amr_electron

iTrader: (8)

When you say that both the Audi & Mazda cars had the same issue do you mean that they could also accelerated well from a dead stop ?

How i wish , Actually i'm not in the US.

amr_electron

iTrader: (8)

I feel all the power is there when i accelerate from a dead stop ( even without switching the car off). But once i try to re-accelerate while driving, My God, A 61 hp Smart car will beat the hell out of my car .

X1000000.

SniperHunter

iTrader: (9)

The Mazda accelerated fine from a stop, but refused to accelerate like yours for about 3 seconds and then it'd move. It'd down shift and everything, but just hold the rev for a few seconds...and then it went.

My girlfriend's A4 on the other hand was doing PRECISELY what your car is doing. Drove fine. Had power. Idled fine. Redlined off the line. But if you shifted its gears a few times up and down, up and down, and then tried to peg it...it acted exactly as your car does, absolutely identical. I witnessed it myself numerous times.

The cam shaft turned out to be culprit, and as a result was screwing with the car's timing. The cam follower ended up damaging the cam shaft a bit, and that caused problems with the tension of the timing chain. So it was a domino effect of those three things.

The cam work performed to the car completely fixed the acceleration issues. But eventually the tension started causing noise months later, and fixing that got rid of the noise, which your car is not exhibiting. I do believe accessing the cams is a relatively easy process on our cars. And I firmly believe you should start there.

I will show this video to Performance Motorsport when I go there next weekend to get the alignment done with my new springs.

SniperHunter

iTrader: (9)

I don't think you quite understand how cams operate exactly. Revving a car in neutral with no load on the drivetrain has virtually no affect on the operation of the cams. Likewise, puttering around and accelerating like a turtle using the cruise control puts very little strain on them, as well. The amount of air they're taking in is very little.

On the other hand, flooring it or desiring speedy acceleration is triggering a timing malfunction because now you're making use of the car's variable timing, which again, directly relates to the operation of the cam. Basically, the volume of air taken in is tremendous no matter the operating speed of the vehicle and is instantly accessible for combustion. The variable aspect comes into play on how the car creates the combustion process, and at what rate. That rate is variable and dependent on throttle for much more instantaneous response and more mid-range power. Where as in the past the valves operated one after the other, (valve opens > air goes in > combusts > exhaust valve opens > exhausts) with modern day motors that have variable cam/valve timing, the valves can actually operate in multiple stages: simultaneously, sequentially, or staggered with a variable rate of operation. With variable timing, there is always air in the intake manifold just waiting for valve actuation to let it in for combustion. Without variable timing, the amount of air in the manifold is significantly less, which requires additional throttle input (wasting gas) and laggy response overall because the valves are operating inefficiently.

So basically, if the intake valves aren't operating like they should under full throttle, the car won't go anywhere. And there are a variety of factors that can cause such an issue. One being something simple like the follower. The worst being the intake cam shaft assembly.

Like I said, my girlfriend's car had the very same issue. It was perfectly drivable, but randomly wouldn't go anywhere when floored.

winchman

From OP's post #1 on page 1:

"The funny thing is, Car runs great using the cruise control switches on the steering wheel, I can rev to redline using the ACCEL/RES switch if i want."

That doesn't sound like he's puttering around.

SniperHunter

iTrader: (9)

Err...he can slowly reach redline using cruise control. Big deal? That is precisely what puttering is, hell I even added to that by saying accelerating like a turtle has little effect to trigger this. Do you know how long and slow of a process it is to use cruise control to redline? Accelerating that slow isn't going to trigger the problem. You don't seem to understand what I'm saying.

That Accel/Res switch isn't replicating wide open throttle. It is merely a way to slowly increase speed. Once again, something I defined as accelerating like a turtle.

winchman

So, we have a question for the OP. How fast does the engine accelerate when you use the CC buttons? WOT? Slowly? Something in between?

I rarely use CC, and I've never used the CC buttons to make anything other than minor speed adjustments with quick taps on the buttons. I have no idea what happens when you just hold the ACCEL/RES button down.

djamps

iTrader: (1)

CC accel/decel doesn't go anywhere near WOT...it pushes the throttle 30% at best...

winchman

Wouldn't the transmission shift into a higher gear long before the engine gets to redline if the engine was at a low throttle opening?

I'm anxious to hear from the OP about this?

amr_electron

iTrader: (8)

The engine accelerates as it should using the cruise control, I mean, You will feel the power as the RPM is climbing with every button push. If you look at the video, For some reason the RPM is not able to go more than the 3K point, But it easily goes beyond it when using the cruise control, No restriction at all 3K, 4K & it's still climbing ....

The car will continue accelerating, I mean it's not downshifting & building momentum to go wot, It's not like mashing the gas pedal of course .

From the FSM,

I'm pretty sure that it will shift to a higher gear when accelerating with the Cruise switch ( if this is what you mean ).

SniperHunter

iTrader: (9)

Once again...cam assembly, inspect it. I wrote all that and you're fixated on the cruise control. Using cruise control will almost never trigger a timing issue. I'm trying to help you understand that.

djamps

iTrader: (1)

Maybe you need to do a throttle relearn? Tried it yet?

350ztttt

iTrader: (5)

Listen to Arnold, at least have nissan check it out for free because of the whole ecu thing they put you through.

op, did you get your money back from that yet?

amr_electron

iTrader: (8)

Looks like my last resort before parting her out .

It was done more than once ( Pedal method ), And by the dealer also.

No refund man .

SniperHunter

iTrader: (9)

Have them inspect the camshaft. The follower. The valves. And the variable valve system as a whole.

Fixxxercask

iTrader: (21)

Just read through this whole thing. I am really interested to see what is causing this. Sub'd!

I was going to put in my 2 cents, but you guys covered a lot of possibilities.

I am leaning towards what Arnold is saying. I understand the difference between running it to redline with the CC controls and the the throttle. Big difference in throttle position and air coming into the engine.

One thing though; how can you get it to redline with CC? I know in my DD car (it's a manual transmission), I can put it in neutral on the interstate and set CC and it will go to redline very slowly and then just bounce off rev limiter. How is this done on a car with a auto tranny?

winchman

The clutch switch is supposed to cancel the CC when you depress the clutch, so how do you get it into neutral?

I don't understand how the OP is getting the engine to go to redline, either. I've driven cars that would downshift in CC going up a steep hill, but they would upshift long before the engine got to redline when the road flattened out a little.

Zazz93

iTrader: (2)

With a sloppy trans that pops out of gear or he is simply pushing the car out of gear (no clutch & and killing the syncros).

But I can't see this problem occuring with a camshaft or timing issue, unless the OP is describing it incorrectly. What my money is on, is some type sensor issue. But the symptoms seem a little odd.

Fixxxercask

iTrader: (21)

You're correct. It does cancel it. I was just goofing off one day and tried to set the CC once I was in neutral coasting between 60-65 on the interstate and it worked....lol The tach just slowly went all the way to redline.

winchman

OK, time for an update from OP. Did you ever get this resolved?