Greg_Canada

Hi guys, one of my EVAP sensors is clicking when the engine gets warm, see this video.

http://www.youtube.com/watch?v=9YDutPdmfP0

If i unplug the vacuum lines it still clicks. Only if i unplug the harness it stops. When i hit the throttle it stops clicking. Sometimes when cruising it begins clicking again.

Anyone know whats up with it? Is the sensor bad? I haven't driven it since last year (been working on other stuff) but i remember seeing some code for EVAP high flow or something...
Any ideas?

Thanks,
Greg

j2the-e

What solenoid is that? You are describing the normal operation of a purge valve, but that does not look like a purge valve. That connector should go to your purge valve- the one that is made for the 3.4 engine

Greg_Canada

When installed in a 3rd gen it is mounted on the EVAP canister.

j2the-e

That is the vapor pressure switching valve. One line goes to the canister, one line goes to tank pressure, one line goes to the vapor pressure sensor. Not sure which goes where, but look at a vacuum diagram for any newer 3.4 with the canister under the hood. The wire you have hooked up to it is supposed to go to your purge valve. That is why it is clicking. The purge valve is supposed to click like that. The purge valve has 2 larger hose going to it. One will go to your canister and one will go to the intake. I'm not sure how to make it all work with an old canister so it wont throw a code though.

Greg_Canada

The purge valve is not the valve that is clicking, it is fine... it's the VPS that is clicking... i will re-check my vacuum routing...

Thanks

j2the-e

Yes, I know that. That is why I said you're wiring is incorrect. A purge valve is supposed to do EXACTLY what you are describing, which means, you have the wires for the purge valve hooked up to the vapor pressure switching valve( not the vps-big difference.) The vps has only one vacuum line.

hamish_18

damn I have gone through 4 swaps now and two of the customers have complained about the ticking. I was hoping this thread said how to stop it. I know it's normal, but it sucks when you can hear it in the cab so easily. I have tried to use rubber mounts and everything.... But the above post is correct. the Purge valve with the 2 larger hoses should be the one clicking. you can even feel it when you hold it. If it isn't then you have your routing wrong. I printed out the diagram from this post. It hasn't caused any CEL's ever.

https://www.yotatech.com/51359966-post760.html

Greg_Canada

I just checked the hose routing, and it's exactly like it says to do in ORS's instructions.
Maybe i'll try another sensor....

Also i'm unsure of what you mean with "your wiring is incorrect"... i used a brand new OEM wiring harness...

j2the-e

Pay attention...The connectors for the vapor vsv (the one thats clicking) and the purge vsv (the one that is supposed to click) are interchangeable. Your wiring is wrong. Switch the connectors and your problem will be solved.

Greg_Canada

I will give it a shot when i get home, thanks!

ORS

The above mentioned fix is correct. The wiring itself is not incorrect, the connectors on these items in questions are connected improperly. As said, the purge valve and vapor pressure vsv connectors are identical. In a custom setup it is very easy to connect them improperly.

As mentioned above, the purge vsv will make a clicking sound; it is a 'duty solenoid', meaning it is rapidly turned on and off by the computer. The speed at which it is switched on and off ultimately determine how much volume is allowed to flow through the valve.

In the OEM setup the purge vsv is rubber-mounted to the canister then to the fender, so the noise is well isolated from the cab. In a swap this valve is often mounted so the noise is not well isolated. It simply needs to be more isolated from the cab by rubber mounts or position, so it does not annoy the driver.

Also, the above mentioned EVAP diagram works well for swaps into older Toyotas. It can also be found on our website, in the tech section, included in the 3.4L conversion instructions.

I don't think I stated anything new here, I just wanted to affirm the good advice above.

Greg_Canada

Swapped the wires today... mint!
The correct sensor is clicking... it's very quiet, cant hear it unless i stick my ear beside it or "listen" for it... engine sounds like it's idling smoother too...
Thanks alot!

mt_goat

This was my solution to make it quite (silicone rubber stuff wrap):

JedidiahParker

I have a 1996 tacoma 2.7 and mine has 3 vsv with the same connectors 1 is down in between where the air intake goes into the head and then there is another one that looks identical but has bigger hoses and it is near the charcoal canister. The 363rd vsv has the same connector but looks totally different but it is correctly on the charcoal box. The vsv with the larger hoses was clicking so I switched the connectors to the odd looking vsv on the charcoal box and now I do not hear any clicking. However I don't know if that is the right thing to do.