I recently have been battling the dreaded P0401 and ordered an OEM VSV with hopes I'd be able to replace it following the thread below. Seems easy enough right? Job only took the guy that wrote the steps about an hour. Here is his link and steps.
RMLCA - Rocky Mountain Land Cruiser 4x4 Association
I got a check engine light and found it was a P0401, EGR underflow.
The EGR valve itself tested OK by connecting a vacuum hose to it,
sucking on the hose, and observing that the engine almost died. The
posts that I found in the archives seemed to indicate that replacing
the VSV is the fix that everyone eventually gets around to for a
P0401, but that the VSV is nearly impossible to change without
removing the intake chamber. I decided to take a chance and replace
the VSV. I didn't find it to be particularly hard to replace the
VSV on my 1995 US FZJ80:
1) Remove the top bolt of the intake mainfold stay and loosen the
bottom bolt enough to let it swing out of the way.
2) Now that the stay is out of the way you will be able to see the
12mm bolt holding the front of the VSV bracket to the intake
chamber. There is enough room to get a box end wrench on the bolt
and remove it.
3) From under the engine you will have an unobstructed view of the
12mm bolt holding the back the VSV bracket to the intake chamber,
and you can remove it using a socket wrench and about 32 inches of
extensions.
4) Carefully unplug the wiring connection and hoses from the VSV
and its bracket. The space is tight, but you can reach one hand
into where the VSV is without a major problem.
5) The VSV and bracket will come out together. One Phillips head
screw holds the VSV to the bracket.
Reassembly is the reverse. The only problem that I encountered was
that some of my bolts were stuck pretty tight. The job took me
about an hour.
I got to step 4 and encountered an issue with the inability to properly remove the wiring connection with one hand from the VSV. I engaged pliers to assist and now have this to deal with.
At this point I am going to need to replace this small wiring harness and I'm still trying to "free" my VSV from this awkward as hell location.
I don't know how this guy was able to unplug the hose connection from the VSV either. My truck is a 1997 and these hoses simply don't slide off. Add that you have to do it all with one hand, blind and well the frustration continues.
Any suggestions at this point in the game? There is no way I am going to be able to remove those hose connections without causing damage to them.
RMLCA - Rocky Mountain Land Cruiser 4x4 Association
I got a check engine light and found it was a P0401, EGR underflow.
The EGR valve itself tested OK by connecting a vacuum hose to it,
sucking on the hose, and observing that the engine almost died. The
posts that I found in the archives seemed to indicate that replacing
the VSV is the fix that everyone eventually gets around to for a
P0401, but that the VSV is nearly impossible to change without
removing the intake chamber. I decided to take a chance and replace
the VSV. I didn't find it to be particularly hard to replace the
VSV on my 1995 US FZJ80:
1) Remove the top bolt of the intake mainfold stay and loosen the
bottom bolt enough to let it swing out of the way.
2) Now that the stay is out of the way you will be able to see the
12mm bolt holding the front of the VSV bracket to the intake
chamber. There is enough room to get a box end wrench on the bolt
and remove it.
3) From under the engine you will have an unobstructed view of the
12mm bolt holding the back the VSV bracket to the intake chamber,
and you can remove it using a socket wrench and about 32 inches of
extensions.
4) Carefully unplug the wiring connection and hoses from the VSV
and its bracket. The space is tight, but you can reach one hand
into where the VSV is without a major problem.
5) The VSV and bracket will come out together. One Phillips head
screw holds the VSV to the bracket.
Reassembly is the reverse. The only problem that I encountered was
that some of my bolts were stuck pretty tight. The job took me
about an hour.
I got to step 4 and encountered an issue with the inability to properly remove the wiring connection with one hand from the VSV. I engaged pliers to assist and now have this to deal with.
At this point I am going to need to replace this small wiring harness and I'm still trying to "free" my VSV from this awkward as hell location.
I don't know how this guy was able to unplug the hose connection from the VSV either. My truck is a 1997 and these hoses simply don't slide off. Add that you have to do it all with one hand, blind and well the frustration continues.
Any suggestions at this point in the game? There is no way I am going to be able to remove those hose connections without causing damage to them.
