2 Of The 3 Are Capped

[CanadaCraig]

Hi Guys!! :)

I hope you're OK.

Take a look at a photo of MY engine and compare it to your own.

Notice the ONE vacuum line below the TRAC box?

One the Lexls.com site - the engine in those photos have THREE vacuum lines.

Two of the three are 'capped' on my engine.

What do those lines do and should I have THREE?!

Thanks,

Craig!! :)

[1990LS400]

Craig,

I suspect that the extra vacuum lines are related to the different emission controls on U.S. models vs. the emission controls on your Canadian-spec LS400. Looking at the sparkplugs tutorial photos on lexls.com I can see see quite a few differences in the engine "plumbing" from your LS.

Hey, your engine looks clean enough to use as a dinner plate!

[obergc]

My 93 is exactly the same, only one line connected to same port.

[1990LS400]

Well, then maybe it is related to model year since I (think) I remember my previous 1990 LS400 had all three lines instead of just one as on your 93 cars.

Here is a link to an engine photo of a 1990 LS400 which also shows three lines instead of one: http://buzztrader.com/showimage.cgi?1271&1..._69_10232_3.jpg

[Arkansawyer]

Ditto here on my '93. Two lines capped.

[j.barleycorn]

Yep, appears to be model year related, as I know my 1992 has all three in use.

My LS400 is outside right now (had the 4runner in the garage overnight after relacing the rear axle seals) so when I swap them out this evening I'll see what the exact deal is, but I believe the extra two lines run from the EGR valve/vacuum modulator and the VSV.

Sounds like there was a change to the EGR system beginning in 1993...