Pfc And Strange Ignition Retard Issue .

[89CAL]

Ah yes I didnt see he was looking at TPS on datalogit, yeah data aquisition for monitoring is pretty slow on FC-Edit

[discopotato03]

I never use the game boy gadget , not real flash if the Datalogit interface is that slow . I was thinking the same about if the PFC was that slow how could it work .

So , how old is the hardware in these Power FCs ?

A .

[t_revz]

So I turned my tps to .51 and tested it out yesterday. With the engine off the throttle light doesn't come on at all with throttle changes. Starting it up it comes on at .57 I could move the throttle from .51 to .54 usually without rpm increasing then picks up from there. Getting up to .56 idle is slightly higher but still sounds fine. Going to .57 and the engine cuts out almost immediately but timing was still above 10. If I got off the pedal quick enough it would drop to 300rpm and 3-4 degrees and recover. Going past this point to .65 didn't have any problems but seems gutless when trying to take off and the more rpm comes down the worse it got.

Since I saw it stall a couple times but timing hadn't dropped I'm wondering if my fuel setting are too rich. I didn't know till after it was tuned but the intake cam was 6.5 degrees retarded and exhaust was 3.5 retarded. Both now are 0.25 retarded.

As I read that fuel settings of 100 are close to stoich I would have thought my idle area would all be 100. But my fuel 4x4 settings are

119.119.119.114

119.119.117.112

114.114.106.103

110.110.100.100

Are these too rich or not uncommon?

For timing its

18.18.18.26

18.18.18.26

18.18.28.33

18.23.30.34

[mico]

I have this issue too. Wot is perfect but light throttle or slowly building boost, especially around 4k it misfires and stutters badly. Sometimes at low rpm too. It's not vaccuum to boost transition either its on boost. Sucks when u come to a hill and all u can do is go wot.

[DVS JEZ]

I have this issue too. Wot is perfect but light throttle or slowly building boost, especially around 4k it misfires and stutters badly. Sometimes at low rpm too. It's not vaccuum to boost transition either its on boost. Sucks when u come to a hill and all u can do is go wot.

Get the tune checked.

Also try turning off 02 feedback, may be an issue if the sensor is faulty

[mico]

Thanx no sensors btw

[t_revz]

At work today changing final drive oil in a haul truck when BAM, a lightbulb goes off in my head and I facepalm myself. I bet the light on my hand controller for throttle isn't throttle and is actually VCT.

I get home and check the Powerfc FAQ and yep VCT is VTC on the controller. Can't believe I didn't realise earlier. So VCT is stalling the engine at just off idle and prob explains why its also gutless for the next couple hundred rpm but its fine above 1500.

Tomei spec for cams is 120' inlet and 115 exhaust. They were 126.75 inlet and 110.5 exhaust before I adjusted them back towards spec. Fark me

[t_revz]

Called tuner today who said I'm prob running to lean around idle and needs fattening up now cams are dialled in. I thought about getting an rpm controller for switching VCT higher but he said it shouldn't be neccasary. I'm gonna try fatten it up a little and see how it goes shortly as I won't get to the tuner for a month or more. Or I'll disconnect VCT if necessary.

[GTSBoy]

Is not VCT switch point adjustable on the PFC?

[89CAL]

switching VCT Off higher in the rev range? Power FC will do this if thats what your talking about

If not then disregard this message

[t_revz]

Switching it ON higher?

There's no option on the hand controller. Can it be done with a laptop and software.

[89CAL]

It only has a switch off point. It comes on at low RPM when it has met certain criteria from memory. if you stab the throttle you might hear it click but if you hold it on 1200rpm or so it will possibly be on then switch off as there is no load

The point of VCT is to increase low down torque so you want it on as early as possible, The Power FC has an off triger only for this reason

I think in your case you want to turn it on later for troubleshooting however?

[t_revz]

Yeh I'd like it on at 13-1400. But hopefully turning fuel numbers up in the top corner might overcome this enough. Ill try check it Friday or Saturday.

[discopotato03]

So does this mean you have a potential overlap of VCT off on and user set fuel cut resumption in the same area and the two fighting each other and screwing things up ? It sounds like off idle VCT on is something else Apexi and Datalogit may not give us any say in .

Cam timing is something I should look into because I'm using those as well .

A .

[t_revz]

He thought from what I said on the phone that I may have increased dramatically how much its breathing by dialling the cams and now its lean. By richening it up it will be more stable as VCT enables.

I have 256 poncams plus intake was 3 degrees more retarded than exhaust reducing overlap. But now I've advanced them both, more so intake.

I offered to get an rpm switch to control VCT but he was pretty confident he can sort it on the dyno.

[paulr33]

as the others have said you cant change when VCT comes on, but you can set when it turns off

from memory

car must in gear

TPS must be open

NTR must be closed

RPM must be more than 1300rpm i think

before VCT will fire (the VTC switch will have a black dot)

to test the theory, start car, clutch in, hold clutch in, move into gear, keep holding clutch, rev in while holding clutch

PFC will think you are in gear, it will see TPS and NTR and VTC should fire

all you can do is disable VTC completely or change the kick off point, you cant change the kick on point

form memory its like between 1300rpm and 4500rpm (rb25 default)

so you could do like 1300rpm and 1350rpm if you wanted using datalogit to edit it

[paulr33]

[89CAL]

My VCT seems to work in Neutral

My NTR dot never changes though so maybe my Neutral switch doesnt work

[GTSBoy]

Dead neutral switch is very common.

[t_revz]

My VCT seems to work in Neutral

My NTR dot never changes though so maybe my Neutral switch doesnt work

+1

My neutral switch has been unplugged for 10 years now as it somehow used to bring my reverse lights on.

Once at operating temp its on at 1000rpm