Powerfc - Idle Probs

[R31Nismoid]

What BOV are you using?

[T-u-R-b-O]

hi there,

i have a slight problem with my RB25... when i start the car and drive for a bit, reving it and everything else is just fine...

but i recently experienced this weird idleing issue... when the engine heats up (water temp >~80 degrees) the engine idleing revs begin to jump up down between 550-1100 rpm... ??? ... once when i was reversing into my garage it even stalled... it really sux having to keep the revs with the gas pedal in the >1000rpm area when standing at a traffic light ...

i tried changing the engine idle revs in the PFC to 850, but it still did it... should i maybe change the engine correction factor? or what other gimmic does the PFC pro offer that could influence that (dont have datalogit)?

or could it possibly be:

Faulty coils - not really since the engine revs good?

Faulty injectors - same as above

Stock BOV is replaced with a proper one

all hoses and other air hoses arent losing air

plugs are brand new

another maybe important thing to notice here, is that i noticed today in the dark garage, that when the engine does this 500-1000 rpm up and down, i saw that the lights from the tacho and headlights were also dimming as the revs changed??

any clue?

nico

[neo32]

there is idle water temp adjustment dont know how this works but mine was simlar got something to do with the cold start me thinks

[S13Deviat]

Battery on the way out???? Alternator not charging battery.... not to sure but considering your lights are dimming....

Maybe a bad 'earth' somewhere....

my 2c

[Guest Mashrock]

what are you using for the boost controler?

if your using something different from the powerfc's built in one it might be you still have it turned on.

i beleive i had similar problems with my gti-r..

[paulr33]

I've had this problem. copy the tune data, ETC, DATA INIT, YES, poweroff.

Perform self idle adjust and all will be well. Make sure u do it with warm engine, ie water temp at 80deg. As a last resort check airflow plug and wires and also look at SENSOR SW / CHECK when it idle hunts, see if anything is obviously out of whack or bouncing a lot

[T-u-R-b-O]

@R33Deviat: i was also thinking on the grounding issue... could well be the case... have to check on that...

@Mashrock: i just checked on that feature, and looking at pauls PFC FAQ, my boost thingy is off... also the 02 correction thingy is also off...

@paul: i was also thinking about that, but the prob with that is that i received a good map from a tuner, and inputed all 800 values for IGN & INJ with the hand-controller ... i just u know how much work that was... will try all other things, before doing this again

thanks everybody!

nico

[paulr33]

i know, its a lot of numbers to copy down. do you know someone local with datalogit? where are you located?

[T-u-R-b-O]

thats the problem ... there were no skylines imported into my county (Austria / Europe) and i am the only one who has an RB25DET in whole of western europe (except england and maybe a few crazy finnish people) ...

both are around 5.000+ kilometers away... have to do everything myself ... but the sound of the RB makes it all up

but thx for the offer

nico

[T-u-R-b-O]

i am using an apexi bov...

but could u explain how this can influence the idle only once the engine is hot and not the whole time?

is there a setting in the PFC pro that i can tell the engine to keep the same revs/parameters/corrections that are set when water temp is ~70 degrees , once i have gone up to ~85 degrees? this cannot be achieved by the REV/IDLE settings... tried raising to 890rpm, but engine runs at ~650rpm

thx,

Nico

Edited May 8, 2006 by T-u-R-b-O

[rob82]

Are you sure you dont have an air leak or a venting BOV? DO you have a catch can? Is the base timing set correctly?

[Bass Junky]

What about the Idle Air Control Valve?

Might be blocked and gunky........

You find this on the side of the throttle body....

[T-u-R-b-O]

@rob82: i have a good BOV installed and factory one is removed... i unfortunately don't have a catch tank and one of the pipes sitting on the camshaft cover (the one that "should" go into the air intake pipe, is open) ...

how can i check my base timing?

@bass junky: was also thinking bout this option, but wouldnt this then also effect the engine when it's cold...

just came back from a drive... car runs ok, revs ok, and idle is good as long as engine isnt hot... the moment i come of the highway and stand at a traffic light, the story with the revs between 500-1100 up & down begins again... even my tacho light was dimming again at low revs... also when i used other electrical components like the electric windows, the revs fell very low to ~300 and then up again...

appriciate your help...

Nico

[rob82]

@rob82: i have a good BOV installed and factory one is removed... i unfortunately don't have a catch tank and one of the pipes sitting on the camshaft cover (the one that "should" go into the air intake pipe, is open) ...

how can i check my base timing?

You have an air leak through you pcv system. Plug up the rocker cover vent or replumb it into the intake pipe.

[carl h]

actualy to me it sounds like a farked water temp sensor, when they go bad they cause erratic idling and poor performance.

the bad thing about them going south is that they do it slowly and intermitently, so while it might not happen when the car is 'cool' (still at operating temp but hasnt been driven) it will happen after a few spirited runs.

its worth a go and the sensor is cheap as (14$usd here) and it really does sound like that is the problem.

hope that helps...

[T-u-R-b-O]

ahaaa... you recon because its open by me, that this is causing the probs?

you can see on the pict which is the open one...

u recon that this is a possible reason that i cant boost more 0.5bar (acuator is good, and using blitz boost controller)?

thanks,

Nico

[T-u-R-b-O]

@carl h:

is there maybe an online site where i can get this sensor for that price?

thx!

[R31Nismoid]

The pic confirms as rob82 said.

His advice is what i would be taking