stopping idle issue

[jeremy242]

I have a ka24et but this issue was simmilar with my n/a sohc as well just not as bad.

I have an issue, when i come to a stop by putting my foot on the brake the revs will drop to inbetween 500 and 600 rpm. At the same time the volts will drop, and at night the lights will dim and it happens everytime when the brakes are applied. During the day when the lights are off the idle is hit or miss whether it will drop or not while braking. However every time that the rpm dips the volts drop as well. When i get to a stop all i have to do is tap the throttle and the rpms go back up to where they are supposed to be and are steady.

I have read the iacv thread about idle and i have read the grounding the tailights treads as well. None of them have any voltage drop on them. Anyone have any thoughts on this. Thanks

[QR25DE]

Bad battery or alternator....

[jeremy242]

I thought that i had it fixed to day with adding a ground from the taillight ground to the negative side of the battery (battery relocated), i was good until right before i get to work and it started acting up again. I went home and sanded all of the grounds off and cleaned the contact surfaces with some sandpaper and it didn't help. I start out with 12.5 on the volt meter and then by the time i get dow the road it is 12 and then when i put my foot on the break it drops to 10.5 and the rpm drop starts. I tightend up my alternator belt to see if that was it but no good. I am going to go and get the alt and the battery check later today. The alternator only has 13k miles on it and the battery is less than two years old.

[srpowered240sx]

I thought that i had it fixed to day with adding a ground from the taillight ground to the negative side of the battery (battery relocated), i was good until right before i get to work and it started acting up again. I went home and sanded all of the grounds off and cleaned the contact surfaces with some sandpaper and it didn't help. I start out with 12.5 on the volt meter and then by the time i get dow the road it is 12 and then when i put my foot on the break it drops to 10.5 and the rpm drop starts. I tightend up my alternator belt to see if that was it but no good. I am going to go and get the alt and the battery check later today. The alternator only has 13k miles on it and the battery is less than two years old.

sounds like the alt, you should be pushing 13-14.5v when driving.

[jeremy242]

alternator tested out good as well as the battery. I pulled the iacv this morning and the spring visible from the inside of the valve was not there, i didn't check it prior to install so i just put the one i had on my n/a motor on it and i am waiting for the rtv to set and cross my fingers.
The volts have always been around 12.5 when running so i don't know. I will look into it more if this dosnt help.

[jeremy242]

After doing some research i belive the problem may be due to the fact that i am running an underdrive pulley on the factory alternator. My issues are only during the times when the fans are on so i think it is a voltage issue due to the alternator only spinning at 65 amps. So i have two choises buy the quest alternator or swap back in my stock stuff. i think i will do this tonight and see if that clears it up. If it does then i will look into the quest cause i got to have the blinging billet pulley

[OutToWinPAHC]

Check for vacuum leaks.... brake booster

[jeremy242]

ow do you check the booster, i have all new lines run to it and they are clamped. It would make sense that it was in the braking system but i only have the problems when the fans are on otherwise the car runs fine.