[T.F.S.]

hi

stockish GTR, jap chip

AFR seems to be really high at idle and part throttle, i have seen 12.0/1 at idle and worse on rundown

can someone just confirm that AFR is 14.5 at idle on a well running GTR when warm?, it seems to warm up right from cold.......AFR 15.0/1 but when its warm this just seems to go mega rich

lambdas need replacing maybe or they could even be disconnected from the ECU?, would this throw a code up?

regards, brian

 

[GTR26R]

15 : 1 is lean not rich, its 15 parts of air to 1 part fuel.

 

[T.F.S.]

yes i know that

its the 12.0 at idle that concerns me not the 15.0/1 during warmup because the rich condition causes borewash

 

[R32 Combat]

As a reference, my car
Idles @ 13:1
On cruise its 14.7:1
WOT its 11.5:1


Usually cars should idle and cruise @ 14.7:1

 

[T.F.S.]

As a reference, my car
Idles @ 13:1
On cruise its 14.7:1
WOT its 11.5:1


Usually cars should idle and cruise @ 14.7:1

thanks mate!!!

mine is also off the scale rich lower than 10.0:1 at WOT

it does not use the lambda sensor at WOT though so why should it be so rich compared to yours?, i take it yours is stock or chipped ECU and not a remapped PFC or the like? (which we may expect to see leaner conditions on?)

Idles @ 12:1
On cruise its 11:1
WOT its <10:1

 

[R32 Combat]

My ECU is programmable, hence me being able to chose the AFR's I like.

It sounds like your fuel pressure regulator has been moddod. Does it look like the top has been pushed in?(to alter the spring rate)

 

[R32 Combat]

What setup are you using? Injectors, ECU, FPR etc..

 

[T.F.S.]

looks stock, the fuel pressure at idle is 3.5bar..

ECU is a nissan remanufactured ECU with a STORM chip ("tokyo power base" it says..)

injectors "look" stock?

i rebuilt it but i know nothing about the engine management side, thanks for helping!

 

[T.F.S.]

shit, sorry wrong pic

 

[kismetcapitan]

What setup are you using? Injectors, ECU, FPR etc..

I'm guessing your ECU uses wideband lambdas, therefore making your AFR readings reliable? I'm mulling over this particular issue now - I want wideband accuracy in my car, but I don't think the Apexi Power FC supports it (not sure on that), plus I'd like to drive an A/F meter with a wideband...meaning I might have to add a bung or two to my downpipes...?

 

[T.F.S.]

i use the stock lambdas for the ECU and a wideband for a readout that does not go to the ECU (just displays the infomation in the cabin)

my AEM wideband has a facility to output the voltage to the ECU in narrowband format but this would only be one sensor for both banks and i assume the ECU can correct just bank one if need be, my wideband would give an average for both cylinders which would be a disadvantage?

(i have one at the sensor just before the cat, ebay do cheap bungs)

i guess for best results you would use two widebands but this would be expensive and TBH i have so many gauges now i cant look at them all lol

 

[R32 Combat]

With the PFC datalogit, you can log AFR, but the ECU won't do anything with it.

 

[T.F.S.]

so can someone confirm that fuel pressure as stock is 3.5 bar at idle please?

 

[R32 Combat]

Yes, I think its close. Mine is set to 48psi, which is 3.3bar. 3.5bar is 50psi.

I think STD is 48psi

 

[T.F.S.]

thanks

 

[[email protected] M/S]

3.0 bar with no vaccumm.

 

[T.F.S.]

3.0 bar with no vaccumm.

:thumbsup:

 

[T.F.S.]

it seems that the car isnt going into closed loop, disconnecting the lambda sensors results in no change to the fuelling

ECU loom looks like it has a few spliced conections on it from a piggy back ECU that was once fitted and then removed, may just be a misplaced wire hopefully

 

[tweenierob]

3bar standard pressure....

With vacumn off.

Rob

 

[T.F.S.]

i had a look at the wires going to the ECU..there was no voltage present at the ECU clip from the lambdas (pin 29/55)

i have a AEM wideband that can output a narrowband sigina lso i tried feeding this to those pins but there didnt seem to be any effect to fuelling

i guess this looks like an ECU fault?