Questions on the two vsv's under the intake

[gaboonviper85]

Question #

1. The vsv that controls the fuel pressure regulator...is it acceptable to remove this when using an afpr when performing bpu's? What are the possible negitive effects if removed?

2. The two vsv's have different part #'s but are they interchangeable? I've noticed that with no power to them, they route the same..

3. Does anybody have detailed pics of where and how exactly they mount under the intake?

Thanks for lookin!

 

[radiod]

I mounted mine on just two of the lower intake manifold lower bolts.

 

[bluepearl]

As Radiod said, they mount to the lower intake bolts.
In some situations, Possible hard start hot if removed.

 

[RotaryHead]

the one on the right is for the egr and you still need the other one hooked up to control fuel pressure while you drive

 

[SrBigbutt]

The plug for my fuel pressure vsv is broken. What issues will I see?

 

[isnms]

Question #


2. The two vsv's have different part #'s but are they interchangeable? I've noticed that with no power to them, they route the same..

3. Does anybody have detailed pics of where and how exactly they mount under the intake?

Thanks for lookin!

2. The connectors are keyed, so not interchangeable
3. The FPU VSV mounts way up under the manifold on against the head in oem configuration. Jason T posted a pic. It's kind of difficult to see but read suprra_girl post and then you will be able to spot it.

http://www.supramania.com/forums/showthread.php?t=454

 

[SrBigbutt]

I think my FPU vsv broke by trying to mount to the intake and it didn't reach. And being that the wires were brittle.

 

[gaboonviper85]

2. The connectors are keyed, so not interchangeable
3. The FPU VSV mounts way up under the manifold on against the head in oem configuration. Jason T posted a pic. It's kind of difficult to see but read suprra_girl post and then you will be able to spot it.

http://www.supramania.com/forums/showthread.php?t=454

Thank you very much!

 

[jdub]

To answer your 1st questions Gaboon, the purpose of the FP up VSV is to increase FP when coolant temps are hot:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=116

The VSV opens to atmosphere (same as if you disconnected the vac line) to increase FP for a hot start. The issue you may have is a difficult/no-start on a hot summer day.

 

[TurboStreetCar]

the one on the right is for the egr and you still need the other one hooked up to control fuel pressure while you drive

It only changes fuel pressure on startup and Jdub stated. Does nothing while driving.

 

[IwantMKIII]

To answer your 1st questions Gaboon, the purpose of the FP up VSV is to increase FP when coolant temps are hot:
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?S=FI&P=116

The VSV opens to atmosphere (same as if you disconnected the vac line) to increase FP for a hot start. The issue you may have is a difficult/no-start on a hot summer day.

I was under the impression the 'venting' function of this vsv was to eliminate fuel vapors and get rid of the air pockets, not necessarily just to increase FP.

 

[jdub]

Your "impression" is incorrect. Look at the routing of the vac lines to the VSV...how would it get rid of fuel vapor directly by "venting"?
(Hint: it's impossible)

It works exactly as I stated, the VSV vents to atmosphere and causes the FPR to raise FP...exactly the same as if you disconnect the vac line at the FPR for the TSRM FP tests. Any vapor or air pockets in the fuel rail would be purged (more quickly w/ increased FP) through the FPR to the return line to the tank.

 

[GrimJack]

I was under the impression the 'venting' function of this vsv was to eliminate fuel vapors and get rid of the air pockets, not necessarily just to increase FP.

Well, in a roundabout kind of way. The increased fuel pressure purges the fuel rail, sending any fuel that's heat soaked back to the tank faster than it would otherwise.

 

[MA70_Powa]

I havent had mine in there since day one of my engine swap (they vanished off my N/A motor ) and I've had no isssues whatsoever. Even on hot days -well, hot for here. probably not as hot as what you US boys can get.

 

[gaboonviper85]

It's been know to hit 104 deg F / 40 deg C here in Philly once in a blue moon.

 

[gaboonviper85]

2. The connectors are keyed, so not interchangeable
3. The FPU VSV mounts way up under the manifold on against the head in oem configuration. Jason T posted a pic. It's kind of difficult to see but read suprra_girl post and then you will be able to spot it.

http://www.supramania.com/forums/showthread.php?t=454

After very close inspection....the connectors are keyed but they are the exact same...i took all the spare vsv's I had (4) with all different mounting brackets and each one could fit front or back:-(