transmission laggy, n wont kick down when slowing down

[S13_newbie]

Hi. I have a 98 Infiniti i30, w/ lsd. The car has 120,000km on it, and i bought the car used, and until recently I found out the car tends to like to stays in 3rd gear even though I slow the car down to about 10mph, as long as it is not a complete stop or a big step in the gas pedal, it will not go kick down to lower gears. I thought I saw some post about the MAF sensor is not detecting enough air for the TCU to kick down. Can someone gimme some ideas on where should I start to pin point the problem?

I have flush the transmission fluid w/ Mobil1 syth ATF, and replaced oem transmission filter, and oem pan gasket when It was done. The fluid replace about 10,000 KM ago.

Thanks in advance.

[MaximA32]

Did you notice the problems before you flushed the system and all that?

[loystock]

Start with the cheapest one by cleaning the MAF sensor with zero-residue contact cleaner or CRC MAF Sensor cleaner. Also clean the ground points - battery and on main engine harness. Did you do a flush with a fluid exchange machine or just a pan drop and drain and refill? Mobil 1 ATF is very good and normally does not need additive. But if you just did a drain and refill, a bottle of Lubegard Red (ATF Protectant) may help.

[S13_newbie]

I notice that after I bought the car. At the beginning I thought it was just a Nissan transmission, but then it starting to not make sense when it stays at 3rd even when I slow the car down to 10kph or so.


I have the transmission flushed by the machine. I will go buy some MAF cleaner and try it out. I also notice the engine almost stalls when I release the gas. I found an article teaching me to clean the IACV, and I did, but it doesn't seems to help. let's hope the MAF cleaner will help.

[S13_newbie]

I tried cleaning my MAF, ian it doesn't seems to help. Are there ways to test the Maf or iacv?