Jump to content
SAU Community

Recommended Posts

hey everyone

i know there is a few threads on vct not working, i have read through them all and tried the solutions however i need some more help.

the car i have is a r32 gts-t with an rb25det conversion. I had it done by a mechanic and after i brought it home i thought i would just do some searching as my car felt a bit sluggish down low. going from a 2 litre to a 2.5 litre i thought there would be more response.

so i searched through the forums and got the the vct issue, my first question is, is the vct meant to be always on between 1500rpm-5000rpm hence there's power at the solenoid terminals? or is it the other way around the reason im asking this is because im getting mixed answers and i cant solve the problem without knowing exactly which way its meant to be on/off.

the next problem is ive never owned a r33 s2 so i dont know what vct is meant to exactly feel like or even what a r33 should drive like (engine wise). basically what happens at the moment with my car is.. say i am in second gear at 2000rpm cruising speed if i put my foot down all the way, it slowly starts moving up in the revs when i hit about 5000rpm my engine note changes and i get a sudden pull and then the car builds up speed reasonably quickly. does this mean my vct is not working? as my low end is sluggish.

also i checked using a multimeter, i think ive done this right however if i haven't please let me know. i removed the connector off the solenoid and got a mutli meter, set it to dc voltage and connected the positive to one off the pins on the connector and the negative to the other pin on the connector. i then got some one to sit in my car and rev between 1500rpm-5000rpm but yet i got no voltage being displayed on my multimeter.

next i thought maybe the wires weren't going all the way to the ecu and there could be a broken wire so then i pulled out the ecu found pin #113 then connected one side off the multimeter to that pin and the other side to the light green wire on the solenoid side off the connector and it beeped hence there was continuity. next i checked the other wire and found that it beeped when i touched pin # 49 (control unit power supply).

so finally what does this mean as i am lost for ideas?

any help appreciated

thanks guys, niran

Link to comment
https://www.sau.com.au/forums/topic/306301-how-do-i-know-that-vct-is-working/
Share on other sites

The ECU will switch the solenoid to earth. Which ECU are you using?

Check for +ve at the solenoid plug - one side of multimeter to plug, other side to earth, ign ON.

Also, drive around with the plug disconnected - can you feel a difference in performance?

if VCT is off (ie in your case) the car is sluggish and performs like ass until past 5000rpm

VCT will engage if

RPM < 1800rpm and RPM > 4700rpm

and

Gearbox is not in neutral (ie NTR switch is off)

so check basics, if i unplug mine or disable it, the car is sluggish as all hell until 5000

Paul is right, the car has to be in gear when giving it throttle if you want to use the multimeter on it (hold clutch in, give it revs). This is probably why you aint seeing anything on the multimeter, because you are revving it in neutral.

The ECU will switch the solenoid to earth. Which ECU are you using?

Check for +ve at the solenoid plug - one side of multimeter to plug, other side to earth, ign ON.

Also, drive around with the plug disconnected - can you feel a difference in performance?

hey man the ecu i am using is a manual r33 s2 well thats what it says on it. i attached a photo also

post-44649-1265005547_thumb.jpg[

if VCT is off (ie in your case) the car is sluggish and performs like ass until past 5000rpm

VCT will engage if

RPM < 1800rpm and RPM > 4700rpm

and

Gearbox is not in neutral (ie NTR switch is off)

so check basics, if i unplug mine or disable it, the car is sluggish as all hell until 5000

hey dude, alright i took it for a drive first with it plugged in, then i removed the connector and drove it. to me i feel no difference in acceleration :D

so this means my vct is not opperating ?

thanks, niran

hey guys

i finally got the vct working.. ended up buying a bulb, soldering it to two wires, then the other side off wires put some small spade clips and plugged it into the vct socket. Took the bulb through the firewall and left it on top off my dash, took it for a drive and the bulb didn't turn on. so i changed one off the bulbs wires to 12v+ and left the other side off the wire connected to the lime green wire which connects to pin 113 on the ecu. Took it for a drive and yahoo!! bulb turns on from 1500-4800rpm then turns off.

Ended up getting an ignition source and cutting off the old power wire to VCT and then soldered the new power wire.. took it for a drive and runs awesome!

thanks for all your help guys.

Niran

hey, my car is exactly the same. i thought the vct kicked in at 5000rpm-ish as low end is lame. though...

1. i dont know what rb25det vct feels like.

2. i thought it was the lack of torque going from a rb30et to a rb25det so i ignored it

so maybe, maybe my vct is not working as well. saying that when i got it dynoed while back i still was abled to pull off 180+rwkw and 400 or so nm of torque.

will the vct affect the peak power/torque or just the curve of power delivery?

any tips feel free to pm

good to hear you got it working niran

if you dont have working VCT your car will run like ass

you really should get it working

thanks man :P. its great now that vct is working.

cheers for the help

  • 8 years later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
×
×
  • Create New...