Urgent Problem

[Guest nismogtsx]

My R31 GTS-X is sureing in rev's at idle

500rpm > 1000rpm.

My apexi TT is showing a constant air/fuel ratio of 20:1

This serging only happens once the car is warmed up...

I believe it could be an O2 sensor.....

Because it runs fine when cold and then once boosted it

runs really bad..... Once warmed up the car does not deliever

power properly and has trouble changing into 3rd gear until

you back off. The problem is worsened once the alternator is loaded or the power steering pump is worked.....

I thought of the exhaust gaskets too but because boost

is still being delived smooth and constant i think it will

be the O2 sensor.....

Whats your thoughts.....

How much would you pay for a new one or second hand one???

This is an urgent problem as i have a test & tune this week

and the car has dropped all of its power....

I think i got like 100rwkw atm.....

Its smooth to drive but just has no power.....

NOTE: I will post this in a few other places around this forum to

ensure everyone see's it and i can get a formed opnion...

Thanks Colin

[Clint32]

the apexi TT air fuel ratio maxes out at 20:1 so i wouldnt realy on this.

[Guest nismogtsx]

Yeah but it ran fine until yesterday......

I used to run inbetween 15:1 and 12:1 depending on boost

But now its stuck on 20:1 all the time......

This only occured when the problem occured

[Cubes]

I was under the impression that the O2 sensor only worked under light throttle cruising.

Accelerating fuel etc is determined by the Maps stored in the ecu.

But it could be doing funny things?!?

[Guest nismogtsx]

Ok, i have seen my turbo guy...LOL

Its the Water temp sender.... Funny that...

The NICS Rb20det reley's on the temp to tell the computer

about the amount of fuel it needs as well as air temp, O2 sensor

and about 6 other sensors.... LOL

But the O2 sensor is stuffed as well, cause by over fueling

the O2 sensor once drowned in fuel is inactive...

Anyway parts are $40 for temp sender (same as VL turbo)

brand new and O2 sender (same as VL turbo) is $90......

So i should be good again... Still got to map ECU again though

[Guest nismogtsx]

Ok.... They were wrong the car is still stuffing around...

The power is back, well sort of but now the car is leaning out

a bit and never used to go under 13:1........

It also miss's a little only noticable by hearing the exhaust...

It's also burning really bad due to smoke at rear when hammering

With the sensor unpluged theres no smoke and the car run's OK,

but misses a little still.....

With the new sensor connected its up to its old serging tricks???

Any thoughts, i have a booking at that place at the GABBA

where that really good turbo guy works but the best

i could do was next thursday.....

[Guest nismogtsx]

Ok so i have un plugged the water temp sensor that they fitted and the car idles perfectly... However the air/fuel ratio is very low... Also the car has a really hard time starting when cold...

Come on guys any thoughts????

I cant get it looked at until next Thursday....

[Guest nismogtsx]

*bump*

Had fun in the rain on the way home....