What are these?

[silvergsx623]

sorry no pictures yet... i'll give the best description i can.

On my 7mgte supra, under the intake manifold there are 2 "units". They have a brown 2 wire plugs that attach to each of them. They also have 2 vacuum lines that go to each of them. The "Units" appear to have an adjustment knob on the top/side of them. They hang below the knock sensors.

What are they and what do they do? lol thanks

If i need to post up some pictures, i'll do it tomorrow.

thank you very much for your time,
chris

 

[supraguy31]

Those are your VSV valves for your EGR setup. Just leave them alone as they are just for the Reason, Emissions.

 

[jetjock]

The "units' are 3-way solenoids. Toyota calls them VSVs for vacuum switching valves because both are plumbed to control vacuum. One is for the EGR system and connects to ported vacuum on the throttle body. It shuts the EGR valve off whenever the coolant is cold or the engine is above 4000 rpm.

The other solenoid is for the fuel pressure up system. It vents the fuel pressure regulator for about 2 minutes after a start when the coolant is hot. That increases fuel pressure and helps to clear vapor that has formed in the fuel rail during heat soaking when the engine has been off 30-60 minutes. That solenoid connects to manifold vacuum at the vacuum tree located at the front of the intake manifold. The "adjustment knobs" are filters to keep crap out of the solenoids.

Powder coat them and then let them be...

 

[supraguy31]

Yeah, As Jetjock Said. Some people run them and some People dont. I have both my VSV valve installed.

 

[cuel]

I wonder if some of those same people not running them are the ones that post hard start conditions when the motor is hot....

Powder coating, eh?

 

[supraguy31]

That would be a good Question. Ive always thought that if its there when the motor was built then there is a reason for it. I just put them back under there because thats 2 connectors that need to be Plugged in and I hate seeing loose connectors

 

[ms07s]

WOW I knew one was for the EGR but I had no idea what the other one did. I just assumed Toyota put it there for a reason and I should leave it be. Great info JJ!

 

[silvergsx623]

Ahh... ok!

Thank you guys for the info.

So would either of those "units" (3 way solenoids) being disconnected (electrical plug) cause the engine idle to surge? It is surging from 1000 to 1900 rpms.

I ripped the wire out of the front plug by accident. I'm going to look into fixing that tonight.

Thanks again.

 

[silvergsx623]

Ahh... ok!

Thank you guys for the info.

So would either of those "units" (3 way solenoids) being disconnected (electrical plug) cause the engine idle to surge? It is surging from 1000 to 1900 rpms.

I ripped the wire out of the front plug by accident. I'm going to look into fixing that tonight.

Thanks again.

well when i put the jumper on to go into diagnostic mode... the CEL just flashes, abut 1 flash a second.

Any idea on that?

 

[ms07s]

That means no stored codes IIRC.

 

[jetjock]

Ms07s: You're welcome. Fwiw much of that info is in the TSRM.

Silvergsx: The flashing (it should be once every quarter second btw) means you have no codes. It's a good thing. And no, neither connector being unplugged will cause that symptom although as cuel pointed out you may experience harder hot starts under some conditions if the FPU VSV isn't connected. As long as the fuel system maintains residual pressure you likely won't though.

 

[silvergsx623]

Ms07s: You're welcome. Fwiw much of that info is in the TSRM.

Silvergsx: The flashing (it should be once every quarter second btw) means you have no codes. It's a good thing. And no, neither connector being unplugged will cause that symptom although as cuel pointed out you may experience harder hot starts under some conditions if the FPU VSV isn't connected. As long as the fuel system maintains residual pressure you likely won't though.

ok cool,

Thanks for the help and info guys!

Got it back running, just need to adjust the timing and i have a few vacuum lines mixed up.

thanks again,
chris