RB25, possible VCT issue?

[MatthewT85]

So installed xspurt 1000cc top feeds with top feed rail from scotty, Hypergear ss2, int gated, Haltech platinum pro, return flow cooler

Now when I had it tuned it made 281rwkw @17psi but full boost was somewhere at 5400 when I mentioned that it should on sooner the tuner had said there was something odd with the VCT when he was trying to set it, he thought it could have been a timing issue, so I had him check that(it was all fine) he then later contacted me and said it was the wastegate not set correctly, set it and then sorted the mid range, boost at 4400.

Now everything I've seen about the ss2 can have full boost at around 3800rpm, so it now has me wondering if there could actually be an issue with the VCT itself.(if VCT can help boost come on)

So have been searching on here about VCT and looks possible that my VCT is stuck as its giving me good top end but possibly poor low....

I disconnected the VCT and drove it and it feels the same, but I am unsure if it feels the same because it was faulty before hand and has been tuned around it...

The plug itself needs replacing as it doesn't clip on, I used a multimeter at the plug, car on, positive on one pin and neg on chassis and then other pin and chassis and no change at multimeter.  Did it hot and cold if that makes a diff.  Have I done it right? I assumed the positive wire was constantly on and neg switches on/off , so at least one of the pins would be giving me voltage.

I have to take the car back at some point to sort something else out but just want to see if there is anything I can do to ensure its working or not.

 

Edited July 15, 2016 by MatthewT85

[KiwiRS4T]

Take the VCT out and wire it directly to see if the actual solenoid works first.

[Dose Pipe Sutututu]

is the Halaltech set correctly?

put a multimeter on and rev the car, it should register a voltage change at a specific rpm point (as per your tuner's settng)

[hypergear]

Check and make sure the internal gate is 3mms preloaded. With active vct, you should hear a click on throttle movement

[MatthewT85]

7 hours ago, Dose Pipe Sutututu said:

is the Halaltech set correctly?

put a multimeter on and rev the car, it should register a voltage change at a specific rpm point (as per your tuner's settng)

ill have to check if its set correctly. it should activate just off idle and deactivate around 5k? correct?

when i rev the car it has to be in gear? another thread i read said it didnt activate without it in gear or something

4 hours ago, hypergear said:

Check and make sure the internal gate is 3mms preloaded. With active vct, you should hear a click on throttle movement

yeah thanks the gate is set to roughly 3mm

8 hours ago, KiwiRS4T said:

Take the VCT out and wire it directly to see if the actual solenoid works first.

when you say take it out, do you mean take the vct solenoid out of the head and wire it directly to a battery? Also does it matter which pin is pos and which is neg?

[KiwiRS4T]

3 hours ago, MatthewT85 said:

ill have to check if its set correctly. it should activate just off idle and deactivate around 5k? correct?

when i rev the car it has to be in gear? another thread i read said it didnt activate without it in gear or something

yeah thanks the gate is set to roughly 3mm

when you say take it out, do you mean take the vct solenoid out of the head and wire it directly to a battery? Also does it matter which pin is pos and which is neg?

Yes. No it doesn't matter which way round.

[MatthewT85]

So I've tested the solenoid and it's clicking. Next thing I'm gonna do is cut and solder a new plug on as it isn't staying attached and might be the issue.

Stupid question though. As I have to solder extra wire on so it still reaches the plug I went to buy some.
The wire had 10 amps on it. Other option was 25 amps. Is the 10 amp wire ok to use?

[Dose Pipe Sutututu]

are the set points set correctly on the Haltech? because there's a vac and +ve pressure values that needs to be set.. conenct up the Haltech and press F4, then look for the VCT tab.. I recall it being on the OUTPUT menu, grab a screen shot.

[MatthewT85]

are the set points set correctly on the Haltech? because there's a vac and +ve pressure values that needs to be set.. conenct up the Haltech and press F4, then look for the VCT tab.. I recall it being on the OUTPUT menu, grab a screen shot.

Yeah it wasn't set up as it looks like it wasn't working when I dropped off my car.
So I'm gonna attach a new plug and hopefully that's the issue.

[MatthewT85]

So this is what it's at atm. What I'm trying to do atm is just work out it it's the settings that's been missed. Or whether I have an issue with the wiring.
I just want to make sure it works so it can be.put on the dunno to be set correctly

[Dose Pipe Sutututu]

set both on points at 1200rpm and max load at 250kpa or 300kpa

[Dose Pipe Sutututu]

also minimum TPS of 10% just to be safe

[MatthewT85]

thanks, 

will it be ok to drive around with the altered settings?

also if i wanted to test the voltage at the plug after changing the settings, would i just have the car idling at operating temp and use a multimeter, or do i have to have someone put it in gear and clutch in?

[MatthewT85]

I have just looked at an old thread of yours johnny and someone suggested having the car at idle and applying direct power to the solenoid using a battery or something to see if the idle changes, could this be a good test to try before playing with the haltech settings?

[Dose Pipe Sutututu]

your Haltech settings aren't ideal anyway

If you want to test, I suggest this..

set the TPS to 5%, operating temp from 50c, set point at 1000rpm on both vac and boost then hold the revs about 2k and get someone to pull off the plug see if there's a change on engine note.