Vct Not Working

[32vspecII]

hi guys

went to get my r33 dyno'd and it made a pathetic 207rwhp with hiflow turbo , z32 afm , 550cc injectors , pump and pfc

boost is good (15psi) and AFRs are good

they think the VCT is not working as they couldnt hear/feel the solinoid working .

on the PFC hand controller the VCT sensor check works as should if its not in idle or closed throttle , ie when accellerating in gear turns on and then off at about 4500

so question is how to check the VCT . Is sthe handcontroller check accurate or is this just saying the PFC is switching it on and off but not doing anything ?

also would no VCT make this much a difference ? basically hits about 5000 rpm and mokes no more power , a flat line (will post dyno tomorrow)

i would have though no VCT would make the midrange crap but leave the top end

[32vspecII]

forgot to add tomei poncams (stage 1) and exhaust cam gear set to 0

is there something we could have stuffed up when installing them ?

[Jem]

with the mods you've listed even with the vct failing to engage you'd still be expecting a hell of a lot more than 207 rwhp, and you're also right in that it would leave the top end alone, vct failing to engage leaves the intake cam advanced in the lower rpm, so it shouldn't effect the higher rpm..

perhaps when installing the cams / cam gear the timing belt was installed incorrectly leaving one of the pulleys retarded (as it's still making power down low)..

have you tried throwing more ignition at it in the power FC maps? if it is already on the brink of knock then i would say back off but if not it's worth a shot

ah well that's my 2 cents, hope it helps

[32vspecII]

with the mods you've listed even with the vct failing to engage you'd still be expecting a hell of a lot more than 207 rwhp, and you're also right in that it would leave the top end alone, vct failing to engage leaves the intake cam advanced in the lower rpm, so it shouldn't effect the higher rpm..

perhaps when installing the cams / cam gear the timing belt was installed incorrectly leaving one of the pulleys retarded (as it's still making power down low)..

have you tried throwing more ignition at it in the power FC maps? if it is already on the brink of knock then i would say back off but if not it's worth a shot

ah well that's my 2 cents, hope it helps

i have put 6 degrees of advance in it with global correction and it feels much nicer and shows no signs of knock at all

im pretty sure something is wrong timing related , I wouldnt expect to run that much extra and not show any sign of detonation

if felt like you could put double that in and she would be fine!

[RB30-POWER]

easy to check this in a couple of way.

1) get a 12v test light and connect it across the two terminals that plug onto the solenoid (disconnect the plug first of course) start car, rev it and off idle it should light up to indicate that the ecu is actually supplying a switching signal/power to the solenoid wiring plug.

2) get some small jumper leads with aligator clips (jaycar dse etc) with vct solenoid electrical plug disconnected still, connect each terminal to a 12V battery supply and earth, if you hear it make a loud click, you know its working mechanically also. if you do this with car running at idle you should hear engine change note as well, might run rougher with it powered up.

uncommon for that to fail however, more then likely the timing gears or belt is out a tooth or so, check cas timing once you have the belt on properly also.

[666DAN]

hi guys

went to get my r33 dyno'd and it made a pathetic 207rwhp with hiflow turbo , z32 afm , 550cc injectors , pump and pfc

boost is good (15psi) and AFRs are good

they think the VCT is not working as they couldnt hear/feel the solinoid working .

on the PFC hand controller the VCT sensor check works as should if its not in idle or closed throttle , ie when accellerating in gear turns on and then off at about 4500

so question is how to check the VCT . Is sthe handcontroller check accurate or is this just saying the PFC is switching it on and off but not doing anything ?

also would no VCT make this much a difference ? basically hits about 5000 rpm and mokes no more power , a flat line (will post dyno tomorrow)

i would have though no VCT would make the midrange crap but leave the top end

Was this related to the Slide hiflow, can we see the Dyno sheet please?

thanks!

[32vspecII]

uncommon for that to fail however, more then likely the timing gears or belt is out a tooth or so, check cas timing once you have the belt on properly also.

this is my guess too

[32vspecII]

Was this related to the Slide hiflow, can we see the Dyno sheet please?

thanks!

will post tomorrow

was with hiflow but i dont think boost drop is related to timing problems and with the same timing issues the gtrs is better everywhere in every way including hi end boost holding

[666DAN]

will post tomorrow

was with hiflow but i dont think boost drop is related to timing problems and with the same timing issues the gtrs is better everywhere in every way including hi end boost holding

Cool, just want to do a comparison with some other charts from the Stage 3 hiflow

[32vspecII]

vct/timing issues were caused by faulty CAS

no fuel pump is running out of push at 16 psi on gtrs so will need another tune with bigger pump and fuel reg

[niran]

hey guys i know this is an old thread but i need some help..

alright i got an engine conversion done a while back so im just going through everything in my car to make sure everything is and has been done right.. above in this topic it stated to check vct " get a 12v test light and connect it across the two terminals that plug onto the solenoid (disconnect the plug first of course) start car, rev it and off idle it should light up to indicate that the ecu is actually supplying a switching signal/power to the solenoid wiring plug."i used a multimeter instead and when i do this im not getting any voltage reading?

what could be the issue? is the solenoid meant to be on at low rpm(therefore giving a 12v reading), and then solenoid is meant to turn off at higher rpm(no 12v reading)??

any help appreciated

Edited January 24, 2010 by niran

[Don Dada]

More info on the conversion

Was it an entire swap?? Auto to manual?? What car?

Just to make sure.... you are testing the plug going to the solenoid right?

The nvcs activates at 1050rpm and deactivates at 4500rpm so give it a little rev to see if it activates.

[niran]

More info on the conversion

Was it an entire swap?? Auto to manual?? What car?

Just to make sure.... you are testing the plug going to the solenoid right?

The nvcs activates at 1050rpm and deactivates at 4500rpm so give it a little rev to see if it activates.

hey man

sorry should have said all that.. it was an r32 gts-t manual originally and we put a rb25det s2 engine and manual gearbox in(using s2 loom also). yep its the vct plug i removed. i also double checked as one off the wires when i looked at the colours and matched it up to the ecu pin out it said Variable timing control solenoid (pin #113). The other wire on that socket is a blue/white, when i looked in reference to that on the ecu pin out it says Control unit power supply (pin #49)..

i also did what you said i revved it to about 5000rpm and no noises from the solenoid itself.

When i checked the blue/white wire for power, i did this by attaching the positive end off the multimeter to the blue/white wire and the negative end off the mutli meter to a ground however i get no voltage.. but if i connected the negative terminal to the blue/white wire and then connect the positive side off the mutli meter to the car's positive terminal on the battery it reads 12.8 volts.

Cheers, niran

[r32u]

was told there should always be power to the plug as the ecu opens the earth to complete the circult

plus does anyone know if there has to be a speed signal for it to work

[JonnoHR31]

no there doesnt have to be a speed signal

[paulr33]

make sure the car is in gear (clutch in) VCT wont fire when the car is in neutral on the manual GTST (NTR is the switch)