Hi all,

I'm sure most of you guys have read my previous post about loose plenum spacer bolts leading to lack of power and rough idle. The issue was fixed when I tightened all the bolts. Now I have a new issue.

My car started to experience slow acceleration recently. The car is still fast, but not as fast and when I gun it, the acceleration is slow. I'm going to present my case and I would like to hear everyone's thoughts on this. I tried doin an extensive search and most lead to throttle body issues, but I do not think this is the case.

Mods:
1. Plenum spacer
2. Grounding Gear
3. Z tube
4. Aftermarket air filter
5. HKS exhaust

Baseline readings/observations while in park:
1. Idle is constant at 600 rpm (this is usual for my car)
2. Car starts up fine
3. Exhaust sounds muted
4. Intake sounds somewhat lower sounding than normal (like it isn't sucking in the same amount of air)

Symptoms:
1. Slow acceleration (climbs slowly and does not throw me back into my seat like it used to on WOT)
2. Car exahust note does not sound the same (sounds mute - I have the HKS exhaust)

What I have done to try to correct symptoms:
1. Checked plenum bolts (all torqued appropriately) - Symptoms remain
2. Changed air filters (OEM, Amsoil, and K&N) - Symptoms remain
3. Cleaned MAF sensor with CRC MAF cleaner - Symptoms remain
4. ECU reset (multiple times different days) - Symptoms remain
5. Checked if some punk kid put something in my exhaust (negative) - symptoms remain

Confounding factors:
1. Brake, VDC, and Slip lights are on - could be due to the fact I need to get a brake change - scheduled to get it done this Friday

So, what do you guys think?

 

those lights will not come on when your brakes need replacing. they are illuminating due a failure which causes those three to kick on. if you have oem or similar pads, you will hear a low pad whirring noise when you are not on the brakes. there are no sensors on this car telling you when it is time to replaced either rotors or pads. when similar lights came on in my maxima, the alternator was starting to die. how long have those lights been on? have you noticed any dimming lights?

 

Maybe if the pads are that low, the brake fluid gets low and trips those lights. I'd fix the pad problem and see if that corrects teh lights. Then see if the accerleration is still low.

 

I have seen the brake light come on for low fluid but I personally have not seen it trip any other lights.

 

From doing a search previously, people that reported those lights coming on had stated that their brakes needed to be replaced. The lights com on when your brake fluid is low. I think my brake fluid is just above minimum at the moment. Lights have been on for about a week. I am getting my car looked at this Friday to have the brakes changed.

 

Did the power drop off when the lights came on?

And yes, worn pads can trip all those lights. It happened to my friend's 04 sedan with seriously worn pads.

 

good to know, i was not aware of that.

 

To be honest, I cannot say for sure if the performance drop occurred at the same time the lights came on...

I will definitely update the thread this Friday to let people know how it was resolved. I was hoping someone on the board would give me a heads up so I know what to expect going into the dealership.

 

I can definitely tell that you are an Rx. You SOAPed the problem!

 

I had the same problem about a week ago, took it to the dealership they called a tech out to look at it without even taking it into the bay, and he said it was due to low break pads. when the pads get low the fluid level in the resivor drops setting off the lights. I picked up the break pads while I was at the dealership and changed them over the wekend; lights are off and no problems now.

 

If you have slow acceleration, the first couple of things to look at would be:
1) Air intake filter
2) Fuel filter
3) Spark Plugs (can also tell you if your gas is bad, or you are running rich/lean)
4) Something stuck in the exhaust (broken cat brick?)

after that it can be a variety of things...including low voltage, bad coil pack, weak fuel pump, plugged/obstructed gas tank, throttle body, ECU or perhaps a bad cylinder or two.

 

Interesting that you picked up on that. SOAP format is where it is at

 

Damn, that sucks that you're still having this issue. Good luck with getting it fixed!

 

Update: I just wanted to update this thread with the resolution so that anyone else that experiences a similiar problem has an idea what is going on.

VDC + SLIP + Brake = low brake pad left (my rear pads were almost non-existant)

Slow acceleration + 200 miles/tank = The Infiniti tech stated that my Air/fuel ratio was WAYYY out of spec (no idea why) and was dumping a ton of gas into the engine. He replaced the throttle body, air filter (changed from Amsoil to stock), and I think he also replaced the MAF sensor. Car is now running the way that it used to

 

how did they state they tested the a/f? to my knowledge, the consult 2 only has short & long term fuels trims and does not have the ability to monitor a/f. glad its back to normal though.