Air intake temp sensor & Boost Sensor
 

Hi to all!
My FC has always made around 10-11 mpg. I did almost anything I could think off (spark plugs, spark plug wires, O2 sensor, widebanded and setted A'pexi SAFC, checked for error codes...), but still no good. The interesting part is that nothing changed the milleage significantly.

Recently I noticed that the air intake temp sensor, the one in the throttle body just after the IC, with 2 little contacts, is disconected (contacts are broken). Could this be the cause for the low milleage? If so, would replacing it require me to re-wideband?

Also, due to cold weather, the boost raised from 7-8 to around 10psi, but I experienced no fuel cut. I have a standard N318 (JSpec) ECU. Could it be a bad Boost sensor? In which pin at the ECU could I check the voltage? Which range should it have?

Thx for any help.
Best regards

Alejandro

On a series four, it's pin 2B that shows the boost/pressure sensor output. The voltage will be low at idle and increase with boost. Somewhere around 3.65 (memory here) is where fuel cut happens on a USA version.

So watch the voltage as you boost and see how high it goes. Maybe JSPEC don't have fuel cut???????????Got me, I don't own one of those.

Another way to see if the boost sensor is outputting is to watch your STOCK boost gauge. No movement means you've electrical problems with the boost sensor.

Thx HAILERS,
I don't have a stock boost gauge as mine is a T2 swap. I'll check the voltage this sunday and see what happens

About the air intake temp sensor, do you have any idea about how could re-conecting it affect my AFRs?

Best regards
Alejandro

YES.

I don't understand this question.



-Ted

I think he means re-tune his wideband o2 sensor. I would think so yes. Heh.. correct me if im wrong of course ;)

I mean, if I reconect the intake air temp sensor, will that change my AFRs? I tuned for mid 11s with the sensor disconected. Shoud I tune again with the wideband once I reconect the sensor?

i've been told that jspec's dont have the fuel cut. us has em cuz of emissions(i think) does the s4 n/a have an air intake temp sensor?..if it doe..where?

The series four non turbo and turbo both have two air temp sensors.. On a non turbo one is built into the afm and the other is located on the left side of the dynamic chamber.

thanks hailers. i 'ppreciate it.

So, will reconecting the intake air temp sensor affect my AFRs requiring my to tune again my SAFC?

check for the air temp sensor on the throttle body its right under the intercooler it tends to flop off the 2 connectors