NC flat spot/hesitation into 6th

reflex · Postby **reflex** » Fri Feb 04, 2011 3:23 pm

I've got a consistent hesitation/flat spot in power delivery. I mainly notice it after shifting 5th-6th at freeway speeds.
Immediately as i get back on the throttle after shifting into 6th, there is a half second (very noticible) dead spot, like the TC has killed 50% of the power.
this also happens while crusing in 6th, then give the throttle a squeeze, not a big boot just a light to medium squeeze, same thing 1/2 second flat spot.
I only notice it in 6th.
Any clues, would this be a software issue that mazda could identify at next service etc?
its a 2006 build NC PRHT. 66000klms. I have had the car from 15000klms and it has done this the whole time i've had it.
thanks.

Charlie Brown · Postby **Charlie Brown** » Fri Feb 04, 2011 4:07 pm

Mazda should be able to fix it though I wouldn't hold my breath. :roll:

Mazda couldn't solve my cold weather idle oscillating problem during the three years warranty period and I still have it 5 years down the track. There excuse, “ it can be anyone of a number of sensors so we’ll wait until it breaks completely and fix it then!!!” :evil:

Yours sounds like "Fly by Wire" problem in/to the computer. (Remember there's no cable to the injection system, it’s all electronically controlled).

reflex · Postby **reflex** » Mon Feb 07, 2011 3:30 pm

Yeah i gotta say the FBW throttle is my one pet hate with this car. I dunno if its just me, but heel toeing is not as quick and smooth as it should be ,cause a quick kick to rev match just doesn't bring the revs up, i've got to hold my heel on the throttle for 1/2 count to get the revs to rise. My mum has a fiesta XR4 with FBW throttle aswell, (basically same engine as NC, just different tune) and when that was new I thought that had a slight lag to the throttle during heel toe, but compared to my NC its bliss!

I'll see what Mazda has to say, and i'll secifically ask them to check for software updates etc.
Cheers

JBT · Postby **JBT** » Mon Feb 07, 2011 3:49 pm

Our car is a 2007 build and doesn't have the problem yours does. Heel/toe during down changes is also a breeze.

reflex · Postby **reflex** » Mon Feb 07, 2011 4:06 pm

JBT wrote:Our car is a 2007 build and doesn't have the problem yours does. Heel/toe during down changes is also a breeze.

Cheers, thanks for the feedback.
this will be another item on the "Mazda please check" list.
Currently the list is as follows
Flat spot into 6th.
Lag on heel toe.
Bad ping when ambient air temp is over 35 degrees.

Is it just me or is all this sounding fuel/intake system (software?) related. hmmmm.

Mr Morlock · Postby **Mr Morlock** » Mon Feb 07, 2011 5:50 pm

I wonder why it has taken so long to address the issue- clearly this is problem - the car should not have any flat spots, pinging or hesitation etc. Old cars were often beset with inherent faults but surely not moderns. Heel and toe is not necessary for modern road cars- whether you do it or not is not related to the problem.

JBT · Postby **JBT** » Mon Feb 07, 2011 6:26 pm

reflex wrote:Is it just me or is all this sounding fuel/intake system (software?) related. hmmmm.

It certainly sounds like a software or electronic issue.

JBT · Postby **JBT** » Mon Feb 07, 2011 6:56 pm

Mr Morlock wrote:Heel and toe is not necessary for modern road cars- whether you do it or not is not related to the problem.

I dispute both those statements. It is necessary during track/competitive events for smooth progress and is useful during normal driving. It will certainly be more difficult if there is a dead spot or throttle response hesitation.

Mr Morlock · Postby **Mr Morlock** » Mon Feb 07, 2011 7:32 pm

Not for moderns - track work sure but road use it is like double de clutching- crash boxes went out in the 30's. The dead spot should not be there- ie fix the root problem

bigdog · Postby **bigdog** » Mon Feb 07, 2011 9:43 pm

Mr Morlock wrote:Not for moderns - track work sure but road use it is like double de clutching- crash boxes went out in the 30's. The dead spot should not be there- ie fix the root problem

Rev matching when changing down a gear while braking is essential if you don't want the rear tyres to lock up and undue strain put on the drivetrain. Once again your advice is neither on topic or helpful Mr Morlock.

reflex · Postby **reflex** » Tue Feb 08, 2011 2:42 pm

Mr Morlock wrote:I wonder why it has taken so long to address the issue- clearly this is problem - the car should not have any flat spots, pinging or hesitation etc. Old cars were often beset with inherent faults but surely not moderns. Heel and toe is not necessary for modern road cars- whether you do it or not is not related to the problem.

My delay in addressing the problem is mainly due to the hesitation only being when going into 6th gear, so not a real drivability issue, and the flat spot on downshift heel toe, I learnt to drive around it. And as I am planning on putting it into Mazda for its next service, I thought i'd put together a list of all niggles that my be corrected with software updates.
The ping in hot weather, again, learnt to drive around it, I put a can of the subaru upper engine cleaner through it at the 60K service which helped the ping, so maybe it was just carbn deposits in the the inlet manifold.

As for heel toe not being necessary in modern cars. I prefer to rev match etc on downshifts as its an easy technique to potentially relieve some of the unecessary load on the driveline (agree with bigdog here).

But Mr Morlock, your right in saying "fix the root problem" hopefully I will.

Cheers.

Charlie Brown · Postby **Charlie Brown** » Wed Feb 09, 2011 8:45 am

Yep, agree with everything JBT & BD have said. Mazda should do a re flash on the computer to fix all your engine related problems. No lag in throttle response on mine or pinging even in the 41 degree temp of last week when accelerating with the air conditioner on full.

Mr M,
116,000 kilometres on my 5+ year old NC to date.
Probably 30+ track days.
I ALWAYS match revs on gear changes.
The result of this is that the clutch is still going strong.