Gas Pedal Delay

DIGItonium

I forgot to get the entire print. The switch costs a little over $100. There are two switches in the brake pedal assembly, and so far only one was the culprit.

Below is my post in Mike's thread with pictures of the switches. His brake switch was out of adjustment, and he mentioned throttle was limited to 15%. When throttle is cut, there are no codes or warning lights. My switch couldn't be adjusted, so I had to shimmy it. My car was stock at the time, and the motor screamed. It sounded different. Plus, I was able to easily break loose the tires as I gradually depressed the pedal to the floor.
I have a serious engine problem

Fast forward to today, when I had power issues in 1st and 2nd the ambient temps were in the 40s. Oil temps were around 180F. I tend to get the car going under 2k RPM, so there's an annoying stall under 2k RPM before quickly ramping up afterward. It's pretty inconsistent and difficult to drive smoothly. There are times I feel a dead spot as I press down the gas pedal. I can feel the power build up to about 3-4k RPM, and then it stops abruptly. Pressing further down to the floor didn't make a difference. The linear feeling wasn't there. Boost would ramp up slowly in parallel with the tach, which was unusual. I had issues getting out of vacuum beyond 3k RPM at times, so I thought there was a leak.

So far the car is running great, and the ambient temps are in the upper 40s and 50s. I've had the oil temps as high as 200F and power feels consistent. I can feel the power build up from tip in regardless of the gear I'm on. It is easy to exceed the speed limit while gradually depressing the pedal down to 50%. So far I haven't felt any dead spots. Power continues to build up as I depress the pedal. Also, there's a nice feeling at highway speeds in 5th and 6th in which I can get the car to scoot with little effort. Basically starting out in 1st does not feel like starting out in 2nd. I've not had that feeling.

Also note I never had cruise control problems. So far it never disengaged on its own, so perhaps the other switch disengages cruise control. [shrugs]

I don't think this fix will resolve the power issues on super hot days, so an oil cooler is still recommended.

[EDIT] 370zgirl had this problem and had the switch replaced:
09 370z engine sputtering while accelerating

__________________

ZForce

Both Z's are getting the brake switch replaced under extended warranty. $50 deductible might be waived by dealership. So I will have two cars to test if this resolves the problem. BTW they are running with 25 row oil coolers and INJEN CAI's.

Monday morning is appt day. Replacing the brake switch that controls the computer (not the brake light one). No issues with cruise control.

kenny's 370z

after trouble shooting again after so long since i had given up,i tried something today that fixed my throttle issues after applying the brakes.i thought that maybe i had a bad brake switch also.

in my case,something inside my brake booster was giving the map sensor a bad reading with the vacuum.found out after putting a T on the brake vacuum hose at the i m and then running a hose to the map sensor by the brake booster and plugging the hose coming off of the brake booster that went to the map sensor.to my amazement,this worked.

i have said in the past by doing this and that it fixed my problem.what i was doing was making the car run richer until the computer compensated but the problem always came back.

since the map sensor is now bypassed from the brake booster.my problems with throttle problems have disappeared.i had all but given up on this car until today.this may or may not work for the people that cant figure their problems out with throttle problems either.its completely reversable and i have run the crap out of the car during my testing.

i also notice,my oil runs cooler and my gas mileage went up with normal driving.i know for a fact that the map sensor by the brake booster was making my car run lean as hell.it would smell like gun powder after i got on it.i dont smell that anymore either.i went from hating this car to loving it again.

so far,there are two culprits of throttle problems(excluding vdc) that i know of,brake switch and map sensor by the brake booster.one cuts throttle and one leans the car out

kenny's 370z

i wont edit this post^ in case someone else wants to try it.dont waste your time.apparently,it IS my brake switch also.the brake switch that is farthest to the right(closest to the foot well ) is the one that kills cruise when you apply the brakes.

i adjusted this one out to where i dont have cruise atm.but guess what,by doing this,the computer no longer thinks im applying brakes when im not.so there it is.BRAKE switches.and i put the map sensor back to stock.car is running great.so if you want to try and trouble shoot your brake switch,take a 14mm open end wrench and loosen the switch im describing,unscrew the switch about an 1/8th of an inch,maybe more,then tighten the nut back down and go for a drive.

what i believe has happened in my case is the nipple is wore down on the switch that controls the brake lights and the other switch isnt letting the brake light switch be compressed all the way.drove this morning to work and back home for lunch and back to work with ZERO throttle problems and i tried to get it to show its ugly face again and wouldnt come back.and the car definitely feels easier to get rolling.