Power FC idle

[Guest KILLER-T]

I need help from someone that is clued up on Power fc's.My car has a real bad hunting problem at idel it has done it since i put the power fc in my car and its giving me the shits.I had a read of the FC manual and it has a idle self learn mode it goes into after the ecu is first installed can i get the ecu back into this mode by unpluging and then pluging it back in.It has to be something with the ecu because i put a new afm in and it still does it and if i plug a stock ecu in and it idels fine

[GTS-t VSPEC]

Hi Killer,

Have you had a look at the TPS position, mine tends to float a bit and this can cause hunting, might be worth looking at.

See'ya:burnout:

[400HP]

Have you had it tuned yet?

[Sydneykid]

Hi Killer, in the PFC the AC, power steer and electrical load are all settable. I have seen a couple where the AC on is set lower than AC off. Check them on the Commander in the Settings menu.

For other tests, select the set up menu on the Commander and monitor in real time the outputs from the sensors. While the engine is surging you should see illogical changes in one (or more) of the sensor outputs.

If that all looks OK, then I'd check the low rpm areas on the ignition and fuel maps. I have seen one with a rogue number (very rich) in the fuel map and this made the engine idle unsmoothly whenever it was at that particular load point.

Hope that helps.

[400HP]

Hi Killer, in the PFC the AC, power steer and electrical load are all settable. I have seen a couple where the AC on is set lower than AC off. Check them on the Commander in the Settings menu. 

For other tests, select the set up menu on the Commander and monitor in real time the outputs from the sensors. While the engine is surging you should see illogical changes in one (or more) of the sensor outputs. 

If that all looks OK, then I'd check the low rpm areas on the ignition and fuel maps. I have seen one with a rogue number (very rich) in the fuel map and this made the engine idle unsmoothly whenever it was at that particular load point. 

Thanks for the input but if the powerFC is re-initialised then all this should be default right?

When you say you've seen these thigns surely it must be on preset or second hand PFCs?

[Steve]

does it hunt when you start up, or only when coming back from revs - eg when slowing down. I had this problem - two things caused it. At idle, it was vacuum leaks - really small ones, check your hose clamps and visually check all hoses that come off the plenum - I found many, clamps that were a bit loose and old deteriorating hoses, replaced them and all is good. I think the power fc may be a bit sensitive.

Secondly I had trouble coming back from revs. This was to do with the idle being incorrectly set and the accelleration fuel cut recovery rpm being incorrectly set.

These settings worked on mine (sorted the problem out)

Idle ac off : 700

Idle ac on: 710

Decel...ac off: 1100

Decel...ac on: 1300

Just a couple of other things to check.

[Guest KILLER-T]

Ok i cheked all hoses and no leaks i will try your settings for my idle will get back to you after lunch and the tps allways reads the same voltage

[Guest KILLER-T]

One thing i noticed is i only have to move the gas peddal about 3mm and i hear this click noise i think it is the vvt kicking in is it ment to kick in so early

[GTS-t VSPEC]

Killer,

That won't be the NVCS kicking in, does it do it when your stationary or just moving?

See'ya:burnout:

[Guest KILLER-T]

it must be if its sitting there @ idle and i move the butterfly just a mil or two it clicks and when i return it back to idle it clicks again.The clicking noise is comming from the left hand side of the engine just infront of the injectors.It has a plug with a brownish end on it i will take a pic and show u that might be the easy way:uh-huh:

[400HP]

Also when we were doing a friends powerFC... it was showing check engine light and giving all sorts of hassles until we disabled the Electronic boost control option.... dunno if this helps

[whatsisname]

Originally posted by KILLER-T

it must be if its sitting there @ idle and i move the butterfly just a mil or two it clicks and when i return it back to idle it clicks again.The clicking noise is comming from the left hand side of the engine just infront of the injectors.It has a plug with a brownish end on it i will take a pic and show u that might be the easy way:uh-huh:

The click you're hearing is indeed the VCT solenoid (on @ 1400rpm - off @ 4500rpm from memory?) VCT on the RB25DET is for low/mid range torque. The solenoid & plug is as you described it, mounted behind the inlet cam gear on the LHS of the motor.

[GTS-t VSPEC]

Killer-T,

Your not talking about the factory fuel pressure reg. are you?

See'ya:burnout:

[Guest KILLER-T]

sorry about the quality of the pic its was taken with my phone

[GTS-t VSPEC]

Killer, Could you make the pic any smaller?

I'll go out and have a look at my car to see what your pointing to.

See'ya:burnout:

[GTS-t VSPEC]

OK, I had a look and the thing with the redish connector is the Variable cam timing pickup (I think). If your car is idleing and you give it some throttle have your hand on this to make sure that is where the noise is coming from.

Does it appear to be loose?

I've never heard of one of these breaking before, but it might be best to take it to a tuner to ask if it's safe to remove and have a look at it.

See'ya:burnout:

[whatsisname]

Trust me here guys the item your talking about IS the VCT solenoid If you free rev' the motor in neutral @ 1400rpm you'll hear it turn on, "CLICK", then as the rev's drop below 1400rpm you'll hear it "CLICK" again as it turns off. I've had a small test globe connected to the VCT plug & watched the light go on & off to see what it was doing.

[GTS-t VSPEC]

So that is normal then, it's the solenoid making the clicking noise?

My car is so noisey I must never have noticed before.

Killer, Back to the drawing board, I didn't think that would be the problem. Where did you have it tuned?

See'ya:burnout:

[Guest KILLER-T]

ok so we know its the vct kickin in at 1400rpm like it should so its not that any thing else i have a few odd numbers on my commander eg. this is my inj map

99 / 99 / 99 / 101 / 102 / 103 / 101 / 100 / 100 / 101 /

103 / 101 / 100 / 115 / 119 / 125 / 125 / 125 / 125 / 125 /

line 2

99 / 98 / 90 / 90 / 90 / 90 / 90 / 90 / 90 / 90 /

90/ 90 / 90 / 90 / 90 / 90 / 90 / 90 / 90 / 90

and it repeats this untill line 8 and then the numbers start increasing with every new line

i cant undersand why the numbers should be so high on the first line :confused:

[whatsisname]

Originally posted by GTS-t VSPEC

So that is normal then, it's the solenoid making the clicking noise?

Yeah it's reasonably loud, if you aren't listen for anything in particular you'd probably never notice it, if you are then you'll hear it for sure. Next time you start your car bring the rev's up over 1400rpm & then back to idle, you'll hear it.