mashing of throttle etc, it wouldn't do this because the computer is setting itself for this particular type of driving.

Does this sound similar to what you guys are experiencing? It's probably a normal function of the computer but i find it a bit frustrating during spirited driving to yield to electronics rather than just have the car do what you want it to regardless like an older car would without drive by wire.

KillerBee370

I will take it out and see if I can video the problem and post it here.

cossie1600

the 08 09 sti had the same problem. as i said, it is a byproduct of the drive by wire/emissiontuning. it has nothing to do with oil temp. if you think your car is fine, try driving a 350 to compare. the tuner should be able to adjust that easily.

this is very noticeable for guys who autox, i think the throttle gets more aggressive as the rpms go up.

Jordo!

Hmm. Well, those of you have this issue (especially those who have aftermarket intakes and no tune), definitely see about spending a little time on the road playing with tip-in fueling.

Best way to do this is big open parking lot (stop and go with various degrees of throttle input) and then empty road to play with this at crusing speeds.

PITA to tune, and pretty much all done by feel (i.e., there is no target AFR per se, it's just what feels good -- typically this involves skewing a tad rich momentarily, although ideally it would go directly to whatever AFR you would have in next map cell).

You should also be able to tweak tip-in ignition too, which will make a huge difference in responsiveness. Torque output restrictions on tip-in generally involve pull timing.

Put it back (with a slight risk of burst knock, so be careful!)and you will get way better responsiveness!

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david712370

I noticed this problem as well in my manual. I tried turning off the VDC with no change. However when i turned the rev match off it appeared to make a difference. I am wondering if I am just imagining the difference, since it doesn't make any sense to me while it would help with the throttle response. Has anyone tried this?

Also, I have no mods and I can report similar issues with a delay in acceleration below 3k. Just my $0.02.