Bought new vsv and vacuum modulator still problems??? (1 Viewer)

[newbielx450]

Hello all, I am extremely new to the land cruiser association I recently purchased a lx450 about 4 months ago engine light was on but I tested the code came up with the egr insufficient flow detected so I pulled the vacuum modulator and it was fried!, went to Lexus purchased new vsv and modulator changed vsv and modulator still same problem tested old vsv and it tested fine opens and closes perfect new vsv works perfect as well. I'm stumped I have been screwing with this thing all day i'm thinking of pulling the top plenum and starting from scratch possible misplaced vacuum line? I am begging for some info on this situation, I also checked the plug to the vsv it recieves no voltage at any time but maybe something thats intermittent?


If anyone has any info at all I would greatly appreciate it?

 

[scrowley]

Few things you can try doing that I know of:

- Take off throttle body and check to see if egr port is clogged
- Check to make sure egr holds vacuum
- Go through FSM procedures for egr system check

All these steps can be found searching on this forum

 

[ThaCrusher]

Hey I went through this for a while as well. Before you pull the plenum try one more free thing. Remove the temp sensor an clean it. I went through what you did as well. I even replaced the EGR. Then my mechanic said "lets try this" (cleaning temp sensor). Its been 6 months and no codes. Otherwise you need to pull the intake.

 

[ThaCrusher]

Hey I went through this for a while as well. Before you pull the plenum try one more free thing. Remove the temp sensor an clean it. I went through what you did as well. I even replaced the EGR. Then my mechanic said "lets try this" (cleaning temp sensor). Its been 6 months and no codes. Otherwise you need to pull the intake.

Sorry, pull throttle body not intake.

 

[Bendcruiser]

I have been searching for 5 months for an answer? I have code 71 EGR as well. My friend who is my mechanic is starting to think it's the Ethenol in the fuel we use and a 20 year old computer is not going to adjust for it? He told me in our last conversation "Put a piece of tape over the light on the instrument cluster"! My fj80 with 3fe engine (164,000 miles) runs great and cool with good gas mileage,he may be right?

 

[scrowley]

that is an interesting consept but if it was the case majority of the cruisers out there would have the light on for that code. It seems like ppl have gotten the code to go away with replacing or cleaning something in the system.

 

[Bendcruiser]

that is an interesting consept but if it was the case majority of the cruisers out there would have the light on for that code. It seems like ppl have gotten the code to go away with replacing or cleaning something in the system.

Well not all have them but it does seem to be prevelent? I have gone through the engine without a cure,yet? Maybe a California issue with all the emission junk?

 

[d0ubledown]

delete/bypass/remove the EGR if you dont have smog testing. its useles, robs your motor of power and fuel economy. although some here may tell you otherwise...dont believe them.

but if you absolutely MUST get it to work...

check all the vacuum lines & ports. esp the one that goes through the intake plenum from the modulator. that gets backed up. same with the port on the TB. hell, pull the plenum off anyway and give that puppy (and your TB) thorough cleaning. new lines all round. that should do the trick. dont be surprised if you still get the code though...

hopefully you can still return your VSV that you bought but didnt need

 

[rolliges]

="newbielx450"!, went to Lexus purchased new vsv and modulator changed vsv and modulator still same problem tested old vsv and it tested fine opens and closes perfect new vsv works perfect as well.
I am begging for some info on this situation,
I also checked the plug to the vsv it recieves no voltage at any time but maybe something thats intermittent?

How did you test the VSV?

 

[Billy Skaggs]

there is a post on that. i had same issue i replaced all egr componets still code. then replaced all vacuam switches and hoses still code. then temp senser no more code temp sensor was bad. its cheaper to buy your parts online delears bend u over. toyotapartseast.com still is cheapest and still has the diogram. brother site to toyotapartszone.com witch removed the diagrams buy a service manual it has all info u need @ sor.com 100.00 bucks.

 

[newbielx450]

I tested the vsv by sucking on one end and putting 12 volts to it to see if it closed both checked fine modulator was bad the diaphram was toasted!! found 3 vacuum lines with giant holes in them. I have decided that im pulling the plenum and cleaning and raplacing the lot. talked with toyota today they will take the vsv back unless someone wants to buy it? I will give a discounted price for mud members or anyone that owns a land cruiser!!. I noticed the air intake hose was dry rotted called toyota $108.00 so I'll probably end up replacing it. when the light comes on the truck runs like poop! and consumes tons of gas 8mpg max, so that is why I am trying to figure out the situation? gas is gold these days. When I shut the light off the truck runs great for about 2 days then the light comes on and all hell breaks loose. I appreciate the replies guys!! thanks much. Anyone close to Ocala wants to show me some tricks? I'll buy the beer!! cheers guys thanks for the info Ill keep ya'll posted.

 

[newbielx450]

I'm tempted to rip and tear the egr system off with all the knuckle busting that has been going on. but I have OCD and want everything to work like its supposed to. Another something i noticed was when I take the gas cap off there is a VERY high volume of air pressure in the tank, could this be a problem aswell? let me know guys thanks again!!.

 

[Bendcruiser]

I'm tempted to rip and tear the egr system off with all the knuckle busting that has been going on. but I have OCD and want everything to work like its supposed to. Another something i noticed was when I take the gas cap off there is a VERY high volume of air pressure in the tank, could this be a problem aswell? let me know guys thanks again!!.

It's not the problem,but you should change the charcoal canister.I did, no back pressure but still have the CEL.

 

[Chip]

Code 0401 is a PITA to diagnose, because it could be any of several things. I went through this 3 years ago and fortunately got it right the first time...after reading lots of posts/threads on this forum. Mine was the VSV. First, I replaced it... and within an hour of driving, the MIL came on again. I drove for another week with it on until I went back and checked all the hose connections. Well, I forgot to re-attach one of the hoses. Hooked it up and have been engine light free since then.
Best advice so far, from 'scrowley'... - Go through FSM procedures for egr system check.
Also, air pressure release always occurs when I open the cap on mine. The emptier the tank when opened, the greater the air pressure release.

 

[newbielx450]

I'm sorry what is FSM? "I'm new I don't know what to do" Joe Dirt!.

 

[mahalkita]

I'm sorry what is FSM? "I'm new I don't know what to do" Joe Dirt!.

Field Service Manual - you can download here on this forum (search for FSM) or from Toyota online for 10 bucks.

You can buy the vacuum lines in bulk, not expensive at all! Just replace ALL of them and also the big cracking intake hose. I assume you have a vacuum leak somewhere. Can check that with a cheap vacuum pump from Harbor Freight.
Best is to remove all the emissions cr*p though!

 

[newbielx450]

I'm really tempted to remove everything once done will it affect the cpu? and i seen something on removing the egr #### is there something to trick the egr temp sensor? jumper wire perhaps?.

 

[grizzlygibbs]

Lots of info and posts on this hashing out the effects of EGR removal posted recently. Do a quick search or scroll through the 80's section and you will find what you need. There is a resistor mod to trick the temp sensor the other threads will be more helpful and help you decide on what you are describing far better than I can. Lots of expertise on both sides, I am undecided but I fixed my 401 with plenum removal, cleaning of temp sensor and upper plenum, vsv replaced as mine tested bad, a couple fresh vacuum lines and I also did the fuel filter while I was in there. Hope this helps.

 

[Dbarr4lsu]

I'm really tempted to remove everything once done will it affect the cpu? and i seen something on removing the egr #### is there something to trick the egr temp sensor? jumper wire perhaps?.

There are two hoses that run from the throttle body to the vacuum modulator...they connect to a metal elbow plug. Pull the plug and clear the pin sized hole with a needle. This took care of my problem. This was after I changed out the VSV, vac modulator, EGR and other hoses. I only pulled the one on the right (I think) and cleared the tiny hole.

Hope this helps.

 

[2 E L O]

There are two hoses that run from the throttle body to the vacuum modulator...they connect to a metal elbow plug. Pull the plug and clear the pin sized hole with a needle. This took care of my problem. This was after I changed out the VSV, vac modulator, EGR and other hoses. I only pulled the one on the right (I think) and cleared the tiny hole.

Hope this helps.

Are you referring to the vacuum port elbows that are on top of the throttle body?