Clickong Noise From Vct Solenoid

[NICKCEFFY]

Hey guys,

hopefully somebody might be able to help me out here, over the last couple of track days my rb25 180 has felt slightly underpowered on some laps but then others felt ok. so looking under the bonnet i can here the solenoid for the vct cam on the side of the block, with the plug and two wires coming off of it, clicking on and off (presumably) even while the car is idling.

Would this be causing some of the issues with lack of power, i.e not switching the cam properly and would it be a simple fix of replacing the solenoid or is it something alot more involved than that like wiring or the actually cam

If someone has some leads or ideas that i could try that would be heaps appreciated

Cheers

Nick

[JonnoHR31]

unplug it and see if your power stays consistent. it normally turns on just off idle then off at ~4500rpm but if its somehow randomly switching at higher revs it could be robbing you of some power

[NICKCEFFY]

Cool, i'll try that, but is there any reason why it would be constantly clicking while on idle?

[GTSBoy]

One of several things could be faulty. 1) the solenoid itself is bung. 2) the ECU is bung. 3) the wiring between them, or the power to the solenoid, is bung.

Given that it should not be engaged at idle (ie while you stand there with the bonnet up), I'd be leaning toward the ECU being bung, which is not a good thing.

[NICKCEFFY]

ah shit! no worries will go try the first few and hopefully it works before i get to the ecu

[DVS JEZ]

Are u only basing ur diagnosis on an intermittant loss of power on the track? Is it only inbetween 1500 And 5000rpm where its slower?

[NICKCEFFY]

well basing it on its definately alot doughy-er in low revs (not 100% on actual revs as i don't have a tacho) but more worried with the pretty much consistant ticking of the solenoid, which has lead me to believe that it is an issue with the VCT.

I've done a compression test (approx 158-9 across all six) all clamps and silicon joiners have been checked, air flow meter checked for cracks and leaks (its located in the cool side of the cooler pre throttle) and spark plugs were only done recently

Cheers for any help though

Edited January 24, 2012 by NICKCEFFY

[DVS JEZ]

While its clicking check that the power is constant at the solenoid.

Use a test light connected to the positive terminal and check if the negative is flickering on and off causing the solenoid to switch on and off.

If the negative is flickering at the plug check at the ecu plug to see if its a wiring fault.

Then if its still an intermittant signal it may be something like neutral switch etc playing up. Need to check all before replacing ecu

[NICKCEFFY]

awesome cheers mate, much appreciated!

[JonnoHR31]

have you tried driving it with the vct unplugged then straight away again with it plugged in yet?

[NICKCEFFY]

Nah haven't been able to try it due to it being track only and the driveway isn't quite long enough, lol! the first time it started happening we thought it was fuel issues, but have since rebuilt the fuel system and then the second time was the last event of the year and spent most f the time diagnosing every thing else but only just sort of connect the dots when we heard the clicking. it was most likely happening all the time but during the competition it wasn't some thing we were looking for so didn;t really take note of it

[LANDSCRIBBLE]

Old thread i know but im having the exact same issue with my freshly rebuilt rb25det. Seems to be only while idling I can hear and feel the VCT solenoid clicking every few seconds causing it to hunt all over the place and eventually stall.

When i unplug the VCT solenoid connector it idles smoothly, no hunting or stalling.

I cant be 100% sure but it felt like there was a little more grunt in the bottom end with the VCT connector on = VCT works? (I have to baby it around)

Running a vipec v44 plug in ECU, was wondering if having no battery connected for a few months would cause the ECU to reset?

Anyway, I'll try those things tomorrow.

[DVS JEZ]

If the idle is higher than it should be this can happen.

Also the tps may need to be recalibrated

[GTScotT]

I'm fairly sure all that's between the ecu and the solenoid is the main 12v circuit and a control wire direct from the ecu. That being said I doubt there is an actual problem with the wiring or the solenoid itself. Most likely a calibration issue as mentioned.

[LANDSCRIBBLE]

Ok ill have a fiddle with the idle speed. By adjusting the tps, you mean loosening those 3 bolts and rotating it a bit?

[GTSBoy]

Yeah, you need to set the voltage it returns to the ECU to be about 0.4 - 0.45 volt.