Power loss diag update - snow button

[HailDamage]

Power loss diag update - snow button

So I have come across something that seems to have fixed the very slow responsiveness of the throttle in my series 1 RS4 auto today. I met up with the local stagea owners over the weekend and I heard at some point that the snow button on the centre console pressurizes the Atessa system when it is flicked on. So I thought that maybe in my car it is not pressurizing correctly upon ignition and that might be why the car feels so sluggish. I tried it this morning I flicked the switch to "snow" and back to "power" a couple of times and there it was: torque, accelleration, response.

I can now feel the difference between off boost and on boost more defined and the wheels spin much easier too. So is there any info you guys might have or know of about how the "pressurizing" of the Atessa system works? Should I get the awd serviced maybe?

[KiwiRS4T]

The snow button makes the transmission take off in 2nd gear and acts like the dash button for the atessa putting it in 50/50 mode til you achieve about 20km/hr.

[HailDamage]

1 hour ago, KiwiRS4T said:

The snow button makes the transmission take off in 2nd gear and acts like the dash button for the atessa putting it in 50/50 mode til you achieve about 20km/hr.

Yes I'm aware of this. When I bought the car I was made aware it had a issue with the trans starting in 2nd gear. The previous owner's fix was to stop and start the car again any time this happened. I've noticed that the issue with starting in 2nd has not been present at all for over a good month. Maybe that old problem is linked to why I am seeing an increase in throttle response when switching to snow mode and back. Could it be the switch itself?

[zoomzoom]

Id be wary about fooling yourself. You really need to collect some data through a consult cable to see what the ECU is doing, and what the sensors are reading. Being quite a simple old engine, it doesn't have much of ability to vary things like throttle response, except maybe through timing adjustments. But Ive never seen the stock ECU do that other than when the coolant is cold, retarding timing for full throttle auto gear changes, and safety features like knock protection.

The snow/power rocker switch seems to only affect the gearbox mapping.

Start with the most logical thing. Throttle response starts with the engine. You need a good air supply, so check all piping, including intercooler, and throttle body to make sure they're not gunked up. Then check fuel delivery and ignition. You can check the base timing manually while stationary, but once youre on the move you need a consult cable to read what the ECU is doing.

Some things that spring to mind: retarded timing can sometimes fool you into thinking there is more power as the turbo will spool up sooner/faster. While this might seem more exciting its still making less than optimal power. It will feel extremely gutless off boost.

Again, you need to collect data to see what the timing is while on the move.

[HailDamage]

Definitely, that's why I made the thread to gather more information in a new direction of my diagnosis. I have done a few things since I got the car so this isn't my very first idea. I've had boost leaks which I'm faily certain are fixed or very minimal (yeah i know minimal is as good as bad boost leak). I had a faulty boost controller now replaced. I had spark plugs replaced and rocker cover gaskets replaced. I've had mechanics drive my car to confirm the auto box isn't slipping. But no you are right I haven't had either the ecu or timing looked at. At the same time I'm definitely getting a huge effect by flicking this switch.

As for boost coming on early, I found after flicking the switch it felt like it came on a bit later but stronger and that's with a whining most likely on it's way out turbo. Before flicking the switch my gauge would read 10 or so but honestly felt the same as stock or maybe less. I don't know how I could possibly explain the switch affecting all of this so drastically, because I don't dispute that all it does is affect the gearbox mapping, but I feel more is going on than just that.

[jimwall80]

My car, too, is suffering from lack of acceleration. The engine light is on and I fear having a terrible accident during an engine delay/ late response when driving away from a light or curb. I intend to look at my ignition timing but need BTDC info and the revs. Can anyone help with the infor? Would be greatly appreciated. The engine is a VQ 25 (DD). The car is 2004 Nissan stagea, 250 RX four. Thanks in advance

[m35stagea]

On 5/3/2017 at 10:49 PM, jimwall80 said:

My car, too, is suffering from lack of acceleration. The engine light is on and I fear having a terrible accident during an engine delay/ late response when driving away from a light or curb. I intend to look at my ignition timing but need BTDC info and the revs. Can anyone help with the infor? Would be greatly appreciated. The engine is a VQ 25 (DD). The car is 2004 Nissan stagea, 250 RX four. Thanks in advance

 

If you are in sydney i can have a look at the codes for you. 

[HailDamage]

Alright I think I was on the wrong track with the diff/AWD system. I'm now certain the power loss is coming from a possible air leak in the trans. Yesterday on my first drive it was really sluggish and it turned out that the dipstick for the trans had popped up so I put a bit of tape on that to give it a better seal (is it supposed to have a rubber 0-ring perhaps?). Last night I went on a cruise and I noticed the pressurization of the gearbox was very inconsistent and at one point I even lost all power coming through the box for a few seconds but I don't think the dipstick came out again. Could be the seals, or I'm also thinking could it be symptomatic of a bad torque converter?

[SLIXK]

On 5/7/2017 at 12:57 PM, HailDamage said:

Alright I think I was on the wrong track with the diff/AWD system. I'm now certain the power loss is coming from a possible air leak in the trans. Yesterday on my first drive it was really sluggish and it turned out that the dipstick for the trans had popped up so I put a bit of tape on that to give it a better seal (is it supposed to have a rubber 0-ring perhaps?). Last night I went on a cruise and I noticed the pressurization of the gearbox was very inconsistent and at one point I even lost all power coming through the box for a few seconds but I don't think the dipstick came out again. Could be the seals, or I'm also thinking could it be symptomatic of a bad torque converter?

Did you end up solving ur issue?