What Is This Part?

[AzHotLS]

I need to identify the part that is located behind the Diagnostic port. The part numbers printed on it are 90910-12076 and 184600-0621.

It is the part with the electric cluster that plugs into the top of it and has 2 hoses connecting to it (from front and top back)

Here is a photo from the gallery http://us.lexusownersclub.com/gallery/LS/L..._side_cover_off that shows it.

The small plastic canister sticking out of it from the back broke off. It looks as if there was glue on it where it must have been glued on previous to my owning the car.

About how much is it and what negative effects are there driving with it broken?

[kcpth]

http://www.lexls.com/tutorials/emission/egrfilter.html

That website will explain what each part is. As for what it does... well i can't really tell u other than the fact that it deals with emission controls. I dont know if it will affect performance wise. Perhaps someone else can give you a more detail explanation what will happen if it broke off. Good luck.

Tom ;)

[AussiLS400]

From an expreience i learnt from my wifes Previa if any of the the cars anti polution gear is not working it adds to fuel consumpion. The Previa has a almost identical layout. I had blocked tubes and after unblocking all the buildup and cleaning the bit you are talking about the car delivered about 15% better fuel economy although didn't seem to run any different. I believe the computer compentsates small problems that might occur.

[j.barleycorn]

Here's the page from the 1992 LS400 manual referencing the EGR section.

emissions_egr_system.pdf

I'm sure it does not answer your questions, but perhaps it will offer a bit more light on the subject.

I would guess your LS is the same configuration.

[lenore]

In California the car would fail smog due to high N O Gases. The Egr takes some of the exhaust and recirculates it into the intake to lower combustion temperatures and burn gases more completely.

[AzHotLS]

Thanks for the replies.

kcpth, the lexls tutorial mentions the VSV, but that's not my part. It's very similar but it's towards the front of the car and they don't look interchangable. I've attached a photo to more precisly identify it.

j.barlycorn, thanks for the PDF, I hadn't seen that before. My part isn't one of the items described. I circled it in an attached photo.

The "canister" that broke off looks like the filter on the VSV so while I need to take care of it, it may be okay in the short term. But I'd hate for too much dust getting sucked in and mess something up.

We're getting close. I hope that with my clarification, we can get it identified.

Edited December 30, 2005 by AzHotLS

[kcpth]

Sorrie i can't realli help... Never noticed that before. Perhaps someone else can shed some light to your answer. I'm assuming if u passed all ur inspections... n u dont notice anything bad about the drive... it should b ok... temporaily. Like what wut Aussie said... perhaps u'll lose on fuel economy... or release more smog into the air like Lenore mentioned.

[j.barleycorn]

Ok, 2nd try!

I searched all over the manual, and it appears the assembly you are describing is the Fuel Pressure Vacuum Switch Valve (VSV). I may be wrong, but from what I can see the component you had identified in one of your pictures as the VSV is actually the VCV, the control valve for the EVAP purge.

I tried to attach the exploded view of the cylinder head components page of the manual, but the file is too big.

I also googled your part numbers in a Lexus part list and the 12076 came back as a vacuum switch valve. The other part number (184600-0621) did not come up in the search (said it was not a Lexus part number). I see the number sequence on the first part was 5 digits-5 digits, while the 2nd was 6-4. Is the number correct?

All this is fine and dandy, but so far I can't find anything in the manual about this valve, or the filter. If I get some time later today I will look some more.

If you want me to email the cylinder head component .pdf, let me know.

[AzHotLS]

j.barleycorn, thanks for the offer, click my card for my email address. I don't think it's a VCV, but it's possible I suppose.

Attached is another photo showing the other side of the part that has the numbers on it.

[j.barleycorn]

Hi Az-

I emailed you the manual page I described, and a pic from my engine to make sure we are on the same page.

Seems like this should not be so difficult to figure out!? But, aside from the manual and my own curiosity, I probably am not much help, as I am new to these engines and never noticed this part before.

[ko90ls]

this might help. it for a 1990 but it is mainly testing and diagnosing.

emission_control_visual_inspection_procedures.pdf

[bicol-ini]

hi thats a VSV part number 90910-12076 86 bucks dealer part only,

[AzHotLS]

Thanks bicol-ini, a VSV it is then.

ko, thanks for the PDF.

j.barleycorn, I didn't get your Email for some reason. Hotmail probably blocked the attachment because it was too big. Thanks anyways.

Based on what your search found and confirmed by bicol-ini, a VSV it is.

There is another recent thread where someone is offering parts off of their '91 LS400. I contacted them and they've offered to send me the part.

Thanks all for your help.

[j.barleycorn]

Az-

I happened to find the specific page in the manual for the fuel pressure VSV this morning, and emailed it to you. Perhaps you didn't get the other email because it got filtered as spam? In case you don't get it, here is the description of what the switch does:

The ECU turns on the fuel pressure VSV to draw the air into the diaphragm chamber of the pressure regulator if it detects that the temperature of the coolant is too high during engine starting. The air drawn into the chamber increases the fuel pressure to prevent fuel vapor lock at high engine temperatures in order to help the engine start when it is warm. Fuel pressure control ends approximately 100 seconds after the engine is started.

Nice to learn something new everyday!

[93ls400walt]

Ok, 2nd try!

I searched all over the manual, and it appears the assembly you are describing is the Fuel Pressure Vacuum Switch Valve (VSV). I may be wrong, but from what I can see the component you had identified in one of your pictures as the VSV is actually the VCV, the control valve for the EVAP purge.

I tried to attach the exploded view of the cylinder head components page of the manual, but the file is too big.

I also googled your part numbers in a Lexus part list and the 12076 came back as a vacuum switch valve. The other part number (184600-0621) did not come up in the search (said it was not a Lexus part number). I see the number sequence on the first part was 5 digits-5 digits, while the 2nd was 6-4. Is the number correct?

All this is fine and dandy, but so far I can't find anything in the manual about this valve, or the filter. If I get some time later today I will look some more.

If you want me to email the cylinder head component .pdf, let me know.

If you still have the factory under the hood decal diagrams. You will see on the vacuum hose routing that there are two vac switching valves. Yours is one of the two.

[AzHotLS]

j.b, thanks for staying with me on this. With your persistence, we now know that while it is a VSV, it is the Fuel System VSV as opposed to the EGR System VSV. I did get your original email with attachments but I don't know why I didn't see them in my inbox before, oh well. But yes, we're talking about the same part. I attached the fuelpres.pdf file that you sent me.

Fuel System VSV is towards the front of the car and the EGR System VSV is towards the back.

The ECU turns on the fuel pressure VSV to draw the air into the diaphragm chamber of the pressure regulator if it detects that the temperature of the coolant is too high during engine starting. The air drawn into the chamber increases the fuel pressure to prevent fuel vapor lock at high engine temperatures in order to help the engine start when it is warm.

Being that I live in the desert and it gets HOT during the summer, I can see where the "FS-VSV" is needed.

Ok, so NEW question. What function does the filter do? It seems to only be used when air comes out of pipe E. No air seems to be drawn in from the filter, only out of. What is in the air that needs to be filtered?

"Battery voltage is applied :

The air from pipe E is flowing out through the air filter.

Battery voltage is not applied :

The air from pipe E is flowing out through pipe G."

As a side note, I noticed that the '90 & '91's don't have the VCV for Evap Purge, that third "thing" near the EGR.

fuelpres.pdf

[j.barleycorn]

Hi Az-

Yep, I saw the questionable need for the filter when I first saw the inspection procedure. I have no idea what would be filtered, unless it is burned/unburned fuel gases, and Lexus just wanted to protect our delicate noses in the rare instances the valve does it's thing.

You are in the unique position to find out what it does filter, though... just throw some volts at it and inhale! And of course, post the results! :D

[vissine]

Is there any other reason than polution to replace this VSV when it's filter broke off?