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How Do I Know That Vct Is Working

niran

By niran,
in Engines & Forced Induction

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niran Proficient

niran

Posted
Posted

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

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blind_elk Grand Master

blind_elk

Posted
Posted

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?

paulr33 Grand Master

paulr33

Posted
Posted

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

PM-R33 Grand Master

PM-R33

Posted
Posted

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.

niran Proficient

niran

Posted
  • Author
Posted
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

niran Proficient

niran

Posted
  • Author
Posted

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

Jaysiin Enthusiast

Jaysiin

Posted
Posted

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

niran Proficient

niran

Posted
  • Author
Posted
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...

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